601 replies to this topic

[Fiske]

Confession: I had intended for a few of these posts to be PMs. (I'll let you draw your own conclusions about which.) Hopefully, I have not offended anyone.

 

For clarification, I do not categorize myself as "woke" but I at least understand what the word is supposed to mean. 

[clastro8*]

Hi, Fiske, the Stf 33 is listed in the AL doubles list as: upper case sigma I33, RA 17 03 7, Dec 13 36, mags 5.9, 6.2, and 8.5, seps 305 and 231, PA's 117 and 11.

 

Also, thanks for the abbreviated Cygnus doubles list, I had started my own as a simplified version and was pleased to see the entries appear on that version too.

 

Last night, I was all set to beginning finding them only to find thick clouds everywhere, alas.

[Fiske]

https://www.wikihero...le#Designations  

 

[Fiske]

OK, this is a REALLY tough challenge. Not for seeing the doubles, those are ridiculously easy to see especially at 20x with 20.5 mpsas sky. No, the problem is that there are way too many stars in Cygnus! OMG! It makes hopping really difficult. Spent most of my time just double checking I am looking at the right star because the sky shows so many more stars than the map!

Given the terrible problem of having near 21 mpsas skies in your backyard , making it difficult to pick out Cygni 100 Challenge doubles from the clutter of 12th magnitude background stars , I wonder if it wouldn't be easier to locate them with the 20x65ED.

 

You might even consider masking it to 50mm...

 

 

(But seriously, it seems like a nice job for the 20x65ED.)

[jrazz]

I am using the 20x65 for this…

[Fiske]

Oh...

[Fiske]

I received a prompt reply from the US Naval Observatory regarding the stelledoppie data problem affecting the double star GUI 25AC, mentioned above. Details from the Naval Observatory are provided in this Double Star forum post. 

 

The Washington Double Star Catalog page on the Naval Observatory website includes a lot of fun stuff for observers. Definitely worth a visit. 

Edited by Fiske, 01 August 2022 - 01:08 PM.

[aznuge]

^^Maybe a note to Stelle Doppie?

[aznuge]

Hi, Ray. I looked at the listing for the Astronomial League Asterism Program, but did not find 60 Hercules included. Are you referring to another list?

 

I think he is referring to this book (AFST&B):

 

[Fiske]

Thanks, Nuge. You're undoubtedly correct.

 

Unfortunately the book is out of print and no copies appear to be available used. Moreover, it looks to be self-published, so it's not likely that many copies were printed in the first place. It's too bad it wasn't published online one way or another. That approach would have enabled many more observers to use it.

 

While doing a web search for that, I did come across this online guide, which is well done. But doesn't include the Hercules 60 asterism. 

 

https://deepsky.waar...s_EN_VER4.2.pdf

[aznuge]

...

 

While doing a web search for that, I did come across this online guide, which is well done. But doesn't include the Hercules 60 asterism. 

 

https://deepsky.waar...s_EN_VER4.2.pdf

I have used that one quite a bit.  It's a good supplement to the AL guide and has added value for the asterism hunter imo.

[jrazz]

I am 1/3 of the way through the Cygnus 100 challenge. 

 

Wow... This is definitely difficult. Looked through some 8" and 9" doubles tonight (SAO48866, SAO49431, and STT 416 AB).  All I can say is thank heavens for dark skies. I think I can see up to mag 11 right now with my 20x65ED (ok, fine, maybe 10.5) but for these close ones it really takes a lot stability and concentration. You look at something you know is the right double, stare at it, and it slowly resolves.

 

This is fun!

[Fiske]

Well done on the Cygni 100 Challenge, Jordan. 

 

Of course, the weather has been miserable here since I made that announcement.  But I am hoping to make a start this evening. I have been annotating my Uranometria, and also finding annotations from years previous, so some of the doubles on the challenge list are already in my journals, though I plan to make fresh observations of the full 100. Also working with Sky Safari. Unfortunately, I have the Android version and have so far not been able to get the skylist import feature to work. I have to say, the app has a variety of bugs and problems. 

[aznuge]

Intending to spend some time in Hercules last night, I initially mounted and aligned the Pinty laser finder that was recommended here.  I used Polaris, out of convenience, to align the green laser to the FOV in the OB127s.  To begin with the alignment was way low and to the left, and I wondered if I would run out of adjustment travel, but there was plenty to dial it in, and that's all it took.  Once centered in the BTs FOV, the beam remained there through-out the session.  Very solid unit, just what I need for my style of star hopping with BTs.  Amazing that something this good is so inexpensive.  I like the on/off push button on the end of the laser sight and used it as opposed to the optional extension cord switch.

 

Moving over to Hercules, which was pretty much at Zenith, I began my observing with the globular cluster M13.  I was using Pentax XW 10mm eyepieces, with an effective power of 65x in this BT.  Once in view, M13 was glorious.  I could see some elements of individual star structure, especially with averted vision.  Globular clusters are in a special category of binocular delicacies for me.  M13 tonight, with my particular 65x BT view, shone brightly, and was very satisfying.  However, M13 can be seen with the naked eye under the right conditions - just not for me.  This night was not the best for seeing, with thin clouds and moon glow.  Discovered in 1714, Edmund Halley said in so many words that with the naked eye it is a little patch of light that can be seen when the skies are "serene" and when there is no moon. 50 years later, Charles Messier was to catalog it as "not a comet", and it has become known as Messier 13, or as some call it, the Great Hercules Globular Cluster.

 

Over on the opposite side of the keystone in an area I call the left thigh of Hercules (based on constellation art), lies a group of three stars that I was interested in exploring - Pi, 69, and Rho Herculis. My attention quickly centered on Rho Herculis.  In my field of view, with Rho centered, I saw a symmetry of stars on either side, in somewhat the shape of a flattened octagon, with Rho at the bottom center in my FOV.  As I viewed this structure and tried to see a shape in it, I noticed the Rho was actually two stars, tight together and aligned toward the north east.  One star appeared yellow/white and the other gray or bluish.  They were about the same magnitude.  Excited about these twins I decided to take an intermission, to check on this unexpected double and to see if any others were nearby.  Back at the BTs, I began to explore what I had found from Stellarium and Stelle Doppe - STF 2161 AB and STT329.

 

STF 2161 AB

Coordinates: 17 23 41, +37 08 45

Separation, PA: 4.1", 321degrees

Magnitudes: 4.50, 5.40

A serendipitous encounter, this double was engrossing, and led me to post about it in this double star thread.  I was quite happy to discover that the separation was 4.1" since it was so cleanly split in the Pentax 10mm eyepieces.  The direction was almost perfectly NE, with the slight magnitude difference between the primary and 2nd now visible.  As far as coloring goes, to my eyes the primary was more toward yellow and white, whereas its companion was appeared to be tinted blue.  This double dominates the field of view with its combined magnitude, and together with the pattern of surrounding stars in the view, left me wanting to assign an asterism type shape to it, but none were forth coming except "squashed octagon".  It was interesting enough to make a diagram or rendering of it.

 

STT 329

Coordinates: 17245, +3657

Separation, PA: 33.5", 12 degrees

Magnitudes: 6.35, 9.88

Up and slightly to the left in the same filed of view as Rho Herculis, there was supposed to be another double star.  I hadn't really noticed it in the first observation.  But after the intermission I knew where to look.  I wasn't the least bit disappointed.  STT 329 is a completely different type of double star from the previous one.  The first contrast is that the separation was much greater - 33.5" compared to 4.1.  Then there was the huge magnitude delta of 3.5, four times greater than the one above.  What is there about a big mag contrast the makes the secondary star appear mysterious or even majestic?  Maybe its just me, but when I saw HD 157910B within the glow of its primary star, it riveted my view for quite awhile.  It was distinct and easy to see at almost magnitude 10.  Then when going back to this double, it would grab my attention even before the primary would.  This is somewhat reminiscent of the Polaris and Mintaka doubles in my memory.  Anyway, this double is a fun one to observe, especially in the context of the Rho Herculis double, and the associated stars in this FOV.  As I remember it, the colors of the stars in this double were white/yellow for the primary and gray-yellow-orange for the companion.  For me, dim stars tend to go more towards gray, and are difficult to extract color.  Overall this was a very pleasing double to view, and another BT opportunity not intentionally targeted.

 

To top off the session I wanted to take in M92 before leaving the scene.  I pointed the BTs and Pinty laser in the general direction of M92, about 5 degrees north of Pi Herculis.  Then using 12x42s with one hand and moving the BTs and laser beam with the other, I got convergence of the green beam, 12x42 FOV and the globular cluster.  Trifecta achieved! Did I mention that I really like this laser sight?  M92 appeared as a cold, lonely, gray cotton ball in a sea of darkness.  But it still held its own as a globular cluster delicacy.  I could not see any detail within the cluster as I did with M13, but it was still engaging to observe.  M92 is not as easy to see with the naked eye as M13 - for those that have dark skies of course.  It was discovered in 1777 and initially described as a nebula.  Charles Messier rediscovered it in December of 1781, and during the same evening also catalogued M84-M91.  What a night that must have been!

 

This is long, so thanks for reading!

 

Clear skies everyone, or a gap in the clouds when you need one

 

   

Edited by aznuge, 06 August 2022 - 09:49 PM.

[jrazz]

Wonderful report!  

 

Isn't that GLP just awesome? I can't imagine using my 100XL without it today.

 

One thing though, if you ever decide to use it with the momentary switch, make sure you have a cover for the front and put it on as soon as you are done! I've almost blinded myself before wizening up and printing a cover. It's convenient but when you lift the binocular out it's easy to press.

[aznuge]

Thanks, Jordan. You are good to go in the advice department, will keep that in mind.

[Fiske]

I've discovered that the Cygni 100 Challenge list includes two double stars which may be imposters.  I have been manually building a Sky Safari Observing list for the full 100, because for whatever reason the SkyList import feature is not working on my Android tablet. I will say that as helpful as it is, Sky Safari has more than its fair share of bugs.   And anyway, manually adding the entries to an observing list isn't onerous and has the benefit of helping me understand their positions around the constellation, what might be near by in the star field, and etc.

 

Here is what the constellation looks like with the list highlights turned on.  It's not quite so scary when you zoom in. Plus, the list includes a few extras -- doubles that missed the cutoff for one reason or another but are still fun. A couple of which may get promoted to the 100 list as explained below. 

 

 

I noticed that the CAN 20AC and CAN 40AE entries do not include SAO data and was trying to identify them visually in Sky Safari based on position and found nothing matching the magnitude of the stars anywhere near the indicated positions. I cross referenced the positions using simbad via the stelledoppie page to double check the Sky Safari map, but did not find anything, so I am supposing there may be a problem with the data for these two systems.

 

CAN 20AC

20h34m +40*51'

6.90/8.60 13.8" pa 330

 

CAN 40AE

20h32m +41*26'

7.70/9.00 7.8" pa 25

 

Here is an image from simbad showing the position of CAN 20. For reference purpose, the blue white star east (left) of SAO 49823 (which is SAO 196503) is 7.90 magnitude, the same magnituded supposedly as the primary of CAN 20. A much fainter double star can be seen in the correct position. The primary would appear to be TYC 3157-0581-1, which is 11.16 magnitude. 

 

 

Here is a second simbad image showing the positions of both CAN 20 and 40. There isn't anything resembling a double star at the position indicated for CAN 40. Certainly nothing near 7.70 magnitude. 

 

 

I cross-checked the primary WDS data this time , confirming the positions indicated in stelledoppie and they concur. So, an inquiry about the two double stars has been sent to the US Naval Observatory. I will share the reply in a subsequent post here. I suspect the end result of this will be the removal of these two doubles and the promotion of a few that didn't quite make the cutoff.

 

BTW, here is an exported SkyList that you might have more luck importing than I did, if you use Sky Safari.

Attached Files

•  Cygni 100 Challenge.skylist   25.49KB   14 downloads

Edited by Fiske, 13 August 2022 - 07:31 PM.

[jrazz]

I saw these and figured I won't dwell on them. I'll get back to them in the end once I figure out exactly where they are. At this point I'm roughly halfway through the challenge.

[Fiske]

I saw these and figured I won't dwell on them. I'll get back to them in the end once I figure out exactly where they are. At this point I'm roughly halfway through the challenge.

Nice work, Jordan! 

 

You're way ahead of me on the challenge list, though I am having a great time making observations and am planning to share some of those here soon.

 

I'll follow up on CAN 20 and 40 when more information is available, plus will list the replacement candidates. 

[Masonry00]

I've discovered that the Cygni 100 Challenge list includes two double stars which may be imposters.  I have been manually building a Sky Safari Observing list for the full 100, because for whatever reason the SkyList import feature is not working on my Android tablet. I will say that as helpful as it is, Sky Safari has more than its fair share of bugs.   And anyway, manually adding the entries to an observing list isn't onerous and has the benefit of helping me understand their positions around the constellation, what might be near by in the star field, and etc.

 

 

 

I noticed that the CAN 20AC and CAN 40AE entries do not include SAO data and was trying to identify them visually in Sky Safari based on position and found nothing matching the magnitude of the stars anywhere near the indicated positions. I cross referenced the positions using simbad via the stelledoppie page to double check the Sky Safari map, but did not find anything, so I am supposing there may be a problem with the data for these two systems.

 

CAN 20AC

20h34m +40*51'

6.90/8.60 13.8" pa 330

 

CAN 40AE

20h32m +41*26'

7.70/9.00 7.8" pa 25

 

 

I cross-checked the primary WDS data this time , confirming the positions indicated in stelledoppie and they concur. So, an inquiry about the two double stars has been sent to the US Naval Observatory. I will share the reply in a subsequent post here. I suspect the end result of this will be the removal of these two doubles and the promotion of a few that didn't quite make the cutoff.

 

BTW, here is an exported SkyList that you might have more luck importing than I did, if you use Sky Safari.

I don't know anything about the origin or history of the Signi 100 Challenge List but is it possible the two imposters were inserted on purpose to keep people honest?

Edited by Masonry00, 13 August 2022 - 11:21 PM.

[Fiske]

I don't know anything about the origin or history of the Cygni 100 Challenge List but is it possible the two imposters were inserted on purpose to keep people honest?

Well I know a little bit about the history of it, Masonry. 

 

I created it a few weeks ago using the StelleDoppie advanced search feature, with the data shown in this screenshot, which returned this list of 100 double stars. 

 

 

StelleDoppie is a great resource to create double star lists customized to your preferences.

 

The imposters where among the results returned. I previously found a problem with some Cygnus double star listings reported by stelledoppie as being in the constellation Hydra. I checked with the US Naval Observatory about this, and it was pointed out that their constellation cross-reference is correct, and the problem is in stelledoppie. It presumably occurred during data import somehow. It is not always the case that the USNO cross-reference is correct, BTW, because an algorhythm is used to make constellation assignments for double stars and stars close to constellation boundaries are sometimes assigned to the wrong constellation. When problems like that are found, the constellation assignment is updated manually. (This was explained by the USNO astronomer who replied to my email, Rachel Matson.)

 

Rather than relying on the stelledoppie data, I checked the Washington Double Star catalog maintained by the USNO and found that the data for CAN 20 and 40 included in that matches what is in stelledoppie, so it seems like there might actually be a problem with the data. A USNO astronomer will probably reply to the email I sent about this either explaining why the data is not anomalous, or that additional research will be done regarding the doubles in question. Here is a link to the WDS 18-23 hour section where the two doubles are listed. The CAN discoverer code is for Saida Caballero-Nieves, an astronomer who is (or at least was) an Assistant Professor at Florida Tech. The data appears to be from a 2014 study that included designations up to CAN 40. A key to discoverer codes can be found on the USNO web page.

Edited by Fiske, 14 August 2022 - 10:19 PM.

[Fiske]

Given the long list of contributors for the CAN study, I'm guessing what it actually represents is a project led by Cabarello-Nieves consisting of work from a number of grad students. Data anomolies in a project like that are not uncommon, I would guess. That's not to criticize the overall accuracy of the data provided, but it is unlikely the professor would have sufficient time to carefully review and confirm the findings from each contributor.

[fred1871]

The entries for CAN 20 and CAN 40 have the letter 'K' in the notes column.

That indicates these are infra-red objects, with IR magnitudes given instead of V (visual) magnitudes.

 

The visual magnitudes could well be very much fainter in such cases, hence the stars not showing up at the expected level of brightness. This appears to be what has happened here. Note that CAN 40 has an entry only for 2008 observations. On the numbers, if the magnitudes were visual, it would have been discovered long ago.

 

The K objects are a potential trap; if they're read as the usual V magnitude entries you'll often find yourself hunting for something that won't fit the expected description, because in visual terms that is not there.

[Fiske]

Thank you, Fred!

 

  

[Fiske]