Star-Splitters

On to the second part of a look at some STT objects in Lacerta. In case you missed the first part, you can get to it by clicking on this link.

We’ll get started with OΣ 459 (STT 459), which is located in the southern sector of the Lacertan lizard.

Stellarium screen image with labels added, click to enlarge.

We’re going to start at 4.15 magnitude 1 Lacertae, which is located at the south tip of the constellation, and then follow the constellation diagram line that leads toward the north.  That line comes to a halt at another similarly bright star with a magnitude of 4.50 which surprisingly has no commonly used identification other than h 1746 (HJ 1746), a pleasing double star I covered a few years ago in this post. But at the moment we’re going to use it as a jumping off point to reach OΣ 459. Here’s our chart:

Stellarium screen image with labels added, click for a larger view.

Starting at h 1746, move west 30’ to 7.25 magnitude HIP 109543 and then continue west a full degree to reach 7.67 magnitude HIP 109014, which is paired with 7.73 magnitude HIP 109031 to the north. From that last star, a 25’ hop due west will land you on OΣ 459, which is shadowed to its south by 8.43 magnitude HIP 108833. For reference, there’s another dim pair of stars another 25’ further west, 7.65 magnitude HIP 108867 and 7.11 magnitude HIP 108695.

OΣ 459 (STT 459)      HIP: 108841   SAO: 71981
RA: 22h 02.9m   Dec: +39° 34’
Magnitudes: 8.2, 10.8
Separation:  10.6”
Position Angle: 196°  (WDS 2010)
Distance: 1884 Light Years (GAIA)
Spectral Classification:  A is A0

The white glow of OΣ 459 and its companion is at the center of this sketch, with one of our navigational stars, HIP 108833 parked at the south edge of the field of view (left in this sketch). North and south are reversed in this refractor view, click to get a better look.

With a difference of 2.6 magnitudes and a decently wide separation of 10.7”, this is not a difficult pair to split. I spied the secondary quickly with an 18mm Radian (84x) in my six inch refractor, but increased the magnification to 152x with a 10mm Radian in order to provide a more pleasing frame for the image. My search for a star of similar brightness to the OΣ 459 secondary eventually landed on UCAC4 649-106803, which has a UCAC4 Vmag (visual magnitude) of 11.150, so it appears the WDS value of 10.8 for the secondary is about right.

This pair was discovered by Otto Struve in 1845. He took two measures at that time, coming up with separations of 10.51” and 10.80”, and position angles of 197.8 and 196.5 degrees (p. 182 of this source). Compared with the most recent WDS measure of 2010, there’s been virtually no change in this pair, which is not surprising given its distance of 1884 light years.

Our next move is to a considerably more complicated star, OΣ 465.  To get there we first need to head north to 4.44 magnitude Beta (β) Lacertae, which is located at the north tip of the Lacertan diamond (here’s the wide view again to get you headed in the right direction).

Stellarium screen image with labels added, click to enlarge.

From Beta (β) Lacertae, which is located at the lower left center of the chart, it’s a two degree southwest leap (2° 9’ to be precise) to OΣ 465 (STT 465). You’ll find it 38’ south and slightly east of 5.38 magnitude HIP 109521, which is the first star you’ll come to on the southwest leap that’s similar in brightness to Beta (β) Lacertae. HIP 109521 is also known as h 1741 (HJ 1741), which is another double star we’ve looked previously and is in the same post referred to in the second paragraph above. As you scan the OΣ 465 chart, notice that 4.58 magnitude 4 Lacertae and 4.44 magnitude Beta (β) Lacertae from a triangle with STT 465 at the western tip, which should help to make sure you’re in the right place.

OΣ  (STT 465)     HIP: 109586   SAO: 51749
RA: 22h 12.0m   Dec: +50° 12’
Magnitudes  AB: 7.30, 10.55   AC: 7.30, 13.30
Separation   AB: 12.80”           AC: 17.80”
Position Angle   AB: 317°  (WDS 2010)   AC: 233°  (WDS 2003)
Distance: 2118 Light Years (Simbad), 4025 Light Years (GAIA)
Spectral Classification:  A is F0

You’ll need to enlarge this sketch by clicking on it in order to catch glimpses of the B and C components. This is a rather close approximation of the visual difficulty I experienced while trying to pry the two faint companions loose from the primarial glare. We’re dealing with a wider range of magnitudes here than we did on the previous star, so be prepared to strain your visual receptors just a bit.   (North and south reversed again to match the refractor view).

I’ve paid three visits to this triple star and each time was able to catch B pretty quickly in my six inch refractor with averted vision, hovering at the edge of the glare from the primary, but I needed 152x to do it. With a bit more concentration I even managed to capture it visually with direct vision for short periods.

My search for comparison stars landed on the two UCAC4 stars identified in the sketch to the west of the primary (above it in the sketch). Trying to keep B in view, whether with direct vision, or especially with averted vision, while comparing it to a similarly faint star is just a bit challenging to say the least, and can be a dubious process, as you’re about to see.  I finally decided B is about midway between the two UCAC4 stars in brightness.

UCAC4 701-104020 has a UCAC4 Vmag of 11.518 and UCAC4 702-100946 a Vmag of 12.589, which would make B about 12^th magnitude, or 1.5 magnitudes fainter than the WDS value, which really seems unlikely because B didn’t impress me as being a full magnitude fainter than UCAC4 701-104020.  So it looks as though the 12.589 Vmag value for UCAC4 702-100946 may be an error. Adding to my doubts that B is 1.5 magnitudes fainter that the WDS value is the 10.546 UCAC4 Vmag for B. We never got around to measuring the magnitude of B, so I’m tempted to say the WDS value for B is probably about right, especially considering the experience I’m about to describe with the C companion.

That one was a real chore, but I managed to latch onto it a couple of times. If the 13.30 WDS magnitude is correct, there’s no way I would have seen it in my six inch refractor. More than likely it’s in the 12.7 to 12.8 range, which would be about at the limit of what I can glimpse in that scope while trying to see around the edges of the seventh magnitude glow of the primary. UCAC4 702-100946, with it’s supposed Vmag of 12.589, was nowhere as difficult to see, which is another reason I have doubts about the accuracy of that magnitude.

At any rate, comparing stars as faint as these, especially when some of them are imbedded in the glare of a primary, in order to arrive at a magnitude estimate can sometimes produce more questions than answers.  It’s no wonder I found myself muttering in the damp darkness about the fickleness of faint stellar magnitudes while fighting off visions of a comfortable seat beside a warm fire with a good book and a hot cup of tea.

I don’t know how damp the darkness was when Otto Struve measured the B component in 1848, but according to Hussey’s account (p.191) he came up with separations of 15.26” and 15.38” and position angles of 324.1 and 324.6 degrees, which is notably different from the 2010 WDS numbers of 12.8” and 317 degrees.

Click to enlarge.

There seems to be something fickle here, too, so let’s begin by looking at the two distances I’ve listed on the last line of the data above for OΣ 465.  You’ll notice there’s a huge difference between the Simbad and the GAIA distances, but even if you go with the closest distance of the two, the primary of OΣ 465 is too far away to display any significant proper motion in the 162 years between Otto Struve’s 1848 measure and the 2010 WDS measure. I looked at some archived copies of the WDS and found there’s a consistent change in the separation and position angle of the AB pair, which is shown just above at the right.  That list shows the average of Otto Struve’s two 1848 measures, as well as 1867 and 1898 measures by Dembowski and Hussey, respectively, which come from p. 191 of Hussey’s book. It’s quite possible B is a foreground star and is slowly moving in front of the primary, which would make this an optical pair and account for the steady change in separation and position angle. GAIA doesn’t have any parallax data yet on B, so without that crucial piece of information, there’s no way to be certain at this point where it lies in relation to the primary.

As for who added C, it took some digging, but persistence paid off. The WDS shows the first measure of the AC pair was made in 1908, which is a strong hint that S.W. Burnham was involved. However, I had no luck in finding it in his 1913 Proper Motion Catalog, which is the only catalog he published after 1908. So I turned to R.G. Aitken’s 1932 New General Catalogue of Double Stars Within 120° of the North Pole and tracked down OΣ 465 on page 1364 of the second volume. And sure enough, the catalog entry identified Burnham as the source of the first measure, including the actual numbers, which match the WDS data. And unlike the AB pair, those numbers are pretty close to the 2003 measures in the WDS, which again points to B as the half of the AB pair responsible for their gradual change.

On to our last STT object in this trip through Lacerta. You’ll find OΣ 472 one degree almost due east of Beta (β) Lacertae, and you’ll skirt past the very small open cluster NGC 7296 on the way. Here’s our previous chart once again.

OΣ 472 (STT 472)     HIP: 111058   SAO: 34519
RA: 22h 29.9m   Dec: +52° 25’
Magnitudes  AB: 6.63, 11.50    AC: 6.63, 12.60
Separation   AB: 12.90”            AC: 12.50”
Position Angle  AB: 300° (WDS 2013)    AC: 356°  (WDS 2013)
Distance: 404 Light Years (Simbad, no data in GAIA).
Spectral Classification:  A is G8
Note:  AB is LEO 53, AC is STT 472

Again, you’ll have to enlarge this sketch by clicking on it and then looking closely at the one o’clock position to see a small speck of light. That’s the C component, the one discovered by Otto Struve. North and south reversed once more to match the refractor image.

I’ve looked at this triple star twice, about a year apart, and had no luck whatever at spying the B component. C wasn’t easy either, but with persistent averted vision and parallax-induced patience I managed to to pry it out of the primarial glare both times. I found it was very similar in magnitude to UCAC4 713-102498, which has a UCAC4 Vmag of 12.288. So it’s possible the C component is slightly brighter than the WDS value of 12.50.

On the other hand, the B component, located at virtually the same distance as C, is pretty clearly considerably fainter than the WDS value of 11.50. The only photometric data available on B is a UCAC4 f.mag of 13.924, which is a definite hint that B is somewhere in the 13.5 magnitude range.

Click to enlarge.

The AC pair first appeared in Otto Struve’s 1845 catalog with an estimated separation of 15” and no position angle (see excerpt at right).  The first published measure of the pair was made by Baron Dembowski in 1867, 15.80” and 365.8 degrees (p.192 of Hussey). OΣ 472 was later rejected in the second edition of the Pulkovo catalog because it was decided the separation of the pair exceeded the catalog limit of 16”, so apparently there was a measure made between 1843 and 1867.

As for the ear-catching LEO 53 (no association with Leo the Lion of constellation fame), it was pried out of the primary’s radiant glare in 1928 by Frederick C. Leonard, using the 60-inch reflector on Mt. Wilson. However, at Leonard’s request the actual measures were made by Aitken using the 36 inch Lick refractor. Leonard made a total of 56 double stars discoveries between 1917 and 1943. Because his published record of LEO 53 goes into more detail than is usual for a new double star measure, I thought it would be worth while to include it below in its entirety (source).  Notice that Leonard estimated the magnitude of B to be ±13.5 at the time of discovery.

That wraps up Lacerta for now, but we’re not yet done with Otto Struve who will be back shortly to take us on a tour of four of his discoveries in Cepheus.

Clear skies and tolerable temperature! 😎

Filed under: 4. Choose a Constellation:, Lacerta | Leave a comment »

It’s rather ironic that I find myself back in Lacerta once again, which is the scene of the last post I wrote here several months ago. But this is an intriguing little constellation, dim though it is, and is well worth spending some time here. This time we’ll concentrate on six of Otto Wilhem von Struve’s more challenging discoveries. The challenge here isn’t feeble starlight (with one exception) as much as the more dreaded difference in magnitudes. Fortunately the stingiest separation is 10.7”, so we have a fighting chance to separate these pairs. You’ll need a minimum of six inches of unobstructed aperture to resolve these stars, although given very dark skies, great transparency, and stable seeing (in other words, rather rare atmospheric cooperation), you might get by with five inches.

As historical background, Otto Struve published the first catalog of his discoveries in 1843 with a lengthy title which was typical of the era, Catalogue de 514 Étoiles Doubles et Multiples Découvertes Sur L’Hémisphère Céleste Boréal par La Grand Lunette de L’Observatoire Central de Poulkova. Fortunately, the title which has come into common usage is The Pulkova (or Pulkovo) Catalog. This particular survey of double stars was actually started on August 26^th, 1841, by Otto’s father, Friedrich Wilhelm Struve, who turned it over to his son within a month. There were several additions and modifications to this catalog over the next decades, which resulted in the printing of subsequent editions, including a supplement of much wider pairs. Also lending a hand and providing many of the measures of these pairs was Johann Heinrich Mädler.

Let’s start by getting situated in Lacerta, which lies in the dim region between Cepheus and Cygnus. Even though the area is sparse in regard to eye-catching magnitudes, the north end of Lacerta lies in a star strewn stream of the Milky Way as it meanders through Cygnus, Cepheus, and Cassiopeia.

Stellarium screen image with labels added, click to enlarge.

Note the directions indicated in the top left hand corner of this chart. Astronomical west is always the direction in which the constellations are rotating, which explains why it’s pointing in the direction shown. This is a depiction of the scene in late August or early September, when the constellations are slowly rotating toward the top of the chart.

Stellarium screen image with labels added, click to enlarge.

If you’re having trouble pinning down the Lacertan Lizard, notice that a line drawn from Beta Cephei through Delta Cephei will take you right through the center of the distinctive Lacertan parallelogram. Also, a line drawn from Delta Cygni (out of view at the upper right hand corner) through Deneb will take you to the southern tip of Lacerata.

Our first stop is OΣ 477, which lies a couple of degrees north of 11 Lacertae:

Stellarium screen image with labels added, click for a better view.

If you look closely at the chart above, 4.46 magnitude 11 Lacertae forms a triangle with 6.38 magnitude HIP 111753 and 6.55 magnitude HIP 111428. OΣ 477 stands out distinctively just half a degree west of HIP 111428.

OΣ 477 (STT 477)     No HIP Number    SAO: 52303
RA: 22h 43.5m   Dec: 46° 02’
Magnitudes  AB: 7.43, 12.20   AC: 7.43, 11.24   CD: 11.24, 12.70
Separation   AB: 22.50”          AC: 182.70”         CD: 10.40”
Position Angle  AB: 262° (WDS 2015)  AC: 344° (WDS 2002)  CD: 127° (WDS 2015)
Distance: 256 Light Years (GAIA)
Spectral Classification:  A is F6

As I mentioned above, you need six inches of unobstructed aperture to spy the dim companions featured in this series. So you have to look closely to see the twelfth magnitude B companion, as well as distinguishing the difficult CD pair. Clicking on the sketch will enlarge it and make things much easier. (North and south reversed to match the refractor image).

This was my third visit to this multiple star, and each time was an improvement over the time before. My first visit was on 8-21-2015, during which eleventh magnitude C was the only component I could catch. I came back a couple of weeks later (9-7-2015) and that time, with a determined application of averted vision, I pried 12.2 magnitude B out of the primarial glare, but still couldn’t distinguish 12.7 magnitude D clinging to C. My most recent visit, almost exactly a year after the second, was under much improved seeing conditions. Not only was B much easier to see, but D was also obvious when I looked closely. In fact all three components were such a breeze that I was surprised to see how difficult they had been when I looked at my notes from the prior visits.

Not only were the three components more cooperative, but I also picked out the faint star which is shown just to the left of B in the sketch, which was totally absent during the earlier encounters with OΣ 477. That star is identified in Aladin as UCAC4 681-126049 with a visual magnitude of 13.073. Combining the J and K magnitudes for it results in a similar magnitude of 13.021, so it’s safe to call it a 13.0 magnitude star. Again, it’s amazing the difference a cooperative atmosphere can make – sort of what you might call the difference between night and day.

By the way, a comparison of various UCAC4 and NOMAD-1 magnitudes for B, C, and D all resulted in remarkable consistency, each coming in within a few tenths of a magnitude of the WDS values, so all of the magnitudes shown in the data line above are very reliable.

Getting back to 13.0 magnitude UCAC4 681-126049, you might wonder why Otto Struve ignored that one at the time he observed B. There’s an easy answer to that question. When his father, F.G.W. Struve, started this survey of double stars, he established specific criteria, among which was a separation limit of 16” for companions fainter than ninth magnitude (p.16 of this source). Aladin shows a separation of 36.28” between UCAC4 681-126049 and the OΣ 477 primary, so that explains that. Otto Struve later added a supplement to the Pulkovo Catalog for wider pairs, but he apparently didn’t come back to this one. (The stars in that supplement were assigned a prefix of OΣΣ, which in WDS jargon has been transformed to STTA).

Of course that raises questions immediately with regard to the B and CD components since they’re well outside the 16” limit. With regard to the CD pair, the answer is pretty straight-forward: it was added in 1880, most likely by S.W. Burnham, although I haven’t been able to pin that down definitively. As for B, the answer is A – which is a cryptic way of saying that A has a lot of proper motion. In fact, that can be illustrated by the separation of the AB pair at the time of discovery in 1846, when it was a much tighter 9.6” (with a considerably different PA of 123 degrees). The most recent data, which comes from the GAIA catalog, shows the A component with a proper motion of +185 -009 (.185”/yr east and .009”/yr south), which means it’s moving eastward at a pretty good pace. The effect of that motion is easy to illustrate by using the Epoch tool slider in Aladin to compare and contrast the relative positions of the AB pair in 1846 and 2016:

Aladin image with labels added, click to enlarge.

Notice the red circles represent the positions of the two stars at the two dates shown. More proof that the heavens change just like everything else, albeit at a snail’s pace. Also, the separation between A and UCAC4 681-126049 in 1846 was 43”, which again illustrates why it wasn’t included in 1846 when Otto Struve measured the AB pair.

Now that we have that covered, we’ll move on to OΣ 479, also known as STT 479, AKA HN 42, AKA 13 Lacertae. Starting again at 11 Lacertae, you’ll find OΣ 479 is located 2 ½ degrees to the southeast. It and 11 Lacertae form a triangle with 4.95 magnitude 15 Lacertae. (Here’s our previous chart again).

OΣ 479 (STT 479) (HN 42) (13 Lacertae)
HIP: 112242    SAO: 52317
RA: 22h 44.1m   Dec: 41° 49’
Magnitudes: 5.21, 10.9
Separation:  14.4”
Position Angle: 130°
Distance: 256.5 Light Years (Simbad)
Spectral Classification:  A is G8 (WDS)

Again, you have to look closely to see the secondary, which is a bit more difficult than the secondary in the previous sketch. (North and south reversed to match the refractor image, click for a better view).

I had very little difficulty with this pair on the night I made the sketch above at 201x, which wasn’t the case a year earlier when I looked at it. On that night the secondary was immediately visible at 84x, but it decided to become difficult when I increased the magnification. At 152x, it vanished into the primarial glare, and then reappeared sporadically when I dropped back to 127x. It was more cooperative at 109x, but still a bit elusive, so I went back to 84x and was able to see it most of the time with direct vision, at other times only with averted vision.

There’s a huge difference in magnitude between the two stars, somewhat comparable to seeing the secondary of Polaris in a 50mm refractor. That pair has a Delta_M of 7.06 (magnitudes of 2.04 and 9.1) vs. 5.69 for this pair, which is fainter, so the comparison is not quite exact, but it will give you an idea of what to expect. However, I estimated the secondary to be at least a full magnitude fainter based on comparison with two nearby stars, which sheds some light on the comparison with Polaris. B appeared to me to be slightly fainter than UCAC4 659-108762 (which has a UCAC4 Vmag of 11.640) and slightly brighter than UCAC4 660-110091 (with a Vmag of 12.818), so the actual magnitude most likely lies somewhere in between.

William Herschel appears to have been the first to come across this pair of stars, having looked at them on October 17th, 1786. However he didn’t publish that observation until 1822, assigning a catalog number of H N 42 to it. His remarks on the pair were rather brief: “13 Lacertae has an extremely small star following, 3d class.” (p.171 of 1822 catalog). John Herschel also looked at 13 Lacertae in 1828, providing an estimated separation of 12” with a PA of 132.9 degrees. The first actual measure of the pair was made by Otto Struve in 1849. He recorded a separation of 14.57” and a position angle of 129.2 degrees. John Herschel recorded another measure of the pair that same year, turning in a separation of 14.70” and 129.1 degrees. Comparing those 1849 measures to the most recent 2012 WDS data shows very little change over the past 167 years.

On to our last star now. We’ll head south from OΣ 479 (with a bit of a tilt to the west) for a distance of 1° 40’ to 5.82 magnitude 12 Lacertae, then continue in the same direction another 1° 15’ to 4.89 magnitude 10 Lacertae, and then angle southeast for a distance of 1° 28’ to 6.03 magnitude HIP 111869. You’ll see OΣ 475 at the western corner of a triangle it forms with HIP 111869 and 6.65 magnitude HIP 111864. (The previous chart once more).

OΣ 475 (STT 475)     HIP: 111828   SAO: 72569
RA: 22h 39.1m   Dec: 37° 23’
Magnitudes  Aa, Ab: 6.83, 10.52   AB: 6.84, 10.80
Separation   Aa, Ab: 0.60”            AB: 16.10”
Position Angle  Aa, Ab: 50° (WDS 2009)    AB: 73°  (WDS 2008)
Distance: Unknown  (negative parallax)
Spectral Classification:   A is B2
Note: Aa, Ab is HDS 3216, AB is STT 475

And again you have to look closely to see the B component of this pair (it’s hiding in the glow of the primary between the four and five o’clock position). Notice both HIP 111869 and HIP 111864, which we used to locate OΣ 475, are in the field of view with it. (North and south reversed once again, click for a much better view).

I had little problem with the secondary during my two year-apart-observations since it popped into view immediately at 84x both times. I estimated it to be very similar in magnitude to UCAC4 638-120691 (located 9’ northwest), which has a Vmag of 11.008, so it appears the WDS magnitude of 10.8 is about right. Otto Struve first measured this pair in 1847 at 15.53” with a position angle of 72.8 degrees. John Herschel showed up here as well that same year, turning in a separation of 15.66” and a PA of 73.6”.

As for the Aa, Ab pair, good luck. A separation of .60” wouldn’t be out of reach for a large aperture dobsonian –- except for that annoying 3.69 magnitude difference between the two components. The HDS prefix refers to the Hipparcos Double Star survey, which first detected it in 1991. With a total of four observations recorded in the WDS, you can at least rest assured the secondary is really there if you launch a search for it.

Also hovering in the southwest quadrant of the field of view is an evenly illuminated pair, AG 284 (WDS 22387+3718), which has magnitudes of 9.86 and 9.94, separated by 26.3” with a PA of 230 degrees (WDS 2008 data). Your double-starred vision should have no problem latching onto those two.

That’s it for the first half of this tour – click here to continue to the second half.

Clear Skies! 😎

Filed under: 4. Choose a Constellation:, Lacerta | 1 Comment »

It had been a long while since I last took a stroll through Lacerta, so I had to grab my well-worn copy of Sky and Telescope’s Pocket Sky Atlas and relocate the constellation’s dim outline between Cygnus and Cepheus.   Lacerta is not one of those constellations that draws attention, which is unfortunate since the Milky Way runs through about 90% of its stellar real estate – meaning it has more than its share of double stars and open clusters. I was back to check on the Lacertan lizard once again because of a question about the magnitude of one of the components of 8 Lacertae, which in keeping with Lacerta’s rich stellar tradition, also has more than its share of stellar companions.   And as long as I was there, I decided to poke around and see what else I could see, which led to a magnitude of additional questions.

Even though it’s the first part of December as I write this, from my forty-five degree latitude Lacerta is almost directly overhead at 7 PM, parked in a holding position between Cygnus, Andromeda, and Pegasus, and Cepheus.

Stellarium screen image with labels added, click to enlarge.

A line drawn from Beta (β) Cephei through Zeta (ζ) Cephei will actually lead you directly to 8 Lacertae:

You can also draw a line from Delta (δ) Cygni (just out of sight at the upper right of the chart) through Deneb, which will just miss the southern edge of 8 Lacerate. (Stellarium screen image with labels added, click to enlarge).

But because Lacerta is a dim constellation . . . . . .

Stellarium screen image, labels added, click for a larger view.

. . . . . . you might find it easier to aim an 8×50 or 9×50 finder at 4.5 magnitude 6 Lacertae, move northeast a few degrees to 4.5 magnitude 11 Lacertae, and then drop southeast to 5.1 magnitude 13 Lacerate, using 5.0 magnitude 15 Lacertae as a reference point, and then move south to 5.3 magnitude 12 and 4.9 magnitude 10 Lacertae, which form a triangle with sixth magnitude 8 Lacertae parked in the west corner.   That way you’ll be sure to land on the right star at least.   There should be little chance of confusing 8 Lac with another star since “A”, “B”, and “E” are bright and very obvious:

8 Lacertae  (AB is H IV 86)      HIP: 111546   SAO: 72509
RA: 22h 35.9m   Dec: +39° 38

Distance:  “A” is 2160 Light Years; “E” is 428 LY (Simbad)
Spectral Classifications:  “A” and “B” are B2, “D” is A0, “E” is F0
Notes: Mag of I changed from 11.0 to 13.3 as of 10-29-2015
Magnitudes of GJ are reversed in WDS, should be 12.99 and 14.08

In a mid-October email from Mike Hyrczyk via Chris Thuemen, Mike mentioned he had looked at 8 Lacertae and found the “I” component wasn’t visible in his six inch refractor. At the time, it was listed in the WDS at a magnitude of 11.0, normally well within reach of a six inch scope. That evening, I pointed my six inch f/10 refractor at the complex star and, at 152x, confirmed Mike’s observation. I tried higher magnifications – 253x, 365x, and 380x – and may have had a brief glimpse of the fickle star, but there was no doubt it was fainter than the WDS’s 11.0 magnitude. Chris used a 9.25 inch SCT the following night and basically had the same experience, although he may have detected an elongation in the DI pair. Chris also noticed the magnitudes of the GJ pair were reversed in the WDS, which hasn’t been corrected as of this writing.

Given the 10.10” separation listed for the DI pair, experience told me that a magnitude of 13.0 was about the brightest “I” could be, if in fact I had actually seen it with my six inch refractor in the combined AB glare. A check of photometry records in the UCAC4 catalog showed magnitudes of 13.828 (f.mag) and 13.598 (J and K converted to visual), which were too faint for me to have had a glimpse of the star. I sent what information I had to Bill Hartkopf at the USNO/WDS, who consulted additional photometry records, arriving at a magnitude of 13.30 for “I”.

So — after that long introduction, it’s about time we took a look:

“A”, “B”, and “E” are the stars that catch your eye on first view, all of which are white, followed by “C” and “D”. You have to look a bit closer to get your first glimpse of “F”. The missing “I” component is both too faint and too close to “D” to be seen here. There are two more faint pairs to the south of 8 Lac, neither of which are cataloged in the WDS as double stars. (East & west reversed, click on the sketch for a better view).

There’s also an excellent photo and discussion of the 8 Lacertae complex on page 52 of the November issue of Sky and Telescope. Sue French was unable to see “I” with a 10 inch reflector, but found a fifteen inch scope brought it into view, which supports the WDS magnitude change to 13.30.   Sue also noticed the error in the WDS listing for the GJ pair.

8 Lacertae has an interesting history. Sir William Herschel was the first to record it for posterity, cataloging the AB pair as H IV 86 in 1782 (source, sixth title from the top):

His 84° 30’ south preceding works out to a present day figure of 185° 30’, which is a good match with the current WDS figure, but his separation of 17” 14’” puts the AB pair five arc seconds closer than the WDS data. He describes six stars, which probably correspond to the A through F pairs, although his description of their relative magnitudes is difficult to follow. The Latin phrase at the top of his catalog entry translates as “In the middle of the tail”, which seems to indicate a slightly different configuration for Lacerta than what I show above in the first chart.

Click to enlarge the image.

Sirs John Herschel and James South made two observations of 8 Lacertae in September of 1823, which are shown at the right (source, last title on page).  Their measures of AB, which are summarized near the bottom of the page, are in line with the current WDS data, as are their measures of the AD pair (145° 15’, 82.52”, which they refer to as AC).   They seem to have entirely missed the closer 10.38 magnitude star now referred to as “C”.

At the bottom of that same page, they refer to an erroneous measure of the AB pair made by Piazzi in 1800 (212° 58’ and 19.072”). Admiral W.H. Smyth also refers to that error on pp. 519-520 of his Bedford Catalog, as well as William Herschel’s 1782 PA error. Relying on his distinctive pre-Victorian vocabulary to make the point, he wrote: “Here the anomalies are palpably owing to error, and the fixity of the objects appears unquestionable.”

The Admiral was irrefutably correct in regard to the “unquestionable fixity” of the objects.   Given the 2160 light year distance of “A”, little proper motion is exactly what would be expected.   Simbad doesn’t provide a distance for “B”, but it does show “E” to be at 428 light years, which is also far enough away that minimal proper motion would be the norm. I checked the most recent PM data available, which comes from the USNO’s URAT1 catalog, and it confirms the minimal motion for each of the stars:

Aladin image with labels and data added, click to make the text more legible.

“E” shows the most motion, which again is to be expected since it’s four times closer to us than “A”.   There are no parallaxes available in Simbad on the other components of the system, but judging by their slight motion, they may well be about the same distance as “A”. And at those distance, it’s impossible to come to any conclusion on shared physical motion based on the PM numbers.

Before heading out into the night air to look at 8 Lacertae, I used Sky Tools 3 to take a quick look around the neighborhood for other interesting stars, and quickly found an intriguing multiple star, ROE 47, located just 41’ to the west (here’s our third chart again).   So give your scope a careful nudge in that direction and you’ll be greeted by a sixth magnitude star with several faint companions.

ROE 47        HIP: 111259   SAO: 72446
RA: 22h 32.4m   Dec: +39° 47’

Distance: 684 Light Years
Spectral Classification:  “A” is A6
Notes: Mag of C changed from 10.2 to 12.4 as of 10-29-2015
Mag of D changed from 11.36 to 12.2 as of 10-29-2015
Mag of E changed from 9.90 to 12.3 as of 10-29-2015

This one had what you might call a magnitude of problems, but before wrestling with that issue, let’s take a look:

“A” was very white; “C” was very faint and mainly an averted vision apparition; “B” was distinct; and “D”, which was just a bit easier to see than “C”, was marginally duplicitous at 152x, but it cooperatively separated at 253x with a 6mm Astro-Tech/Sterling Plössl, as shown in the insert below the insert at the right. (East and west reversed once more, click on the sketch to improve the view considerably).

It didn’t take but a few seconds to realize that some of the fainter components I was looking at were fainter than the WDS data said they were. As the “C” component flickered in and out of view, I could see it was clearly fainter than the 10.2 magnitude then listed for it in the WDS. There was also something clearly amiss with “D”, which wavered between direct vision and averted vision, meaning it was also fainter than the WDS’s 11.36. And “E”, which was listed at a magnitude of 9.9, was not the conspicuous speck of light it should have been – in fact, it should have been over-powering “D”.   After I separated the DE pair at 253x, it was clear they were both about the same magnitude – so 9.90 was nowhere close to being correct. Chris Thuemen also looked at ROE 47 and basically came to similar conclusions.

There’s a huge amount of photometric data available in both the NOMAD-1 and the UCAC4 catalogs, so I turned to both of those to see what I could find.   Looking at “C”, I found data pointing to a magnitude of 12.3. In the case of the DE pair, the UCAC4 Vmags, which are normally very dependable in this range, showed 11.358 for both stars, which seemed too bright to me.   The UCAC4 f.mag and the J & K visual approximations pointed toward a magnitude of 11.9 to 12.0, which struck me as being closer to what I had seen.

Click to enlarge and make the data more legible.

I sent off what I had to Bill Hartkopf at the USNO/WDS, who used additional data to make the changes I’ve listed at the bottom of the ROE 47 data above. Incidentally, Bill is always quick to say he appreciates these observations very much. With the WDS data base approaching something like 130,000 stars, the only way these kinds of errors get corrected is when visual observers note the discrepancies and report them to the WDS.

Click to enlarge the image.

Digging into the history of ROE 47, it appears the AB and AD pairs were discovered in 1895 by E.D. Roe, Jr., a British amateur astronomer, who used a six inch refractor. He added the “C” and “E” components in 1910, as shown in the excerpt at the right from a 1911 issue of the Astronomische Nachrichten.

I couldn’t find any biographical material on E.D. Roe, but it appears he must have had an astronomically dry sense of humor.   If you look at the top left hand corner of the image above, you’ll see he used the Greek symbol “ρ” as an identifier, which in Greek is pronounced rho, as in Roe.  Obviously he liked a good laugh.

Next trip – who knows. The winter rains are here and the few clear skies I’ve seen have had more dancing and twinkling stars than an out of control strobe light at an all-night dance party, meaning atrocious seeing, which is not usual for this time of the year. As soon as the weather cooperates (raining hard now with 60mph gusts of wind), I’ll see what I can find to grace the pages of this blog.

Until then, Clear and Cooperative Skies!   😎

Filed under: 4. Choose a Constellation:, Lacerta | 9 Comments »

OK — lace up those hiking shoes, throw your favorite snacks and a light lunch in a backpack, and don’t worry about water — we’ll have all the celestial nectar you could ever want right at our fingertips.  We’re going to step back in time and follow the meandering trail blazed by Sir John Herschel almost two hundred years ago through the zig-zagging confines of the Lacertan lizard.  I’ll carry the scope and eyepieces — and here, you hang on to this fifty pounds of mount and tripod. 😉

First, a few words about Sir John Frederick William Herschel, who was born into the distinctively famous shadow cast by his father, Sir William Herschel.  It didn’t take long, though, before he escaped into the bright light of fame on his own merits.  At the age of twenty-one he became a fellow of the Royal Society of London, based on his mathematical abilities.  Thirteen years later, in 1826, he was rewarded with the Gold Medal of the Royal Astronomical Society for his double star work with James South (those stars carry the prefix Sh or SHJ), a medal he won a second time ten years later.  He continued his astronomical research throughout the rest of his life, including several years of observations in South Africa, and also was involved in pioneering research in photography.  Seven of Saturn’s satellites, as well as four of Uranus’ moons, have names suggested by Sir John.

For this hike, we’re going to bring along Sir John’s notes on each of these stars.  It took some digging, but I finally found them buried deep in The Memoirs of the Royal Astronomical Society.  For anyone interested in all the details, I’ll add the particulars and links in the first comment which follows this post.

In the meantime, a few words about Lacerta might be a good idea, too — like where in blazes is it?

Welcome to the land of the lizard, which is the English translation of the Latin noun, Lacerta. Hardly a visually stunning constellation by any means, it makes up for it with a rich collection of double stars and open clusters. (Stellarium screen image with labels added, click for a larger view)

It’s another one of those dim constellations that seems to have been sketched out to fill space occupied by only faint stars — which, in fact, is exactly what happened when Johannes Hevelius sketched it into place in the heavens in 1687.  You’ll find it obscurely wedged between the west end of Pegasus and the southern edge of Cepheus, with the northern third of it parked comfortably in the Milky Way.  If you’re not under dark skies, you’ll no doubt find it much easier to locate with a pair of binoculars.

Or you can just follow me with that tripod down this trail in the dark.

Geez, I love the crunch of gravel under my feet in the starlight.

First stop — h 1746!

We’re going to start at the southern tip of this lizard-like configuration and work our way north. Get your bearings at 1 Lacertae first, then all you have to do is hop two degrees north to 4.65 magnitude h 1746. (Stellarium screen image again, labels added, click for a larger view)

h 1746 (All of the John Herschel stars are listed with the prefix HJ in the WDS)
HIP: 109754   SAO: 72155
RA: 22h 13.9m   Dec: +39° 42.9′
Magnitudes   AB: 4.7, 10.6      AC: 4.7, 12.1    AD: 4.7, 13.1
Separation:   AB: 30.4″             AC: 72.0″          AD: 195.2″
Position Angles:  AB: 188° (WDS 1999)   AC: 191° (WDS 1998)  AD:  71° (WDS 1998)
Distance: 563 Light Years
Stellar Classification: K3

OK, let’s set up that tripod — you still have it, don’t you? — at this scenic viewpoint just a bit north of One Lacertae.  We’ll drop the scope into place on it and point it north.  Ready?  Hit the RA switch, and — what?  YOU DIDN’T BRING THE BATTERY????

Never mind  …………  I’ve got the slow motion control knobs in my pocket.  Let’s slip them on and …….. there we go, we’re in business now.  I need a drink of nectar, though.

Ahhhhhhhhhhh …… much better.

OK, let’s point the scope north, and  —–  Wow!  Look at that primary!  That orange is spectacular!

“B” and “C” are weird, but “A” is wonderfully orange! (East & west reversed to match the refractor view, click for a view without this caption)

“B” and “C” seem to be a bit difficult, though, because they’re lined up in the same direction.  Now this is weird — even though “C” is 1.5 magnitudes fainter than “B”, it’s slightly easier to see.  What seems to make “B” a tough one is that it’s twice as close to the glare of the primary, and it even looks as if the glow from “C” may be affecting it.

Herschel’s experience of this one was different, though.  His observing notes on it state: “A third dist. 40″ nearly in line.”   He later measured that third star at 60″ and estimated its magnitude at thirteen.  However, I’ve noticed the magnitude estimates of this era tend to be one to two full magnitudes fainter than what are in use today.  So if you reduce his estimated thirteen by a full magnitude, and combine it with his later distance measurement of 60″, that pretty much describes “C”.  Obviously he had no problem in seeing it, but then he was using a twenty inch reflector, and ……….

I was using an Antares four inch f/14.3 refractor.   A few nights ago I thought I could see these two stars at times in an 18mm Radian (83x), but that was with averted vision.  I switched to a 14mm Radian (107x) and was able to catch a few fleeting glimpses of both “B” and “C” with direct vision, but I really needed a 10mm Radian (150x) to separate them completely.  What really caught me by surprise, though, was when I thought I could detect “C” in my f/16.7 60mm refractor with a 15mm TV Plössl (67x).  After I thought about it, I realized I was seeing the combined glow of both “B” and “C”, since I couldn’t distinguish them separately.  Had no luck at all, though, in seeing 13.1 magnitude “D” in the larger scope.

Shall we mosey on up the path, now?  I think I can see h 1786 twinkling way off in the distance, so let’s get a little closer.

The easiest way to get to h 1786 from our current location at h 1746 is to go due east four degrees to 8 Lacertae, which is located at the western tip of a triangle it forms with 12 and 10 Lacertae. In an 8×50 finder, you’ll notice 8 Lac is a stunning double. From there, turn back to the northwest and you’ll find h 1786 parked one degree away, right next to the slightly brighter 6.5 magnitude HIP 111355. (Stellarium screen image with labels added, click to enlarge)

h 1786           HIP: 111429      SAO: 52155
RA: 22h 34.5m   Dec: +40° 46.5′
Magnitudes: 7.0, 9.6
Separation:  43.4″
Position Angle: 225°  (WDS 2003)
Distance: 945 Light Years
Stellar Classification: A5

OK, we have to take a side trail now, and since it’s less used, we better pay attention in the dark or we’ll get lost up here.  Hey, look, there’s a junction at 6.2 magnitude HIP 110849 with a sign that points to 5.9 magnitude HIP 111259.  Let’s follow it for a ways and ……….  well, look at that, the trail ends here!  But I think we’re in luck — here’s a knoll we can set up on that has a clear view to the east and north.

Now if you look due east, you’ll see something that’s certain to electrify your erfle.  That pair of white stars over there is 8 Lacertae — actually, if I remember correctly, there are five stars in that system — but the first time I cast eyes on the two white ones, it really made my Plössls palpitate.  Greg wrote it up here, so you might take a peek at that for a moment.  Meanwhile, I’ll point the scope to the northeast and get h 1786 centered in the eyepiece.

There, that’s better.  Take a look.

A slight tinge of primary blue in a faint field, with a bonus — ES 1697 — to the west. (East & west reversed, click to lose this caption)

Now the thing I like about this pair of stars is that slight tinge of blue in the primary, which helps draw your eye to this faint field.   Well, most of the field is faint — you’ll notice 6.7 magnitude HD 213835 about halfway across the field to the west, and if you look carefully, just before you reach it, there are two faint stars parked very closely together.  Those are ES 1697, magnitudes of 10.0 and 10.7, separated by 2.9 seconds of arc.  The Washington Double Star Catalog (WDS) shows the position angle at 340 degrees, but that observation was made in 2001, and it looks to me like the measurement might be out of date since the secondary is at almost exactly the same angle as that of h 1786.  At any rate, it was discovered in 1917 by Thomas Henry Espinall Compton Espin (1858-1934) — known as T. E. Espin to his friends — a British observer who discovered over 2500 double stars using seventeen and twenty-four inch Calver reflectors.  (That information comes from the Webb Society Deep-Sky Observer’s Handbook: Volume 1, Double Stars: 1986, p. 70)

I had an f/16.7 60mm refractor out here last week pointing at h 1786, and it actually served up a very neat, crisp view in a 20mm TV Plössl (50x).  And of course, it was a pleasant sight in the 105mm f/14.3 refractor, especially with the wider view I had in a wonderful old 26mm Celestron Plössl (58x) that I used to make the sketch.

Herschel estimated the magnitudes of these two stars at “8-9” and “11” — again, fainter by a couple of magnitudes than current measurements.  For a position angle, he came up with 228 degrees — close to the 2003 WDS measurement of 225 degrees — and for their separation, he ended up with 30 seconds of arc, a bit tighter than the 43.4″ shown by WDS.

OK, time to move on to h 1735, so let’s turn around and follow the trail back to h 1746.

To get to h 1735, you can either go back to h 1746 and move about three degrees northeast to 6 Lacertae, or you can just hop two degrees northwest to 6 Lac from h 1786. Once you’re at 6 Lacertae, another northwest hop of four degrees will get you to 2 Lacertae. From there, leap two degrees to the west while leaning to the south to reach 5.5 magnitude HIP 109745. Continue in that direction another degree and you’ll come down at h 1735. (Stellarium screen image, labels added, click to enlarge)

h 1735          HIP: 109354    SAO: 51698
RA: 22h 09.3m   Dec: +44° 51′
Magnitudes     AB: 6.7, 9.7          AC: 6.7, 13.5     AD: 6.7, 6.8
Separation      AB: 27.3″              AC: 43.0″            AD: 109.0″
Position Angles    AB: 109°        AC: 138°             AD: 286°      (All WDS 2006)
Distance: 652 Light Years
Spectral Classification:  B9

Hey, look!  Here’s another side trail, and the map shows it leads to 6 Lacertae.  Let’s take a stroll down it.  Duck, though, there’s a lot of stardust clinging to these old tree limbs — looks like no one has used this trail for a while.  Watch out for those luminescent slithering lizards, too.

Ah, here we go — the blue-white beauty of 4.5 magnitude 6 Lacertae already — boy, that was a quick little detour!  Might want to shield your eyes from the glow so you can see this trail in the dark.  Now, let’s wander on up this well-worn path to 2 Lacertae, another 4.5 magnitude blue-white dazzler, and set up at the junction to HIP 109745.  Wow, what a night — look at the Milky Way glowing in the dark up there to the north!

Ease the tripod down again — here’s the scope — and let’s point it southwest — yep, right there, just past HIP 109745.

“B” has just a slight eye-catching touch of blue, and “A” and “D” are unmistakably white. (East & west reversed, click for a caption-less view)

This one you can easily split in an 8×50 finder — what you see there is “A” and “D” — which helps to locate it.  I haven’t been able to wriggle “C” loose from the glow of its brighter companions — it’s too darn faint at a magnitude of 13.5 — but the other three stars offer such a beautiful sight that I haven’t really missed it.

Herschel apparently didn’t consider “D” to be part of this system, at least at the time of his initial look at them.  He describes three stars with magnitudes of “7-8”, “9-10”, and “15.”  He may have gone back and made a later observation, though, but I haven’t found it yet.

You can see that “A” and “D” are a definite white, and “B” has just a slight eye-catching touch of blue in it.  This is an interesting multiple star, not only because of the way the three visible components are lined up, but because “D” is just a tenth of a magnitude fainter than the primary.  But “B” is obvious, too — I picked it out with no problem last week in the 60mm f/13.3 Lafayette refractor I have mounted on my AR-5.  It was a breeze in a 20mm TV Plössl at 40x.

Speaking of breezes, it’s getting a bit cool up here.  Better head on up the trail — we can warm up on the zigzagging switchbacks between here and h 1741.

To get to h 1741, start at 2 Lacertae, move two degrees east to 5 Lacertae, two degrees north to 4 Lacertae, bend slightly to the northwest and continue for a bit more than two degrees to reach h 1741. You can see that it and 4 Lacertae form a triangle with Beta (β) Lacerate, which also helps to locate it. (Stellarium screen image with labels added, click to enlarge)

h 1741        HIP: 109521    SAO: 34143
RA: 22h 11.2m   Dec: +50° 49′
Magnitudes     AB: 5.4, 10.4    AC: 5.4, ???   AD: 5.4, 10.0
Separation      AB: 36.0″           AC: 62.1″        AD: 73.6″
Position Angle   AB: 286°      AC: 271°      AD: 271°   (C:  WDS 2000, A & B:  WDS 2008)
Distance: 179 Light Years
Spectral Classification: All A5

OK, here we go, let’s zig to 5 Lacertae, then zag to 4 Lacertae, and set up the tripod and the scope again.  We’ll peer across the valley and peek at h 1741.

All white, but not alright ….. “C” is hiding somewhere in the shadows. (East & west reversed again, click to lose this caption)

Now, this one is all white — all white, but not alright.  That’s because the mysterious “C” star — the one in the data line above with question marks for a magnitude — seems to project a shadowy presence.  It’s in a very inconvenient spot for detection — lined up in the same position angle as “D”, and only 11.5 seconds of arc from it — and not knowing it’s magnitude, I can only guess that it’s at least less than “D’s” 10.0 magnitude.  At any rate, it seems to be causing some elongation in “D”.  I’ve tried to pry these two apart several times, but haven’t had any luck in getting any more than that elongated form.  According to the WDS, “D” was added in 1902, and the elusive “C” came later, in 1923.

But ….. Herschel’s notes state he saw another pair of stars, in addition to “B”:  “Two more precede.  Nearest 12m; farthest 10m.”  I’m not sure what the “m” in those distances mean, but they do indicate a closely separated pair of stars, and his “precede” puts them on the west — which is the correct — side of the primary.  So it looks like he saw both of them.

At any rate, this gem of Sir John’s stands out well from the sparsely dim field it calls home.  Actually, the field is really fairly dense, but it’s the dimness of the stars that make it appear sparse.  There are a lot of interesting patterns to be seen in all those tenth, eleventh, and twelfth magnitude field stars, though.  As I made the sketch shown here, I found myself getting lost as I followed their meandering paths right on out of the field of view shown in the sketch.  That wasn’t particularly hard to do, since I was using an undriven mount — I just let them drift and went along with them, until I felt a tug from the primary and got pulled back to the center of the field.

Ready for the last leg of this hike along the Lacertaen Trail?  Let’s wander on up to Beta (β) now.

The easiest way to approach h 1791 is from Delta (δ) Cephei, another stunning double. You’ll find that h 1791 is located about a degree and a half to the south, nestled between 5.1 magnitude HIP 111795 and 5.7 magnitude HIP 111362. (Stellarium screen image with labels added, click for a larger view)

h 1791         HIP: ?????       SAO 34602
RA: 22 35.7m   Dec: +56° 52′
Magnitudes        AB: 7.7, 9.7     AC: 7.7, 11.0
Separation         AB: 17.2″         AC: 89.6″
Position Angle   AB: 59°            AC: 141°     (Both WDS 2006)
Distance: ?????
Spectral Classification:  G0

Beta (β) is an easy hike of about two and a half degrees due north along another well-worn trail, so let’s huff and puff our way uphill for a ways.  Here we go  …..  man, I’m glad we’re near the end of this little hike, my feet are getting sore — how about yours?  One more bend in the trail up here, and  ………  uh oh  ……….  looks like we’ve got a problem  …………  we’re at the end of the Lacertaen trail ……….. .

But look, there’s a bench someone was thoughtful enough to put here.  Let’s have a seat, rest our feet, and take a long sip of that luscious stellar nectar that’s bubbling up out of this Milky Way spring.  Here’s a cup, just scoop some out of the air there, and ……. mmmmm, mmmmm — man, that’s good stuff!

Now, we could wander off and find a connecting trail that would take us to Delta (δ) Cephei in a couple of light years, or we could just stare across this dazzling pool of stars gleaming in the Milky Way until we find h 1791.  I vote for the last idea, especially since the nectar is beginning to make my legs weak.  Isn’t that good stuff?  What?  Yeah, I hadn’t thought of that — Nectar of the Gods it is!

Let’s aim the scope across to the northeast, get 5.7 magnitude HIP 111362 in sight, and then nudge it to the east and h 1791 will slide into our eyepiece.   And hey, look over there —– that magnificent star in the background is the delectable Delta (δ) Cephei — mouth-watering, isn’t it?  I love the contrasting yellow-orange and blue of that pair — gotta come back to that one.

Anyway, here we go — and there it is!  Wow!  Even though it’s a bit dim, this is beautiful.

A bit dim, a bit beautiful, a bit compact …….. even a bit like Delta (δ) Cephei. (East & west reversed, click … to … lose this caption)

It’s a compact object that stands out in a very full field of 11th and 12th magnitude stars.  It’s helped quite a bit by its colors.  The primary is a pale gold, and “B” is a distinctive bluish-white — kind of a weak imitation of Delta (δ) Cephei, now that I thing about it.  And “C” — well, “C” is just out there to be seen, floating off in the distance far enough away that it looks like it might wander off some day — or night.

When Herschel looked at this one, he estimated the magnitudes of “A” and “B” at eight and nine.  The separation and position angles he came up with are very close to the 2006 WDS data: sixteen arcseconds and sixty-four degrees — but he didn’t include “C” at all in his notes, although it’s likely he saw it.

There are so many stars in this field of view that when I made the sketch shown here, I resorted to using an 11mm TV Plössl to narrow the field to a more manageable level.  But with a wider field of view — I used an 18mm Radian (66x) last week in the AR-5 — I was able to pull the much brighter HIP pair, 111362 (magnitude 5.7) and 111795 (magnitude 5.1), into the view.  They tend to overwhelm the background, though, so I lost them again by narrowing the field with a 24mm Brandon (49x), which also brought out quite a bit of background nebulosity.  Kind of eerie, actually.

And then there’s that line of tenth and eleventh magnitude stars trailing off to the southeast and ending in a triangle, which is really very intriguing.  Kind of tempting to just follow them and see where they lead.

But we’ve covered quite a few light years tonight, so why don’t we just stay put for a while.  The view is simply superb, my feet need a break, and this nectarius elixir is exhilarating  ——- so I think I’ll just sit here and let all of this sink in until it fades into the weak light of dawn.  Stick around — the rest of the night is a feast just waiting for our eyes to inhale it.

Filed under: 4. Choose a Constellation:, Lacerta | 1 Comment »