Using Astroquery to Find Data

Astroquery is a convenient, programmatic way to filter all of MAST holdings and retrieve the data files you want.

Using it effectively means understanding how the TESS data is represented in the MAST Observations database (also known as the Common Archive Observation Model, CAOM).  All data at MAST is split into observations. Each of those observations have several data files associated with them.  Once you have the observation ID you will be able to then request a list of data products.  Thus most searches for MAST data through Astroquery require two filters, one on the observations level and one for the data products.  These tables provide useful information about those fields you might use to do those queries. Please see the CAOM field list and data products fields for the full list of filters.


FilterField NameHow it is used for TESS
Observation IDobs_id

FFIs: tess-s0001-4-2, where the 0001 is the sector, the 4 is the camera and 2 is the CCD

Postage stamp: the name is based on the file name and encodes the TIC ID and Sector Information.

Multi-sector DV: tess2018206190142-s0001-s0009-0000000141942911-00205, the range of the sectors searched and TIC ID is encoded

Fast-cadence or 20s data: tess2020186164531-s0027-0000000259886373-0189-a_fast

Proposal IDproposal_id

The Guest Investigator IDs are provided in this column. They are stored in a string with underscores separating them.

e.g. G011183_G011132_G011048_G011250

Sectorsequence_numberSector number is stored in this field as an integer. For multi-sector observations, the last sector of the search is stored.
Data Product Typedataproduct_type

FFI: "image"

postage-stamp: "timeseries"

Target Nametarget_name

postage-stamp: The integer TIC ID is given.

FFI: "TESS-FFI" is always the value.

Astroquery Example
#To get back all Observations containing TESS Mission light curves from sector 14 

from astroquery.mast import Observations
obs = Observations.query_criteria(obs_collection = 'TESS', sequence_number = [14], dataproduct_type = "timeseries")

#To get back 20-second, fast-cadence TESS Observations from sector 27
obs_fast = Observations.query_criteria(obs_collection = 'TESS', sequence_number = [27], t_exptime = [20], dataproduct_type = "timeseries")

Data Products Filter

FilterField NameHow it is used for TESS Data
Minimum Recommended Productmrp_only

When set to True you only get the most common data products. They are:

postage-stamp: light curve files and target pixel files.

FFI: There are no MRPs. 

Product Typeproduct_type

postage-stamp: "timeseries"

FFI: "image"


Choices are":

  • calibrated full frame images
  • uncalibrated full frame images
  • Light curves
  • Target pixel files
Data File TypeproductSubGroupDescription
  • FFIR - raw FFIs
  • FFIC - calibrated FFIs
  • TP - Target pixel files
  • LC - Light curves
  • DVR - Data validation report (includes pdf report and xml file)
  • DVS - Data validation summary
  • DVT - Data validation timeseries
  • DVM - Data validation mini report
  • FAST-TP - fast cadence target pixel files
  • FAST-LC - fast cadence light curve files

Common Problems when Using the MAST Portal for TESS

There are no FFIs in the basket to Download
  1. You must click on Minimum Recommended Products on the left. None of the FFIs are listed as a MRP.
  2. Consider downloading the FFIs through Bulk Downloads or the API.
I asked for a certain TIC ID, but it showed me products for a different part of the sky.You must include the catalog name when you do a cone search, i.e. "TIC 100100827". Otherwise your number may match another catalog, like the K2 EPIC Catalog. 
I find no data when I do a cone search at the center of the Camera's Field of View.The 4 CCDs per camera do not have continuous coverage.  If you add a fairly large radius to your cone search, you will then overlap all four CCDs.  For example, try Camera 4 by typing the following into the Portal's search box, 90.0042, -66.5647 r=2 d
Why are there two observations for the same Sector and TIC IDLikely the Pipeline found a TCE in a multi-sector data search. Multi-sector data get their own row in the MAST Portal. However, there are no lightcurve or target pixel files associated with that observation, only data validation products.

CasJobs Information

CasJobs is a great way to do a large, sql search on the TESS Input Catalog.  Here are the tables of interest once logged in.

TIC_v81/catalogRecordTESS Input Catalog v8.1
TIC_V81/catalogRecordV80Values290 rows as they appeared in TIC v8.0

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