[vsnet-alert 10768] re Nova Car 2008: astrometry

[bydra at Safe-mail.net]

Greg Bolt reported :-

"I imaged Nova Car 2008 on 28.8 Nov 2008 UT.

Average astrometry for several images is:

11 13 53.78 -61 13 48.2 ... All residuals were < 0.4"

cheers,
Greg"

Lovely stuff!!

Using CDS Aladin there's these field images from SERC and HST :-

http://i33.tinypic.com/nf2rmx.jpg

top left is SERC I, as noted by Brian S., bottom left is HST STIS MIRVIS, essentially unfiltered CCD.  Greg Bolt's position is pointed to via the red arrow, and a black bar is also marked next to an adjacent field star for pattern recognition, as the object is at the edge of the HST images.

Top right is AAO R, with another HST exposure at bottom right.  Notice the background for the R plate.  It's "foggy" with Halpha here, in fact the SuperCosmos Halpha images here show few stars because of this "fog".

All images same scale (scale bars bottom left of images) and orientation, via Aladin.

Zooming in on the HST images

http://s4.tinypic.com/16kul4g.jpg

there's another star about 1 arcsecs East of Greg Bolt's position which is just about plate limit visible on the AAO R plate once you're aware of it.

But not much else, and as can be seen the field goes a fair bit fainter.

There is of course immense visual extinction in this field, but I suppose the nova must be somewhat foreground of most of that to be visible at all, even at maximum, given the visual extinction seems to be over twenty magnitudes or more.  Dunno.

Brian Skiff's xray source point just due South is well noted.

It seems that these two stars are too faint for the spectra image and possibly even only just off the edge of field.  Not sure, I could be wrong.

Cheers

John