Wednesday 26 October 2022

Wide and far apart

 

 
No challenge to split this pair, yet they look very nice with their attendant stars.

Two Blues

 

With a spectrum of A7 this is a very blue pair, a sparse area with few field stars

Draco Double

 

One magnitude and 3.5 Arc seconds separate this pleasing pair of G type stars in Draco

A warm pair in Hercules

 

 
A fairly close 3.5 Arc Seconds separates this nicely balanced pair, the F0 
class giving the A star a faint hint of orange.

Friday 29 March 2019

Two doubles and a cluster with a double too!

NGC2169 is a small, but bright and compact open cluster in Orion, about 7 degrees north of Betelgeuse. Mainly blueish stars, it is an attractive object in the eyepiece and has the added bonus of a nice double star, Struve 848, with a separation of just 2,4 arc seconds, this double requires a fairly steady sky to split the pair. They both looked white, but fainter stars tend no to show much in the way of colour anyway.

Images are drawn at the eyepiece then photographed and edited in photoshop to tidy up the stars, the positions are left as seen, the text is also tidied up.








Struve (STF) 738 is a neat double star very easy to find as it is part of the loose cluster of stars that form the "head" of Orion, to the naked eye this is the faint triangle of stars that lie between Betelgeuse and Bellatrix which form the shoulders, this group then is the head.

The double itself is an uneven pair, the primary being magnitude 3.5 the secondary is 5.45 and visually the difference is very noticeable. Both stars are white in colour.



Struve 742.  An evenly matched pair of stars that lie quite close to M1, the crab nebula in Taurus, with a 4" separation, this pair are not too tricky to split, and show a pale yellow and blue colour.


Monday 30 October 2017

Gamma Delphini



Finally, a night just about suitable for some observing!  In preparation for the November main item, I wanted to sketch this double, a nice easy to find pair, the primary star was a cream yellow, about right for a K type star. The Secondary was white to blue white, which matches the newer spectral class of A2Ia+ found in stellarium, The WDC has it as an F7V as found in the Skymap info (I used that for the notes on the image, too late to correct it now!)  This is an actual binary pair.

 In a previous observation on 18 Jun 2000 I recorded the secondary as slightly greenish.

 "Primary yellowish, secondary greenish but this is very subtle and not easy to pick up, seeing was poor with increasing cirrus but at 200x the colours were there."

This time there was a first quarter moon not far away, but in 2000 there was a full moon, but very low down in Sagittarius, so it would have been less of an influence.

Thursday 6 October 2016

2016 Double Stars

Finally, a decent night with goodish seeing, not perfect, but acceptable anyway. 

First off, a famous double, the so called double double in Lyra, also known as Epsilon 1 and 2 Lyra.







Next up is STF (Struve) 2104, an uneven pair separated by 5.6 seconds of arc, the primary is an F type star and looked white, the secondary's class is not listed but it looked somewhat orange.