Data Columns in the UKIRT Light Curves Table
The NASA Exoplanet Archive provides access to the public data for the UKIRT microlensing survey.
See the UKIRT Summary page for more information on the UKIRT data products available at the NASA Exoplanet Archive.
This page describes all of the parameters displayed in the UKIRT Time Series table (ukirttimeseries) and that can be returned through the Exoplanet Archive's Table Access Protocol (TAP) service. For more information on UKIRT light curve statistics, refer to the UKIRT Processing page.
If you use archive data or services for your research, please include the following Digital Object Identifier (DOI) as part of your acknowledgment:
DOI 10.26133/NEA7
See Acknowledging the Archive for dataset-specific language. See the full list of NASA Exoplanet Archive DOIs for other data sets and services.
If you have questions about the structure or use of this table in the archive format, submit a Helpdesk ticket.
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Stellar Columns
| Database Column Name | Table Label | Description |
|---|---|---|
| sourceid | Source ID |
Long-form ID specifiying Photometry Method, Survey Year,
Galactic Bulge Region, Field ID, CCD ID, and Index of
unique UKIRT light curve.
Example: ukirt_c_2016_s_33_1_0065104 |
| obs_year | Survey Year | UKIRT microlensing survey year (2015–2019) |
| bulge | Galactic Bulge Region |
Galactic bulge region:
|
| field | Field ID |
UKIRT microlensing survey field ids, which are numbered as such:
For more coverage information, see the UKIRT Coverage Maps and Magnitude Ranges page. |
| ccdid | CCD ID | UKIRT microlensing survey CCD number, within a given field (Range: 1–4) |
| ra | RA [decimal degrees] | Right Ascension corresponding to light curve, in decimal degrees |
| dec | Dec [decimal degrees] | Declination corresponding to light curve, in decimal degrees |
| hjdstart | Start HJD [days] |
Date of first point in light curve; the time system is the number of days since the Reference HJD (i.e., HJD - 2450000) |
| hjdstop | End HJD [days] | Date of last point in light curve; the time system is the number of days since the Reference HJD (i.e., HJD - 2450000) |
| hjd_ref | Reference HJD [days] | Reference HJD for hjdstart and hjdstop database entries (HJD = 2450000) |
| h_mag | H-band [mag] | Mean H-band magnitude of light curve |
| k_mag | K-band [mag] | Mean K-band magnitude of light curve |
| npts | Points in Light Curve | Number of data points in light curve (i.e., number of epochs that are not "null") |
Microlensing Survey Catalogs
| Database Column Name | Table Label | Description |
|---|---|---|
| k2c9_flag | K2 Campaign 9 Field Overlap Flag | Binary flag indicating whether given light curve was observed by K2 during its Campaign 9 microlensing survey (1 = yes; 0 = no) |
| ukirt_evt_flag | UKIRT Event Flag | Binary flag indicating whether given light curve was identified as a possible microlensing event by the UKIRT Microlensing Team event detection pipeline (1 = yes; 0 = no) |
| ukirt_id | UKIRT Event ID | UKIRT microlensing event ID (Null unless UKIRT Event Flag = 1) |
| ogle_evt_flag | OGLE Event Flag | Binary flag indicating whether given light curve matches to a microlensing event identified by the OGLE-IV Early Warning System for the corresponding survey year (1 = yes; 0 = no) |
| ogle_id | OGLE Event ID | OGLE-IV microlensing event ID (Null unless OGLE Event Flag = 1) |
| moa_evt_flag | MOA Event Flag | Binary flag indicating whether given light curve matches to a microlensing event identified by the MOA-II Transient Alert for the corresponding survey year (1 = yes; 0 = no) |
| moa_id | MOA Event ID | MOA-II microlensing event ID (Null unless MOA Event Flag = 1) |
Magnitude Statistics
These parameters are for a standard set of time series statistics performed on each light curve.
| Database Column Name | Table Label | Description |
|---|---|---|
| statnpts | Points in Statistics Calculation | Number of points used in statistics calculations |
| minvalue | Minimum Value of Light Curve [mag] | Minimum magnitude value of light curve (i.e., the brightest data point) |
| maxvalue | Maximum Value of Light Curve [mag] | Maximum magnitude value of light curve (i.e., the faintest data point) |
| mean | Mean Value of Light Curve [mag] | Mean magnitude value of light curve |
| stddevwrtmean | Std Dev of Light Curve wrt Mean [mag] | Standard deviation with respect to mean magnitude of light curve |
| median | Median of Light Curve [mag] | Median magnitude value of light curve |
| stddevwrtmed | Std Dev of Light Curve wrt Median [mag] | Standard deviation with respect to median magnitude of light curve |
| n5sigma | Number of Points > 5 Sigma from Median | Number of points further than 5 standard deviations from the light curve median magnitude |
| f5sigma | Fraction of Points > 5 Sigma from Median | Fraction of points further than 5 standard deviations from the light curve median magnitude |
| medabsdev | Median Absolute Deviation of Light Curve [mag] |
Median absolute deviation of light curve |
| chisquared | Reduced Chi-squared of Light Curve | Reduced chi-squared of light curve with respect to the median magnitude |
| range595 | 5–95% Range of Light Curve [mag] | 5–95 percentile range of light curve |
Last updated: 1 March 2022
