Help With the Chart Search Engine
General
The database, when complete, is a combination of the AAVSO Chart Catalog,
the GCVS 4th edition (plus applicable name lists), Downes' living catalog
for many CVs, AAVSO bulletin info (for some visual range magnitudes), and some specific information
added by AAVSO staff. This database will be made public when completed.
The data displayed in the search engine may not match the data on the chart itself. This is because the chart uses data
that was current as of when it was published, whereas the search engine uses data that is (more or less) current as of 2001.
Please note that this database is not complete and will be slowly updated during
the first few months of 2002.
Designation
This is the Harvard Designation, as used by the AAVSO in our validation file. It is unique for every star and thus the best way to look for a specific chart.
Name
This is a name given by the star and used in our validation file. It generally consists of one or two capital letters (or greek letter) followed by the
3 character abbreviation of the constellation it lies in. Some notable exceptions are supernovae (typically SN XXXXYY where X is year and Y are letters denoting
the order it was discovered - SN 2001aa, SN 2001ab, etc.), unnamed novae (N XXX YY where XXX is the constellation and YY is the year - N CYG 01), suspected
variables (VAR XXX YY where XXX is the constellation and YY is the year discovered - VAR MON 02).
Type
The type generally follows the symbols established by the GCVS. Details can be found here.
Period
The period is generally based on the GCVS, Downes & Shara, etc.
Range
Most of these symbols were established by the GCVS.
In general:
| P | - | Photographic |
| V | - | Visual,
Photovisual, or Johnson V (if
following by 2 or
more figures after the decimal point) |
| 1 - 1.04 | - | micrometer band of the system
introduced by
G.W.Lockwood. |
| u,v,b,y | - | Stroemgren bands |
| Ic,Rc | - | Cousins I system |
| g | - | Thuan and Gunn system |
| T | - | broad-band Tycho formed from B and V
measurements |
| r | - | red magnitudes from no particular
system
|
See also the documents by Kholopov et al. (1985-1988) or Warren(1989).
Spectrum
Again, most of this comes from the GCVS. Here is a note in the GCVS4 documentation regarding
spectrum types:
Spectral types are reported in the MK system when
available. In cases where multiple types are
available, more recent classifications were generally
preferred, with some account being taken of
reliability if this was possible.
Comments
These are random comments, usually added by an AAVSO staff member. Cross referencing of charts
will also show up here, i.e. if the object you are looking for exists on a chart for another star
(because of close proximity) it will be mentioned here.
Charts
The mother load and why you are here! The chart scales are listed along with the file type. PostScript files are compressed
with PKZIP because of their size. Some new charts are in the PNG or JPG formats because we are moving away
from the GIF format (which is proprietary and costs us money to use). The PNG format is supported by
all web browsers and all relatively recent art programs. It was adopted as the new Internet standard in
graphics compression. JPG has been around for a long while and supported by everything.
Atlas Pages
This is the page number of the AAVSO Variable Star
Atlas on which this object exists.
Sequence Info
Help coming soon.