Jump to content


- - - - -

12 Del, STF 2727

art double star observing report Orion refractor sketching

12 Del, STF 2727

This is the third of three sketches rendered over the evening of August 25-26, 2017 at HAA. The pair is also known as Gamma2 Del. The sketch may seem a little cluttered with all the field stars labeled, but if you have it for a reference when you're observing, it may help. The exercise of identifying them with my SkySafari is a challenge.
I picked out this double from the Sky and Telescope List of Colorful Doubles Rob Ratkowski forward to me found here. Stelle Doppie lists it as a triple, with the C companion at Mag. 16! (Not going to get that!) You can find it here..
This pair is a sort-of Albireo color contrast. I saw the primary as golden yellow and the companion as a silver blue. Haas has Smyth attribute the colors to "Yellow; light emerald," and says Gore stating the colors as "reddish yellow; grayish lilac." SkySafari attributes the Spectrum of the primary as K1IV, subgiant and the B companion as F7V, main sequence. What colors do YOU see?
There is one star that proved difficult. That is TYC 1634-2579 listed at Mag. 10.07 just to the SE of the pair. I have it in the Low Power Ocular and the Medium Power views. I think that it's a bit dimmer that that, maybe 11.5 or dimmer. I had a heck of a time nailing it. John Nanson did and confirms the Mag. 10.07 from UCAC5 and URAT1. So I don't know why I had a hard time getting it.
I've added the Julian Date and since Rob Ratkowski turned me on to the "Telescope Calc" app I've got the FOV labeled as well.
This has been a great leap in the development of my sketches.
I'm about to purchase a TeleVue Delos 6mm EP. I can't wait to try it out with my Vixen to see if I can get some 11th and 12th mag. stars. That will open up a whole spectrum of double stars that I can sketch!!!!
So, there you have it. Another beautiful colorful pair observed at the summit at the GREAT HAA location. Thank you IfA and Rob Ratkowski and everyone who has contributed to making this observation location as fantastic that it is!
Looking UP,
Steve McG. MauiGazer

    Cloudy Nights LLC
    Cloudy Nights Sponsor: Astronomics