Beautiful Yellow/Blue double in Canis Major

[Rodstar (Rod)]

Even if you are not into double star observing, you should have a look at the following double, while Canis Major is still in a good position:

HJ3945 (SAO 173353), RA 07:16.6 Dec -23:18

The magnitudes are 5.0 and 7.0 respectively, with a separation of 26 arcseconds, which makes it an easy object in any telescope, or even binoculars.

I used this object last night to show children aged 4, 5, 7 and 10 that stars come in lots of different colours. Everyone who looked said "Wow!". Some of the same children were unimpressed with Omega Centauri ( a difficult audience indeed). It is definitely worth a look.

I would liken this double to the much better known Beta Cygni (Albireo).

I have some other fantastic colour doubles to hunt down on Saturday night, so I will post some more in due course!

[RB (Andrew)]

Fantastic Rod,

Thank's for the report. I'm gonna check 'em out too.

[vespine]

Yeah sounds good!

Could someone be a champion and post a screen shot from their PC, like a sky map finder chart for this double? Like I've seen in some other posts here from a star map application?

I have a dob scope and am still way too newb to find objects by co-ordinates...

[ving (David)]

you got any star charts vesp? if not download cartes du ciel for free

[vespine]

Yeah I bought Astronomy 2006 and downloaded and printed the awesome free charts linked in the beginners forum! But unless someone actually pointed to it on the chart I'm not sure I'd be confident pin pointing it, stars are not named on the charts...

I did download an open source program (name escapes me just right now) but I've not tried to locate stars with it yet! Didn't even think of it.. I'll try it when I get home

[Rodstar (Rod)]

Vespine, if you get a copy of the Jan/Feb edition of Australian Sky & Space there is an article on doubles in Canis Major by Richard Jaworski which includes this double. The article has a photo of the double, as well as a map of Canis Major which indicates its location.

[Miaplacidus (Brian)]

Yeah, I checked out this double for the first time about a month ago (before the clouds came down). Beautiful, and very like Albireo. Interestingly, I have the SAO as 173349; must be one of the stars. Anyway, this is a gem in little scopes. Has anyone determined yet if these stars are related?

[mickoking]

G,day Rod,

h3945 is one af my favorite wide double stars in the sky and for us southeners hell of a lot more convenient than Alberio. Speccy open cluster NGC 2362 is in the same finder field.

[ving (David)]

g'day doug!
welcome aboard fellow rosemeadowian!

[CosMos (Rich)]

Originally Posted by vespine

Yeah sounds good!

Could someone be a champion and post a screen shot from their PC, like a sky map finder chart for this double? Like I've seen in some other posts here from a star map application?

I have a dob scope and am still way too newb to find objects by co-ordinates...

This adapted map is from Uranometria showing the star in question.

[vespine]

hey thanks! From my charts I should be able to work that one out now. I was going to look for it last night but got caught up looking for stargate and sombrero amongst other things

[OneOfOne (Trevor)]

Originally Posted by vespine

...but got caught up looking for stargate and sombrero amongst other things

Actually, I was out on Wednesday and Thursday nights and found the Stargate on the list so I swung over to it. I must admit, it may be small, but for something with just 6 stars in it, I reckon it is one of the most impressive asterisms I have found. It took a while before my wife was able to pick out the third star in the central triangle. For those who haven't heard of it, it is a triangle of stars within a triangle of stars in Corvus. Also looked at the sombrero too, but until the neighbours put curtains up on their new extension I get cop an eyeful....of light that is!

[ving (David)]

the stargate is pretty interestinghey
theres some hockeystick shaped cluster right near it and m104
interesting arrangement too