Where is the Mistake?

[theodog (Jeff)]

Hi All,
While checking a deep field I took last night, I compared it to my copy of Guide 8.
I found a mapped star that clearly is not there.

Could you check your starmaps to see if it is also there?

I am wondering if the mistake is in this software or in the catalogue it draws from, ie GSC.

[Karls48 (Karl)]

That missing star does not show on SkyMap 11

[Merlin66 (Ken)]

Jeff,
Obviously an error in the database; doesn't show in CdC V3 CSG either....
I have the USNO catalog installed ( goes down to >18mag) and was impressed with the limiting magnitude of the image!!!
What equipment and exposure???

[Ian Robinson]

There is actually a faint star near the right position , it may actually be WR star or recurrent nova or a flare star , you should report your finding / discovery.

OR


There is an error in the catalogue entry (which means it will be in all commercial charting packages since they all use the same data sets).

[Merlin66 (Ken)]

Jeff,
Ian raises a good point! have you clicked on the rogue star to see if it gives any data???
I don't have ALL the available Variable star catalogues installed, but I do know that not all the mapping software programs use the same versions of CSG ( there are about three versions.....) and even then some are complied in a modified format to suit their search and display algorithms. TheSky GSC database can't be read by CdC etc.
For stellar images fainter than 12 or 13 mag the Tycho or USNO ( or latest versions) are better.

[theodog (Jeff)]

It seems the star only appears when I import B1.0 data from the internet.
Here is the information window on the star.
It states that this data can accumulate, so I clicked to delete the accumulated data and reloaded it. The star re-appeared.

The image is a sum of 2x 3600sec subs -dark fields, through a 12" f5 using a ST-7e and AO7. See FITS header

[Merlin66 (Ken)]

Interesting... This "rogue" star doesn't show in the USNO A2 series??
BTW did you notice, what apperas to be an asteroid track at the top LHS, just to the side of GSC 5799-79???
Using your time stamp I ran my asteroid paths but nothing showed up???

[theodog (Jeff)]

Originally Posted by Merlin66

Interesting... This "rogue" star doesn't show in the USNO A2 series??
BTW did you notice, what apperas to be an asteroid track at the top LHS, just to the side of GSC 5799-79???
Using your time stamp I ran my asteroid paths but nothing showed up???

Well spotted.
Yes, there are two asteroid tracks.
I've identified them from the MPC site. It was while doing this that I found the "strange" star on my star map.