[vsnet-chat 3575] re NSV 12041

["." <crawl@zoom.co.uk>]

Hitoshi Yamaoka wrote:
 
>   On the other hand, NSV 12041 (ME) exists in the neighbour, but at
> this position (1950.0) there is no counterpart on DSS images.
> 
> >12041   192459. -214200:M                         731059  1922.0-21 ME
> 
> I cannot seek this reference "731059", so the identification is not
> firm.  Could someone kindly refer it?

Unfortunately there is no electronic edition of the references to the
NSV, and you have to have the printed copy to get at them.

So it may be just as easy to email the Sternberg Astronomical
Institute's GCVS research group direct [sorry, I have no contact email
for you].

I can tell you that the first two digits are a year date, and as the
lack of magnitudes, in tandem with the broad spectral type, suggested an
objective prism survey I tried a search of said for 1973 using the NASA
ADS server, but with no success.  Anyway, objective prism derived
positions are often a bit iffy.


Meanwhile, Brian Skiff Wrote:

>      I note that the 2MASS position is more than 1" from the USNO-A2.0
position
> for the faint red star.  Given that they are both ICRS-based catalogues,
> either the 2MASS position errors are overstated or there is perhaps some
> proper motion of the star.  Given that the star is probably saturated in the
> 2MASS data, another possibility is that the 2MASS position is poor due to
the
> software being unable to provide a good centroid.

The 2MASS catalogue data itself contains the information that this 2MASS
object is 1.2 arcsecs distant from the suggested optical identification
with the USNO A2.0 star. A position angle of 216 degrees is given for
this separation and it is noted as the only nearby optical candidate
[within a 2' radius, I think].

The J, H and Ks magnitudes are fairly near the upper limit of the
survey, it being rare to see any listed as brighter than 5. The
magnitudes are flagged as being affected by a diffraction spike from the
nearby "brighter" star. The image is a bit warped when you look at it
with the 2MASS image viewer.

[As with the Tycho catalogues and other modern catalogues, the 2MASS
data has many quality flags and info associated with its data that is
often ignored].


As for the IRAS PSC and FSC positions discussed by both Taicho Kato and
Brian Skiff, I note that the brighter star that is possibly associated
with the FSC position has a Tycho1 BT-VT colour index of around +1.9,
which seems reasonably red for an FSC object.

So, the PSC source could well be for the faint star (especially given
the proximity to the 2MASS position), and the FSC one for the bright
star.

John

JG, UK

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp