h3945 double star

[cookie1]

Hi,

I was looking at the "Astronomy 2014 Australia" book in the Feb chapter and they feature h3945 as something to look at this month. So I look at the charts and looks pretty straight forward. So I fire up Skysafari Pro.. cant find it, not in the database. Fire up Starry night Pro, cant find it either. So now I'm a big confused why these major astro apps dont have this and other things featured in the Astro 2014 book?

I found this post (http://astrobob.areavoices.com/tag/h3945/), but it didnt really help my issue. Any thoughts?

cheers

[noeyedeer]

hi cookie,
it's not HD 3945? which constellation is it in?
is it in this list? users.compaqnet.be/doublestars/

matt

[mithrandir]

Paul, h3945 is in SSPro 3 and SSPro 4 by one of its other names. Details as shown in CdC:

WDS HJ 3945
Information from catalog: WDS
Washington Double Star catalog
Component 1 magnitude: 5.00
Component 2 magnitude: 5.84
AB
Separation: 26.4
Position angle: 52
Date: 2008.00
Spectral class: 1 K3Ib dF0
Description: LD BD-23.05189
Coordinates: Apparent
Apparent RA: 07h17m14.4s DE:-23d20'47"
Mean of the date RA: 07h17m12.5s DE:-23d20'29"
Mean J2000 RA: 07h16m36.8s DE:-23d18'56"

[mithrandir]

Matt, h3945 is also known as 145 Canis Majoris, HR 2764, HD 56577, SAO 173349, BD -23 117, CoD -23 5189, HIP 35210, HJ 3945, ADS 5951, WDS 07166-2319, and TYC 6537-3290-1

[Tony_]

Starry night lists it as HIP35210

[noeyedeer]

here's a bit of a write up about it www.theskyscrapers.org/h-3945-canis-majoris

[Astro_Bot]

And that's the second biggest problem in Astronomy, IMHO, the biggest being light pollution.

Isn't it about time there was a universal catalogue?

[noeyedeer]

thanks thought it maybe been a typo, obviously it's not :) can confirm it's in my version of SS too using the HR designation

matt

[pfitzgerald]

Here you go - and thanks for posting about it as I intend to have a squiz at it myself :-)

After a bit of a Google I found this:

https://groups.google.com/forum/#!topic/alt.astronomy/5T6Ru-K2RZk

Scroll down and you'll find this reply posted for the original poster of the thread.

"... the double which is 'called' 145 Canis Majoris is indeed h3945 (ADS 5951 for those of you using that catalog)."

The primary is SAO 173349, a yellowish-orange magnitude 4.8 star of spectral class K3, and the companion is SAO 173353, a magnitude 6.8 bluish-white star (spectral class F0). The separation is 26.8 arc seconds at a position angle of about 53 degrees (l985).

They may not be an actual physical binary, as their parallaxes are not the same. Still, they are a stunning pair, truly deserving their "Winter Alberio" name given to them by some amateur observers. Clear skies to you".
David Knisely

Hope that this helps you to find it. I've tried the SAO numbers in Voyager 4.5, and both stars are there.

Kind regards.

Paul

PS: SAO 173349 also has the designation HR 2764 and its coordinates are:

RA 07h 17m 13.14s
Dec -23o 20' 38.0"

PPS: In the time it took me to read your post, Google it etc six other posts went up! Wow! How's that for help and service? Gotta love the ICE Forumites!

[mithrandir]

That list isn't complete either. It is just the names that are listed by SSPro3/4. Search Vizier for stars within 1 arcmin of 145 Canis Majoris and you get more catalogs than you could poke a stick at.

[noeyedeer]

looking in the double star atlas there's quite a few double stars in the area around h3945. it even lists this combo as a pity that it's not mentioned more often. thanks Paul for bringing light to this little baby. if only the cloud stays away!

[cookie1]

Thanks for the swift and detailed replies. A trap for new players no doubt :)

Is there an online catalog I can search in future if I come across name issues like this? Does the Astronomy 2014 use a specific naming convention or catalog ?

cheers

[mithrandir]

Paul, you can try the name in Vizier http://vizier.u-strasbg.fr/viz-bin/VizieR or Simbad (query by id) http://simbad.u-strasbg.fr/simbad/

If those can't find it then try Google for either an alternate name or an entry with the co-ordinates. You can then put an alternate name or the co-ordinates into Vizier or Simbad (query by id or co-ord as appropriate).

[Steffen]

Paul, if your SkyWatcher Dob is a goto or push-to, the SynScan hand controller has the star in its doubles list as 145 CMa. It is one of my favourites in fact, a wide double but very pretty, similar to Albireo.

Cheers
Steffen.

[cookie1]

Steffen, Unfortunately no guiding aids on this scope.

Andrew, thanks for the links, I will check them out.

cheers

[Robh]

Hi Paul,

You might find this useful. Double Stars by constellation at the Eagle Creek Observatory website.
http://www.eaglecreekobservatory.org/eco/doubles/

If you are having trouble with the name of the double, you might be able to pin it down by coordinates or the magnitudes and separations of the components. If you click on the name (left column), it will give you a direct link to SIMBAD which lists all its identifiers.

Regards, Rob

[ausastronomer]

Hi Rob,

That Eagle Creek website is an excellent resource, which I have referred to on and off over many years. Like most websites put together as a labour of love, it contains a couple of minor errors. One in fact is the SIMBAD link to HJ 3945. I haven't checked but I think they may have given a link to the secondary component, not the primary.

Here is the correct SIMBAD link

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=SAO%20173349

Cheers,
John B