# Light curve files

Light curves (dependency of brightness on observation time) are usually final product of the reduction process. A light curve table consists of observation time in Julian date form followed by magnitudes and their errors of all selected stars. Two basic output working modes are provided: in differential mode, magnitudes stored in the table are differences between each pair of the stars. On the other hand, instrumental mode allows you to print out raw values computed by photometry. Note, that instrumental magnitudes cannot be compared to absolute ones, which is found in the photometry catalogs, without further post-processing.

Format C-Munipack (default)

Output files are stored in the ASCII format; the end of the line is represented by `CR+LF` in the DOS/MS Windows environment and by `LF` in the Unix/Linux environment. First line contains always a list of column names separated by single space character. Second line consists of additional information (aperture, filter, etc.) and has no special formatting, it must not start by number, though.

On the following lines, the table values are stored. The values are separated by tab character or single space, rows are separated by the end-of-line character (see above). Parsers must ignore all additional white characters. Empty lines indicates, that the corresponding frame was not successfully processed and thus a brightness of a variable or a comparison star could not be determined. See table 1 for short description of columns.

Table 1

Keyword | Description
--- | ---
JD | Geocentric Julian date of observation
JDHEL | Heliocentric Julian date of observation
V-C | Difference of variable and comparison star
s1 | Error of V-C value
V-K1 | Difference of comparison and check star #1
s2 | Error of C-C1 value
… | …
V | Brightness of variable star (abs. instr. magnitude)
s1 | Error of V value
C | Brightness of comparison star
s2 | Error of C value
K1 | Brightness of check star #1
s3 | Error of K1 value
… | …
IDnnn-C | Difference of object with ID nnn and the comparison star
… | …
IDnnn | Brightness of object with ID nnn (abs. instr. magnitude)
… | …
HELCOR | Heliocentric correction in days
AIRMASS | Air mass coefficient
ALTITUDE | Altitude (elevation) in degrees above horizon

Format AVE compatible

The “AVE compatible” file format allows to save a light curve with differential magnitudes to the AVE software [barbera11]. The output file is an ASCII text file. Each frame is stored on a separate line, lines begin with a Julian date of observation, followed by a space and followed by a brightness of a variable star in magnitudes. Frames where a variable was not measured are omitted. The file does not contain any header.

Format MCV compatible

The “MCV compatible” file format allows to save instrumental magnitudes of selected stars in a file that can be processed in the MCV software [andronov04]. The output file is an ASCII text file. Each frame is stored on a separate line, lines begin with a Julian date of observation, followed by instrumental magnitude for each selected star. Fields are separated by a space character. A zero value stored instead of a valid magnitude indicates missing or invalid data. The file does not have any header.

See also

Light curve, Light curve (dialog), Export light curve in AAVSO format