Summary details for HATNet Exoplanet Archive-ETSS Data Sets


The Hungarian-made Automated Telescope Network (HATNet), consisting of 7 11.0cm telescopes located at Fred Lawrence Whipple Observatory (Arizona), Mauna Kea Observatory (Hawaii), and Wise Observatory (Israel).


Prior to 2007 September each telescope employed a 2K x 2K CCD and a Cousins I_C filter. The 2K x 2K CCDs covered an 8.2° x 8.2° field of view at a pixel scale of 14". After this date the telescopes were refitted with 4K x 4K CCDs and Cousins R_C filters. The new CCDs cover a 10.6° x 10.6° field of view at a pixel scale of 9".

Observed Region

The data for this survey comes from 72 HATNet fields with declinations between +15 degrees and +52 degrees. These fields are defined by dividing the sky into 838 7.5° x 7.5° tiles. The survey covers approximately 4000 square degrees, or roughly 10% of the sky.

Photometric Technique

Both aperture photometry (AP) and image subtraction photometry (ISM) have been used for reductions. Photometry is performed at the positions of 2MASS sources transformed to the image coordinate system. For each resulting light curve the median magnitude is fixed to the I_C or R_C magnitude of the source based on a transformation from the 2MASS J,H and K_S magnitudes. For the ISM reduction this magnitude is also used as the reference magnitude for each source in converting differential flux measurements into magnitudes. For each source, light curves are obtained using three separate apertures. The aperture radii used are 1.45, 1.95, and 2.35 pixels.

Detrending Technique

The calibrated light curves for each aperture are passed through two routines that remove systematic variations from the light curves that are not corrected in calibrating the ensemble. The first routine (EPD) decorrelates each light curve against a set of external parameters. After applying EPD, the light curves 4 Hartman et al. are then processed with the Trend-Filtering Algorithm (TFA) which decorrelates each light curve against a representative sample of other light curves from the field.

Data Ranges

The data parameters fall into the following approximate ranges:

Field Min Max
HJD of the
2452910.713 2454906.647
J 2MASS magnitude 2.735 13.577
H 2MASS magnitude 2.735 12.967
K 2MASS magnitude 2.636 12.812
B Johnson magnitude 2.780 99.990
V Johnson magnitude 2.870 17.870
I Cousins magnitude 2.880 99.990
Total number of stars - 2656
Number of epochs 1087 11601

Download Data Sets

HATNet summary file IPAC ASCII format table
HATNet light curves Download scripts

Primary References