Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_celestial_motion.thumb.jpg.a9e9349c45f96ed7928eb32f1baf76ed.jpg

Recommended Posts

Hi. Was up at dawn observing Mercury rising in the southeast and slowly swept my binoculars left. I was able to vaguely see a small triangle formed by Upsilon Ophiuchi, HR  6128 and HR 6137. That was the limit of view as sunlight was washing out anything else to the left of that. But I clicked on the adjacent HR6144 star in my Sky Guide app and it lists as being 6,900 light years away. When I checked the Ski Safari app, the same star is listed as 1,900 light years. I went online and found little info but, “In the Sky” web page it’s HR 6144 at 9 kilo years / 9,000 light years. Does anyone have any info as to why the huge discrepancies?

https://in-the-sky.org/data/object.php?id=TYC5627-1490-1

Thanks in advance for your help. 

Share this post


Link to post
Share on other sites

Stellarium has it at about 4500 ly.

Apparently, its  spectral type is A9 II/III, somewhere in the giant to bright giant range. It may be difficult to pin down its precise absolute brightness, which of course has a bearing on its distance.

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HR++6144 call it a post asymptotic giant branch star and a proto planetary nebula.

 

  • Thanks 1

Share this post


Link to post
Share on other sites

Ruud, thanks very much for the concise explanation. All those numbers at Simbad make my head orbit. 

Share this post


Link to post
Share on other sites

From Gaia the parallax is 0.3612 mas

To find the distance in parsecs divide 1 by the parallax in arcsecs.

For this star it will be 1/.0003612 = 2768 parsecs
A parsec is 3.26 light years so this star is about 9000light years distant.

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, wxsatuser said:

From Gaia the parallax is 0.3612 mas

To find the distance in parsecs divide 1 by the parallax in arcsecs.

For this star it will be 1/.0003612 = 2768 parsecs
A parsec is 3.26 light years so this star is about 9000light years distant.

The parallax error in DR2 is +/- 0.0557, so the star's distance is between about 7,800 and 10,700 light-years. I believe these small parallaxes (large distances) are not so reliable in this data release.

Edited by Waddensky
  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, Waddensky said:

The parallax error in DR2 is +/- 0.0557, so it's distance is between about 7,800 and 10,700 light-years. I believe these small parallaxes (large distances) are not so reliable in this data release.

Yes, just showing an example so the op can see if the quoted distances are close or not.

 

  • Like 2

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By BinocularSky
      The August edition of the Binocular Sky Newsletter is ready. As well as the usual overview of DSOs, variable and double stars, this month we have:
      * A grazing occultation of a bright star
      * Moon occulting stars in the Hyades
      * See both ice giants as well as Vesta
      * Review of the Celestron EclipSmart 10x25 solar binocular
      I hope it helps you to get the best out of these late summer nights with your binoculars or small telescopes.
      To pick up your free copy, just head over to http://binocularsky.com and click on the Newsletter tab. You can also subscribe (also free) and have it emailed each month.
      Warning: Do not attempt to observe the Sun with any optical system that is not specifically designed for the purpose.
    • By MaHa
      Hi all, 
      I've decided to stay in the house tonight with the anticipation of some clear skies later on, and to hopefully get the chance of splitting a few double stars - something that I've never done before. After a while looking through some charts at my desk with a rather nice glass of red, I've come to the conclusion that Cygnus and the Northern Cross seem like a pretty good place to start. 
      My first port of call will definitely be Albireo at the foot of the Cross.. I'm excited about this one as it sounds like a beautiful view through a pair of binoculars, not to mention the easiest to find! I'll then move over to the Cygnus triple all being well and then the three doubles (Mu Cygni, 79 Cygni and 61 Cygni). 
      Now all that's left to do is await the darkness, and hope the clouds disappear! 
      Hope you're all having a great weekend.
      Cheers, Mark 😁
       
       

    • By Kcks Regulus Star
      On the 2nd of July I closed my curtains one night before I went to bed but, before they were shut I noticed a strange multicoloured light flickering low in the sky in the northern celestial hemisphere. I Thought to myself if that is a star it looks amazing. The next night (3rd of July) I decided to take another look at this multicoloured light which was still there, Only this time I used my binoculars, I was seeing blues, greens & reds. We have all seen stars by looking up into the sky but, I have never seen a star create multi colours before. It makes you feel excited inside and you think that no one else can see this until you tell them and share the same experience together. I believe I was looking at the Capella Star which is the brightest star in the constellation Auriga and your not kidding it is bright. I cant wait to have another look tonight to see if the multi colours are still there. I would like to have taken at picture of it but I am not setup to do that just yet as I am very new to star gazing. I wish someone here can confirm what I saw and to post a picture of it would be awesome. 
      Nikon Prostaff 3s 8 x 42
    • By Mark Daniels
      Thought this might be of interest
      made binocular tripod modification to use my25x100 celestrons. The original tripod was redundent so added £30 of steel and bits and it works well. Bit of refining but may be later!






×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.