A Search for Novae in the Andromeda Galaxy
Paul B. (P.I.) and the Astronomy Classes of Grosse
Pointe North and South.
Purpose
The purpose of this year's NovaSearch project was to analyze
new and existing observational data for new novae, continue observations
of any new novae that may have continued into the latest set of observational
data, and to organize and verify the novae found in the past two years.
Procedures
This year, we were provided with two new epochs of data,
and improved macros for novae analysis. All the old novae data were redone,
and higher standards for results were set than in past years. Many new
novae were discovered, and all the information was compiled into a single
database. A new numbering system was given to identify when the nova was
discovered.
Data Tables
The new data table contains more information than past years,
and all old novae were reanalyzed to meet these standards. The table consists
of 13 columns, detailed below.
Nova - Number to identify individual novae. Format
is YY-###.
SR - Subraster.
Epoch - Epoch.
X & Y - X/Y Position in image.
Scale - Scale used.
RA - Right Ascension. Format is 00h:m:s.
Dec - Declination. Format is d:m:s.
SS Used - Standard stars used.
SS Err - Standard star error.
Im Err - Image error.
Comb Err - Combined image/standard star error.
Mag - Magnitude.
The new numbering system was implemented primarily to distinguish
novae discovered in past years from novae discovered this year. The X/Y
and scale were used only to locate the nova in the image. The image error
was found by calculating all the magnitudes for the standard stars used,
and recording the variance.
Data
All data from past years were reanalyzed and recalculated
using the latest set of macros and observational data. This year, we discovered
a total of 25+ (21 fully analyzed and included in data table) new novae,
5 of which had a duration of 2 or more epochs. Of those 5, we identified
4 to be Type NB and 1 to be Type NA.
Data Revisions
While verifying our data from past years before adding it
into the new database, we discovered that several novae continued into
the new epochs we were given. We also were able to find several novae which
continued beyond what was previously thought. Light
curves have been recalculated and included for these.
Analysis
The observational data were analyzed using NIH Image and
the NovaSearch macros provided on the RBSE CD-ROM. All novae were mapped
on an image of M31 using the GNU Image Manipulation Program (GIMP).
Light curves were graphed for all new major novae
(spanning more than a single epoch) and for previously discovered novae
which were found to exist in more epochs.
Conclusions
The pattern of distribution for Type NB novae has become
more apparent, as can be seen in the map. Novae which occur in only one
epoch seem to be clustered together in many places, suggesting some sort
of relationship.