601 replies to this topic

[Fiske]

^^ The SHY sky seems intriguing...

I find it so. 

[Fiske]

Here are a few pleasing doubles in (and near) Draco that I have observed in the past week or so. 

 

STF 2420 / Omicron Draconis

18h51m +59*23'

4.77/8.26 sep 37.6" PA 316*

Optical double star

 

Deep yellow primary with a delicate blue secondary. Sensational with the Nikon 18x70 IF WF.

 

STF 2273

17h59m +64*09'
7.31/7.63 sep 21.4" pa 282*

Physical double star

 

Not far from the Cat's Eye planetary nebula (NGC 6543). Evenly matched bright white stars, close but not tight with the 18x70. In a "?" asterism and a gorgeous starfield. Another sensational binocular double star. 

 

STF 2277

18h03m +48*28'

6.25/8.93 sep 26.8" pa 129*

Optical double star

 

The double is in Hercules but easily found as the point of a narrow triangle, the base formed by Eltanin (one of the stars of Draco's head) and 30 Draconis. STF 2277 is a little more than 3 degrees to the southeast from Eltanin/30 Dra. The primary is brilliant white and the secondary is much fainter and a distinct reddish-brown. In an asterism that looks like a boat anchor. Observed with the Nikon 18x70.

 

Iota Herculis is a brilliant white star that forms a triangle south of Eltanin and Rastaban in Draconis. At 3.8 magnitude it can be seen naked eye from suburban skies. An easy way to locate the globular cluster M 92 is to make a shallow arc to the southwest starting at Eltanin and continuing through Iota Herculis, which is about 3/5s of the distance to M 92 itself. The star fields in the northeast corner of Herculis are bright and lively, well worth lingering over.

Edited by Fiske, 25 June 2023 - 09:41 PM.

[Sarkikos]

Here is a taste of what is possible.  I split 132 doubles holding the Canon 10x42 IS binoculars in my left hand and SkySafari Pro on iPhone in the right.  I was seated the entire time, so that helped. 

 

Mike

Attached Files

•  Canon 10x42 IS Double Star List.pdf   202.2KB   31 downloads

Edited by Sarkikos, 26 June 2023 - 08:26 AM.

[Fiske]

My approach is more like this. 

 

[Fiske]

There is a tablet with Sky Safari hanging around somewhere. 

 

Might be outside of the frame on my (celestial) music stand...

 

 

 

Update: Hmmmm. The celestial music stand is in the image. So the tablet is probably on one of the light shield shelving units. Anyway, it's there somewhere. I never observe without. 

Edited by Fiske, 27 June 2023 - 06:47 AM.

[Fiske]

Here are some observations I made Sunday 25 June 2023, after enjoying a pleasing view of M 57 with the 120XL+SD+20XWs (33.5x / 2.09 degree FOV). It was a wonderfully pleasant evening with a transparent sky.

 

This SkySafari chart of the starfield around Sheliak shows double stars from a highlighted skylist. The list, attached below, includes doubles north of -30 00 00 declination, with primary and secondary components brighter than 9.5 magnitude, and separations between 4 and 500 arc-seconds. The list includes 1948 double stars.

 

 

STFA 39 / Sheliak
18h50m +33*22'
3.63/6.69 sep 45.7" pa 149*
Distance: 960 LY
Spectral type:  B8.5Ib-II C / B7V C
Color Index: +0.00 white  / -0.08 blue-white

 

Glorious with the 120XL+20XWs (33.5x) Brilliant light yellow primary with a diminutive neon blue secondary at a comfortable distance. A sprinkling of faint stars hovering about – maybe also part of the system? Colors readily seen with Nikon 18x70 IF WF.

 

STT 525 / HR 7140

18h54m +33*58'
AC 6.14/7.60 sep 45.4" pa 350*
Physical double star
Distance: 1482.13 LY
Spectral Type: G5III+A8 / A E
Color Index: +0.93 yellow-orange / -0.06 blue-white

 

Yellow primary with blue secondary. Generously spaced. A fine bright pair. Obvious magnitude difference.

 

STF 2421 / HD 175885

18h56m +33*47'
8.13/9.34 sep 24.6" pa 57*
Optical double star
Distance: 1180.40 LY
Spectral Type: B9V D / ??
Color Index:

 

Quite near STT 525 but the secondary is faint so it is easy to overlook and sweep past. Have I noticed this double before? Brilliant white primary with a tan secondary, close but not tight. Nikon 18x70.

 

Here is a simbad image of the three doubles northwest of Sheliak, in a charming starfield.

 

 

 

STF 2372
18h42m +34*45'
6.45/7.73 sep 25" pa 82*
Optical double star
Distance: 1489 light years
Spectral type: B5V / A0
Color Index: -0.11 blue-white / -0.05 blue-white

 

A cozy pair of bright white and pale blue stars. A fine double at the end of a stream of stars leading away from Sheliak. Midway along the stream, on either side, are two additional doubles.

 

STTA 172
18h44m +34*00'
7.91/8.66 sep 64.9" pa 5*
Physical double star
Distance: 178.5 light years
Spectral type: F8 / F8
Color index: +0.50 yellow / +0.65 yellow

 

Warm white primary with sand colored secondary, generously spaced.

 

STF 2390

18h45m +34*31'
7.37/8.56 4.3" pa 155*
Nature uncertain
Distance: 1164.99 light years
Spectral type: A5 / ??
Color Index: +0.21 yellow-white / ??

 

Could see it as two stars in contact at 33.5x with the 20XWs. Needed the 10 XWs (67x) to resolve. Challenging even at 67x. Too close to get colors.

 

An enjoyable trio of double stars in a lovely field.

 

Here is another SkySafari image of the entire constellation with the skylist doubles highlighted.

 

 

The benefit of having a skylist like this is that any evening it is easy to view a handful of doubles, combining them with some deep sky objects, maybe a few carbon stars or a variable star (like Sheliak ) and one has a full observing program. Note: at 512k the file was too large to attach to this post, so it has been compressed as a zip file.

Attached Files

•  Doubles_Brighter_Than_9.5_Between_4and500_sep.zip   87.99KB   15 downloads

Edited by Fiske, 03 July 2023 - 10:36 PM.

[jrazz]

Awesome!
Yrs, I’ll take a look at 2390 fo shu!

[Fiske]

A prime 34x80 candidate. 

[jrazz]

You know what? You're right!! 34x80 is perfect!

 

I haven't been using it because I stole one of the weights for the CGEM. I have the replacement coming this week....

[jrazz]

Your idea of exporting from Stelladoppie to SkySafari is AWESOME!

 

I can't believe I'm just learning (or remebering) it now! 

 

 

I exported some interesting lists to my phone and will observe them in the next couple of days. I have a 0.8"..4" list for the TOA and BT-100XL as well as a 4"..7" list for the 34x80

 

 

 

This is just awesome and I'm really happy!

[Fiske]

I have the Sky Safari 7 pro version now. It cost $29. Something like that. A tremendous value given the functionality provided. I consider it to be an indispensable observing aid. The amount of information available at your fingertips is remarkable. 

Edited by Fiske, 04 July 2023 - 09:42 AM.

[jrazz]

I have the Plus but I'm not sure the difference to Pro is that much of an advantage...

 

Though as much as I use it I really should!

[Dale Smith]

I have the Plus as well and like Jordan, wasn't sure there was that much of an edge to Pro, but maybe I should reconsider. I also haven't used StellaDoppie, but I can see that being able to export from that to Sky Safari is huge. Thanks!

[jrazz]

Ugh!

 

 

 

I broke down and got the Pro. There's more stars and there's labels for the moon.

I completely agree with Fiske. For the use I get out of it it's totally worth it! (one of my most used apps)

[Fiske]

When you consider the price of a three volume Uranometria 2000 set, or a laminated field edition of the Sky Atlas 2000 (plus the Sky Atlas 2000 guid), versus all of the functionality and information delivered by that app on a tablet, it's a remarkable value. Just think about the price of a single eyepiece. 

[Sarkikos]

Ugh!

 

 

 

I broke down and got the Pro. There's more stars and there's labels for the moon.

I completely agree with Fiske. For the use I get out of it it's totally worth it! (one of my most used apps)

Most apps for smart phones and tablets are pretty inexpensive, compared to how much programs could cost for desktop computers in the "old" days.  I don't see not getting SkySafari Pro.  It doesn't make sense to quibble over the small cost of the full app.  

 

Mike

Edited by Sarkikos, 04 July 2023 - 03:42 PM.

[Fiske]

Most apps for smart phones and tablets are pretty inexpensive, compared to how much programs could cost for desktop computers in the "old" days.  I don't see not getting SkySafari Pro.  It doesn't make sense to quibble over the small cost of the full app.  

 

Mike

  

 

Exactly. Licenses for destop apps like PageMaker, PhotoShop, CAD applications, etc. cost hundreds of dollars. Mobile apps are far less expensive. Less than the price of a single astronomy book, even.

Edited by Fiske, 04 July 2023 - 03:51 PM.

[Sarkikos]

I'm using SkySafari Pro on an iPhone 13 now.  Looks like if I'm going to start getting more serious about double stars, I'll have to get a device with a larger screen.  These skylists with several hundreds - even a 1000 or more objects - are seriously cluttered on the small screen of an iPhone.  Time to shop for a 12" tablet. 

 

Mike

Edited by Sarkikos, 04 July 2023 - 03:58 PM.

[jrazz]

  

 

Exactly. Licenses for destop apps like PageMaker, PhotoShop, CAD applications, etc. cost hundreds of dollars. Mobile apps are far less expensive. Less than the price of a single astronomy book, even.

SolidWorks is THOUSANDS...

 

OnShape is free

[Fiske]

I'm using SkySafari Pro on an iPhone 13 now.  Looks like if I'm going to start getting more serious about double stars, I'll have to get a device with a larger screen.  These skylists with several hundreds - even a 1000 or more objects - are seriously cluttered on the small screen of an iPhone.  Time to shop for a 12" tablet. 

 

Mike

  

 

My Tab A8 was $199 at Costco. 

[jrazz]

Haven't quite been able to split these yesterday (the clouds rolled in) but this is high on my list of things I want to observe in my binoculars:

 

STF 1964 AC m 8.1, 8.1, sep 14.5" at PA 90 degrees.

 

STF 1964 CD m 8.1, 9.0, sep 1.5" at PA 20 degrees.

 

HU 1167 AB m 8.1, 9.9, sep 1.2" at PA 80 degrees.

 

 

I do think this will be limited to the BT though. I doubt the 34x80 can do it.

[Sarkikos]

  

 

My Tab A8 was $199 at Costco. 

Ideally, I'd like to find a 12" tablet that does not bleed white light between the pixels.   I'd like to use SSP on the tablet for deep sky objects as well as double stars.  Flooding the eyes with white light from a tablet that you think has a dim red display is not ideal.  

 

Mike

[Fiske]

Cover whatever tablet with red acetate. 

[Sarkikos]

Cover whatever tablet with red acetate. 

I've used the old Rubylinth filter in the past, but it makes the screen image a bit fuzzy and it also lets through non-red light.  Yes, it does.  So, not ideal. 

 

There was a much better filter available until a few years ago.  It was dark red and did not transmit any light except red.  Unfortunately, I only have a couple pieces left of this filter.  I'm not sure if they would fit over a new tablet.

 

It's better to have a screen that works well out-of-the-box for amateur astronomy without having to attach a filter.  We shouldn't have to attach a filter.

 

Mike

Edited by Sarkikos, 22 July 2023 - 11:45 AM.

[jrazz]

OK, managed to observe STF 1964CD and HU 1167AB

 

STF1964CD

15h 38m 14.14s +36° 14' 49.7" P.A. 19.90 sep 1.5 mag 8.06,9.02 Sp F5 dist. 27.59 pc (90 l.y.)

 

HU 1167AB

15h 38m 12.91s +36° 14' 48.6" P.A. 80.50 sep 1.2 mag 8.07,9.87 Sp F5 dist. 110.25 pc (359.64 l.y.)

 

Honestly, all I can say is "meh". It's nowhere near as spectacular as the double double. They're fairly tight but the BT-100/TOE4mm is just an unbeatable star splitting combo. Still, dim and uninteresting very much unlike Zeta2 Coronae Borealis!

 

STF1965 (Zet2 CrB)

15h 39m 22.68s +36° 38' 09.0" P.A. 306.00 sep 6.3 mag 4.96,5.91 Sp B7V+B9V dist. 145.14 pc (473.45 l.y.)

 

Vivid Aqua blue double very very engaging and pretty! totally recommend!