[Aavso-photometry] VarVul05 last night

[Justin Pryzby]

Following the IRC recommendation of Wolfgang Renz, I engaged last
night (2005-09-09,10) in unfiltered CCD photometry of the M27 field
where a new variable was discovered some 3 weeks ago.

A calibrated image resulting from a single 20 minute exposure may be found at:

  http://justinpryzby.com/m27.00000001.Dumbbell_Nebula.FIT

The nova is easily visible on last nights image; compared to Michael
Richmond's image visible from several nights ago (2005-09-05,06), when
it was barely visible:

  http://spiff.rit.edu/richmond/ritobs/sep05_2005/sep05_2005.html

Michael apparently used the same telescope, but with a different
camera, giving 1.9 arcsec/pixel, rather than our 1.1 arcsec/pixel on
our setup (TEL 0.30-m f/10 Schmidt-Cassegrain + 765x510 CCD + f/6.3
focal reducer), and he also used combined exposures of shorter
duration.

Michael was unable to get a quantitative photometric measurement, due
to the dimness of the object, but indicated that it (unresolved from
object "R") was of comparable brightness to object "O":

  B=20.074, V=18.745, Rc=18.389, Ic=17.610

On my image, on which I have yet to perform any quantitave analysis,
the nova is resolved from neither of the nearby comp stars "O" nor
"R", but is of comparable brightness to object "H":

  B=18.998, V=17.656, Rc=16.812, Ic=16.013

and noticably brighter than object "L" (with which there is are
interfering objects):

  B=19.573, V=18.207, Rc=17.858, Ic=17.202

It appears that the object has increased in brightness in the last few
days, and Wolfgang would like to encourage continued observation to
help confirm the star's type.

Justin