ASAS1749-13 = NSer2005 = V378 Ser
Observations: 5 Apr 2005
6 Apr 2005
Updated: 7 Apr 2005, 13 Apr 2005
V and B photometry measurements are reported for this nova.
This object was discovered by G. Pojmanski with the ASAS (CVNET-discussion 3 Apr 2005)
on 18 Mar 2005 and first reported as a dwarf nova. Further observations
reported on CVNET-discussion give variations of amplitude < 0.1mag and B-V=0.7.
It is a nova (NSer2005 = V378 Ser).
The observations were carried out with a 203mm SC telescope, Johnson B and V filters
used alternatively and a SBIG ST7E camera (KAF401E CCD). Each exposure is 1 minute long.
36 images were obtained with the V filter and 32 with the B filter.
A sample image is here.
The comparison star is Tycho 2 5669-00822 with Johnson magnitudes
(computed from the Tycho magnitudes) B=11.191 V=9.731. There are 2 check stars K and K1:
K star is Tycho 2 5669-00675 with Johnson magnitudes B=12.443 V=11.257. It is observed
with b=12.600 (standard deviation 0.056) v=11.534 (0.023);
K1 star is Tycho 2 5669-00677 with Johnson magnitudes B=11.952 V=10.972.
It is observed with b=12.166 (0.030) and v=10.927 (0.010).
The discrepancies in the check stars between Tycho magnitudes and
my measurements may come from:
the guiding is not very good and I did not use the photometry apertures
that large because the field is crowded;
the sky was hazy;
I was not able to make flats so I use old twilight flats;
the photometry was not transformed.
The light curves:
Blue: the B magnitudes, Green: the V magnitudes. The error bars
are +/- the 1-sigma statistical uncertainties. They are large at the end
of the session because of the twilight.
From UCAC2, the 2000.0 coordinates are:
with an uncertainty of +/-0.5".
I searched for a counterpart in the USNO-B1.0 catalog, taking into account the
proper motions. I found none. Either the precursor was too faint for
USNO-B1.0 or the proper motion is not known.
Telescope and camera configuration.
Computer and software configuration.