Making the most of nautical dark w/ a few double stars - 08/09.06.24

[josefk]

I am steadily working way my way through the Astro League double star observing programme, by no means in a hurry or with any kind of diligence but, bit by bit when the mood takes me and typically with a GnG small scope for the enjoyment of the find as much as anything. Nautical dark last weekend seamed like as good an opportunity as any to make some progress and i set the TOA up on push to so i could "crack on" as it were. One of the requirements of the AL programme is that the double stars are sketched (or at least plotted) so here are a few:

Struve 2010, Kappa Herculis, 'Marsic': a lovely pair of very yellow (even orange) suns. 

 

Struve 3127, Delta Herculis, 'Sarin': The primary here was also a lovely golden hue. In the AL programme this is "just" a double but sketching is brilliant for the extra data capture. My field sketch picked up "bonus" C and D components too to grant an observation of the full system.

 

Struve 2264, 95 Herculis: I sketched this at the bottom of the EP FOV deliberately because the cascade of stars falling north to south was so aesthetic. Recommended.

 

Struve 2417, Theta Sepentis, 'Alya': Seeing was mediocre last weekend so i saw very few diffraction artefacts, I think this pair cam closest to that nice bullseye view. Again my sketch enabled me to pick up the C component as a bonus.

 

This was a nice "double double" - Struve 1998 (Xi Scorpii), and  Struve 1999 together. The AL league doesn't require a split of Xi Scorpii AB (@ 1.1") and that's a good job (on this evening) because it was only just detectable as a binary star itself (even with the mighty TOA), it was never close to being resolved (peanut) nevermind split. Xi Scorpii AB C was a nice split though with a yellow AB. Struve 1999 (which is possible in the same FOV at this magnification) made a lovely contrasting blue A B pair and again i could collect a full set with the fainter more seperated C component because i'd picked it up in my field sketch 🙂 

 

Struve 2816 and Struve 2819 are again a nice 'double double" possible in the same FOV. The AL programme doesn't require the 1.8" AB of STF 2816 to be split and again it was a good job (on this evening) becuase it wasn't going to split. This pair did resolve into a peanut shape though with narrow (ish) waist. STF 2819 isn't on the AL programme but is a visually obvious pair to the east of  2819. This whole FOV is a very sparkly enjoyable star field. I didn't try to capture any of the rest of the FOV on paper at all.

 

As in indicator of the night being less than ideal for tighter pairs, here's Struve 1864 (Pi1 Bootis) at high magnification (relative to rest of the obs here). A B here are at 5.4" separation. There was clear black space but not so much as you would expect. Again the more distant lower magnitude C was a bonus "collected after the fact" becuase it was captured in my field sketch.

 

I may or may not ever get round to submitting my AL double star sketches and logs to the AL for "validation" and nifty pin badge (though i do fancy the pin badge) but nevertheless just working through this programme has been a great tutorial and skill builder in this aspect of the hobby. I recommend it.

 

Cheers

Joe

[SwiMatt]

Nice sketches @josefk! Are you also estimating the position angle yourself, or do you just report it on your sketch from StelleDoppie?

[Ed astro]

Great sketches! I really like the colors on  these. 
if the sky unexpectedly clears up this weekend I will have a look at some of these doubles. Seems like a great way to keep yourself busy during this time of the year.

[Alan White]

I am following your journey with interest Joe,
you are managing a decent amount of sessions, or perhaps it just feels like it.
Love the sketches.

 

[Emperor!Takahashi!]

These are great!

Can I ask how you go about adding color to your sketches? This has always baffled me with double stars. I can see the color at the eyepiece. But how to add it to the sketch, especially when using a dim, red light? Or when sketching on white paper that I later invert? The best solution I've thought of is to note the color and then add it later using some software. But I've never done that because I'm lazy.

Anyhow, I really like these sketches.

[josefk]

6 hours ago, SwiMatt said:

Nice sketches @josefk! Are you also estimating the position angle yourself, or do you just report it on your sketch from StelleDoppie?

Thanks @SwiMatt

On the cards are the official numbers from StelleDoppie but my field sketch always includes notes for:

1. separation estimate (I’m not too bad with some EPs when I get my eye in but can be bad with wide angle EPs early in the night),
2. position angle (I’m normally +/- <10-degrees or +/- 10-degrees plus 180-degrees if I mix up which star is the primary). Sometimes I’m bang on. It’s pretty fool proof to centre the star then watch it cross the field stop and work it out),
3. relative magnitude (obviously brighter, about the same, obviously dimmer is about as sophisticated as it gets - I can’t estimate magnitude),
4. colour,
5. nearby asterisms or other points of interest.

I’ll put up a couple of examples. The separation and PA estimating have been skill building for sure 👍🏻

 

[josefk]

Thanks @Ed astro - I recommend it. Last Saturday/Sunday I couldn’t even see some showcase DSO it was so light, doubles made for a great diversion. 

[josefk]

3 hours ago, Alan White said:

I am following your journey with interest Joe,
you are managing a decent amount of sessions, or perhaps it just feels like it.
Love the sketches.

 

Thanks @Alan White  TBH and rather perversely the absolutely rubbish and unreliable weather has made me even more focussed on getting out at any opportunity and for as long as possible at each time. In previous years I would never stop out late on a night before work for example but this year I’ve done it a few times and seem to manage the sleep debt ok. Needs must 😂

[josefk]

58 minutes ago, Emperor!Takahashi! said:

These are great!

Can I ask how you go about adding color to your sketches? This has always baffled me with double stars. I can see the color at the eyepiece. But how to add it to the sketch, especially when using a dim, red light? Or when sketching on white paper that I later invert? The best solution I've thought of is to note the color and then add it later using some software. But I've never done that because I'm lazy.

Anyhow, I really like these sketches.

These are “tidy” next day (or in this case a few days later)  versions of monochrome field sketches which I do black on white. My field notes include descriptions; yellow, yellow towards orange, silver blue, striking blue, blue grey, dim grey etc. I know what I meant later while ever I retain the memory of the observation. It wouldn’t work if I left it too long or created a big queue of sketches to tidy up. I also tend to systemise my descriptive language as it were so the prompt is simple and repeatable. 

Similarly if I overdo the star magnitudes with “blobby stars” that grow too big under red light conditions (I make this mistake a lot)  - I simply make extra thumbnails and notes till I’m happy I’ve got a good base to tidy up later. 

[AlcorAlly]

Very inspiring @josefk, thank you for sharing