This routine is general purpose utility to list of selected elements from calibrated files.
munipack timeserie [...] file(s)
This utility is designed for listing of time series of a various quantities from a set of already processed frames. Instrumental and calibrated data can be used. Full calibrated data including astrometry and photometry calibration are preferred.
By listing of a set of processed files, this tool creates a time dependence of a required quantity. The quantity is selected as a FITS-table column name and stored in a time series table. The time series of a light-like quantity is referenced as a light curve (LC).
The utility can be used to derive various kinds of times-like quantities.
Needs astrometry and photometry. To get calibrated fluxes or magnitudes, needs photometry calibration.
On input, list of frames containing both astrometric and photometric information is expected.
On output, the FITS table representing the time series is created.
The time can be specified for reference points:
Following types of time can be specified (Julian day on wiki):
When -c or -C are not specified, the structure of the first file is discovered. The coordinates are recognised automatically as rectangular (equivalent to -C X,Y) or spherical (-C RA,DEC). All other columns (except coordinates) are listed by default (usually as -c COUNT,COUNTERR, -c PHOTON,PHOTONERR, -c MAG,MARERR, etc.).
By default, all stars on all frames are processed and stored to the output file. To select stars, there are two ways:
For a few stars request, the simpler way is specification of coordinates on the command line. Use twices of equatorial coordinates (Right Ascension and Declination) in degrees separated by commas (or semicolon). For example:
$ munipack timeseries 330.689,42.2765 330.667,42.2860 file.fits
More general way is use of a table with coordinates. Important advantages over command line:
The proper motion can be important for near and moving stars and should by used for flying rocks.
Format of the catalogue is very restrictive and must be carefully
followed. One is stored in FITS file with a just one table extension
(EXTNAME doesn't matter). The header must contain keyword EPOCH which
denotes the reference time t0 in Julian days for object coordinates.
The current positions at t are computed from reference coordinates
α0, δ0
and proper motions μα0, μδ0 (in
degrees per century) as:
α = α0 + μα0 /(t - t0) / T
δ = δ0 + μδ0 /(t - t0) / T
where T is the time unit given by TUNITS keywords in header.
One is one for deg/day and 365.25 for arcsec/year.
The most simple way how to create the catalogue, timeserie_cat.lst can be directly used as example and edited. The FITS file timeserie_cat.fits is created as
$ munipack fits --restore timeserie_cat.lst
Column | Description | Units |
---|---|---|
RA | Right ascension α0 | degrees |
DEC | Declination δ0 | degrees |
pmRA | proper motion in RA μα0 | arcsec/year or deg/day[†] |
pmDEC | proper motion in DEC μδ0 | arcsec/year or deg/day[†] |
This utility is primary indented and designed for working with low amount of data. The typical usage is listing of light curves or positions of motion of objects during a night. Another example can be study of any instrumental quantity. This routine is generic analysing tool.
Use on large archives of observations is not recommended. Spidering over a complicated directory structure would be really slow. To work with a large data archive, use Munipack to create tables with photometry and astrometry data and keep the results in a database. Much more better idea should be to import the data into some Virtual Observatory engine. Popular VO-engines are VO-Dance, Saada or GAVO DaCHS.
Timeseries for all stars:
$ munipack timeseries M67_Blue.fits
Light curve for stars at coordinates:
$ munipack timeseries 256,156 258,88 0716_*R.fits
Data format for timeseries, Light Curve Tutorial, Common options.