Description of FITS tables intended for store of time series (light curves) or another time series data.
The table is created as output of munipack timeseries command.
The specification slightly follows SimpleTimeseries format (IMPORTANT: This link is intentionally dead due authors themselves. There is no widely accepted definition of a format for light curves and related affairs yet.) Generally, Munipack's format is a bit more simplified and restrictive.
| HDU | EXTNAME | Description |
|---|---|---|
| 0 | Dummy[โ ] | |
| 1 | TIMESERIES | Time Series Table |
| 2 | CATALOGUE | Objects identification (coordinates) |
[โ ] The first dummy extension contains keywords of identification HDUNAME, which is set mandatory to 'TIMESERIES', CREATURE is set to 'Munipack X.Y.Z' version and a link to this page as a comment.
The main table which stores the time series.
| Keyword | Value | Default | Description |
|---|---|---|---|
| EXTNAME | TIMESERIES | TIMESERIES | extension identifier |
| TIMETYPE | JD | JD | Type of TIME: JD (Julian Day), MJD (modified JD), HJD (heliocentric JD), phase ฯ[1] |
| TIMESYS | UTC | UTC | Time system |
| TIMEREF | GEOCENTRIC | Reference time point | |
| TIMESTMP | MIDPOINT | MIDPOINT | time stamp = MIDPOINT,BEGIN,END[2] |
[1] Definition of Julian (also other derived) days provides Julian day wiki page. The phase ฯ = {(t - t0)/P} is defined as fractional part ({x} = x - โxโ) of time difference HJD since the epoch t0 per period P.
[2] The time is labeled by timestamps (the elapsed time is T): at the begin t0 (BEGIN) up to finish t1 = t0 + T (END) time. The midpoint is computed as t0 + T/2.
| Column | Type | Description |
|---|---|---|
| TIME | 1D | Time-like quantity[a] |
| EXPTIME | 1D | Integration time like quantity[b] |
| Qi | 1D | Quantity for i-th object[c] |
| QEi | 1D | Standard deviation of Q-i[c] |
[a] Units of the time-like quantity in days (for H,M,JD). The phase has no units.
[b] The exposure time is directly copied from frames and units are (perhaps) seconds.
[c] Table can contain many physical quantities. For their meaning, see Photometry data table. The table can contains multiple columns of the quantities for all required objects.
This extension contains equatorial coordinates of objects of TIMESERIES extension.
| Keyword | Value | Default | Description |
|---|---|---|---|
| EXTNAME | CATALOGUE | CATALOGUE | extension identifier |
| REFRAME | ICRS | Reference celestial coordinate system | |
| EPOCH | 2000 | Reference epoch for proper motion |
| Column | Type | Description | Units |
|---|---|---|---|
| RAJ2000 | 1D | Right Ascension[ยง] | degrees |
| DEJ2000 | 1D | Declination[ยง] | degrees |
[ยง] Coordinates are referenced for epoch of the observation. Fast-moving objects can evince visible coordinate differences.