Mission Overview
A PSF-Based Approach to TESS High Quality Data Of Stellar Clusters (PATHOS)
Primary Investigator: Domenico Nardiello
HLSP Authors: Domenico Nardiello
Released: 2019-10-09
Updated: 2019-10-09
Primary Reference(s): Nardiello et al. 2019
Citations: See ADS Statistics
Overview
The PATHOS project provides a database of high-precision light curves for members of stellar clusters, obtained by extracting photometry from TESS Full Frame Images. Light curves are obtained with an innovative PSF-based approach, that involves the use of empirical Point Spread Functions (PSFs), a high-angular resolution input catalogue (Gaia DR2) and neighbor-subtraction. The PSF-based approach minimises the dilution effects in crowded environments, enabling extraction of high-precision photometry for stars in the faint regime (T > 13). The PATHOS database contains all the light curves extracted during the project, as well as light curves requested for other projects. Light curves of specific targets can be requested by contacting the project managers.
The first release contains light curves for targets in Sector 1 only.
Data Products
Each target has a FITS and TXT version of the light curves available. The files are stored in sub-directories based on the Sector they are in as a 4-digit, zero-padded number, e.g., "s0001/" for Sector 1. The data file naming convention is:
hlsp_pathos_tess_lightcurve_tic-<ticid>-<sector>_tess_v1_<ext>
where:
- <ticid> = The 10-digit, zero-padded TIC ID of the target
- <sector> = The Sector number as a 4-digit, zero-padded value, e.g., "s0001" for Sector 1
- <ext> = The data file type extension
Data file types:
| _llc.fits | The light curve file in FITS format. |
| _llc.txt | The light curve file in TEXT format. |
The available columns include the raw fluxes from the PSF-based approach and four different aperture sizes (PSF_FLUX_RAW, AP{1,2,3,4}_FLUX_RAW) and the corrected fluxes (PSF_FLUX_COR, AP{1,2,3,4}_FLUX_COR). The TIME column is in barycentric-corrected, truncated TESS Julian Date (BJD - 2457000.0).
Data Access
PATHOS data products are available in the MAST Portal and astroquery.mast. For those who want to download all the light curves for a given Sector, the following Python code example below will query for all the available PATHOS observations for a given Sector (should take a few minutes) and then download the light curve FITS files. NOTE: There are tens of thousands of light curves for a given Sector, thus downloading all of the products can take the better part of a day, even with good internet connections. By default, the light curve files will be downloaded under a folder called "mastDownload" in the same working directory that your run the Python script from.
from astroquery.mast import Observations
sector_num = '1'
print('Querying for PATHOS Sector ' + sector_num + " Observations...")
obsTable = Observations.query_criteria(provenance_name = "PATHOS",
sequence_number = sector_num)
print("Found a total of " + str(len(obsTable)) + " PATHOS targets.")
print('Downloading data products for these observations...')
for obs in obsTable:
data_products = Observations.get_product_list(obs)
Observations.download_products(data_products)
