Data Columns in the UKIRT Light Curves Table

The NASA Exoplanet Archive provides access to the public data for the ongoing 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 (2015–2018)
bulge Galactic Bulge Region

Galactic bulge region:

  • central [specified target fields of 2017–2018 surveys], or
  • northern [2015 survey and specified target fields of 2017–2018 surveys], or
  • southern [2016 survey and specified target fields of 2017–2018 surveys].
field Field ID

UKIRT microlensing survey field ids, which are numbered as such:

  • 2015: 11–14; 21–24; 31–34; 41–44; 5; 6
  • 2016: 11–14; 21–24; 31–34; 41–44; 51–54; 61–64; 71–74; 81–84
  • 2017–2018:
    • central: 11–14; 21–24; 31–34; 41–41
    • northern: 11–14; 21–24; 31–34; 41–41
    • southern: 11–14; 21–24; 31–34; 41–41; 51–54; 61–64

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: 13 July 2021