Winter 2021 Space Telescope Science Institute
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Winter 2021 Space Telescope Science Institute
3700 San Martin Drive
Baltimore, MD 21218
https://archive.stsci.edu
facebook.com/MASTArchive
DATA ACCESS @MAST_News
archive.stsci.edu/access-mast-data
Winter 2021
How to Access MAST Data
There are many ways to search for and retrieve MAST data. You can use the Portal search engine, one of our APIs for programmatic
access, or use the Virtual Observatory to download data from many astronomy data services. For links to all of these services, check out:
archive.stsci.edu/access-mast-data
Search with MAST API Suite
Astroquery – A streamlined interface for Python users to access data in MAST. Replicates most functions of the MAST Portal web interface.
Access MAST queries using the same function conventions and return types available for all Astroquery services. Integrate easily with Astropy
functionality and other Python analysis tools.
Webservice API – Programmatic access to MAST data through HTTPS requests. The most direct way to programmatically access data in MAST,
it is language agnostic, requiring only the ability to send/receive HTTPS requests.
Classic API – Search MAST using HTTP GET requests. The results can be returned in a variety of formats including HTML, VOTable XML format,
Excel spreadsheet, and comma-separated values, which can simplify ingesting results into user-written programs.
Search with MAST Search Websites
MAST Portal –The MAST Portal lets you search multiple collections of astronomical data-sets from one
place. Use this tool to find astronomical data, including images, spectra, catalogs, timeseries, publication
records and more.
Virtual Observatory (VO) – The Virtual Observatory (VO) seamlessly incorporates astronomical data from active missions, archives, and
other institutional resources worldwide.
exo.MAST – Search by exoplanet name to find data, parameters, visualizations, and MAST holdings like
Kepler, K2, Hubble, TESS and JWST. Easily find the data taken during the transit, interact with folded light
curves, and view or download published spectroscopy.
Mission Specific Search Forms – MAST provides web forms to search for data from individual missions.
MAST CASJobs – A website for running SQL queries on MAST catalogs and tables. Long and complex que-ries are supported, and users can
store the output in a user database.
HLSP Search – HLSPs are observations, catalogs, or models that complement, or are derived from,
MAST-supported missions. They can include images, spectra, light curves, maps, source catalogs,
simulations, observations from other telescopes, or data that have been processed in a way that differs
from what’s available in the originating archive.
Catalogs – Catalogs.MAST provides access to tabular measurements of astronomical objects from the
Hubble Space Telescope and other missions.
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MAST NOTEBOOKS @MAST_News
spacetelescope.github.io/notebooks
Winter 2021
MAST Notebooks and Tutorials
We have prepared a curated collection of Jupyter notebooks that teach users to query and analyze a wide variety of MAST data. The notebooks are
designed to be easy to follow for both beginners and more advanced users. Tutorial difficulty is clearly marked. Each notebook demonstrates the
final outcome up-front, and then takes users through a step-by-step explanation of how to achieve the results.
Notebooks demonstrate use of: Many missions are represented:
• Astroquery Observations to download MAST data • Exoplanet Survey Satellite (TESS)
• Astroquery Catalogs to filter MAST catalogs • Kepler
• K2
• TESScut to get parts of the TESS FFIs
• Panoramic Survey Telescope and Rapid Response
• TAP protocols to explore MAST catalogs System (PanSTARRS)
• Astropy FITS file handling • Hubble Source Catalog (HSC)
• DrizzlePac usage • James Webb Space Telescope (JWST)
Rendered versions of the notebooks for web viewing: The notebooks repository for downloading:
spacetelescope.github.io/notebooks/ github.com/spacetelescope/notebooks
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JWST @MAST_News
mast.stsci.edu
Winter 2021
JWST Planned Observations Available In Mast Portal
Gto and dd-ers programs that have been accepted for jwst are now visible in the Mast Portal. This includes instrument and filter infor-
mation, as well as initial footprint plotting.
MAST has added a new feature to the Data Discovery Portal, which allows users to search for planned JWST observations, including those requested
in Guaranteed Time Observation (GTO) programs and Director’s Discretionary Early Release Science (DD-ERS) programs. As with other Portal queries,
users are able to cross-match these results with other STScI missions, to explore what data are already available for the targets and fields in question.
The Portal can help with JWST duplication checking. Observations that duplicate planned GTO or ERS observations must be justified scientifically.
To avoid unintentional duplications, JWST investigators will be required to check their proposed observations against those already approved. The
Portal offers a convenient way to identify potential duplications of targets before submitting a JWST proposal, but it does not offer a complete
specification of planned observations. Any potentially duplicate targets should therefore still be inspected in detail by downloading the approved
APT file for the relevant programs using the program information tool (https://jwst.stsci.edu/observing-programs/program-information). The
final responsibility for duplication checking rests with each proposer.
Planned observations are designated in the MAST Discovery Portal with a calibration level of -1 (currently exclusive to JWST programs). Users may
combine a filter on this parameter with any other available constraints, such as position or instrument, in an advanced search. The ‘Proposal ID’ field
in the search results table also provides an active link to the program information page, so users may access APT files and additional information
on any programs that turn up in their queries.
MAST Discovery Portal access to JWST planned observations also means that these programs are visible through the MAST API as well. Some
examples of querying JWST planned observations using Python are available on GitHub (https://github.com/spacetelescope/JWST_Planned_
Observations), and additional API examples and tutorials are available on the MAST API documentation pages (https://mast.stsci.edu/api/v0/).
Additional information on duplication checking and the duplication policy for JWST may be found on JDox (https://jwst-docs.stsci.edu). Further
questions or comments on finding planned JWST observations in the MAST Portal may be directed to archive@stsci.edu or to the new Archive
Helpdesk (https://stsci.service-now.com/mast).
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TESS @MAST_News
archive.stsci.edu/tess
National Aeronautics and Space Administration
Winter 2021
About the TESS Mission
The Transiting Exoplanet Survey Satellite (TESS) is an all-sky transit survey, whose
principal goal is to detect Earth-sized planets orbiting bright stars that are amenable
to follow-up observations to determine planet masses and atmospheric compositions.
TESS conducts high-precision photometry of more than 200,000 stars during a two-
year mission with a two-minute cadence, and a subset of targets with 20-second
cadence. These targets are read-out as postage stamps and are made available to
TRANSITING EXOPLANET SURVEY SATELLITE
Discovering New Earths and Super-Earths in the Solar Neighborhood
the community as target pixel files (TPFs) and calibrated light curves. In addition,
the full image frames are read out approximately every 10 minutes starting with
www.nasa.gov Sector 27. These Full Frame Images (FFIs) enable users to conduct photometry
on any target within the 24x96 degree field-of-view. Data validation products are
provided for astrophysical signals that are found by the TESS team. The extended
TESS mission began in summer 2020 with Sector 27, the first data release of the
TESS Litho_Sep2015.indd 1
extended mission was in September 2020. 9/15/15 3:37 PM
The TESS Input Catalog (TIC) was released in June 2017, and has been updated a
few times since then. The final version, version 8, was released in 2019. The TIC is a
catalog of every optically luminous, persistent object in the sky that extends down to
the limiting magnitudes of its component catalogs. It contains approximately 1.7 billion
objects, and includes catalog information from Gaia, 2MASS, SDSS, ALLWISE, APASS,
Tycho-2, UCAC4, LAMOST, RAVE, APOGEE, KIC and EPIC. The TIC allows users to:
1. Look-up information, including coordinates and stellar properties, for any target
the TESS mission produces a light curve of.
2. Enable selection of the planet search stars, which includes consideration of
background flux contamination levels.
3. Provide stellar parameters, such as stellar radii, which the processing pipeline
uses when calculating planet properties.
4. Facilitate false positive detection, including background sources.
A complete list of data products is available on the MAST TESS homepage.
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TESS @MAST_News
archive.stsci.edu/tess
Winter 2021
Summary Of TESS Search and Retrieval Tools at MAST
Portal
https://mast.stsci.edu
• Download light curves, target pixel, and data validation files for a few targets.
• Download full frame images for a few CCDs.
• Conduct small searches within the TIC or CTL.
• Find data from other missions for your target.
exo.MAST
exo.mast.stsci.edu
• Find MAST data (including TESS) for known planets, TOIs, or threshold crossing events (TCEs),
matched to orbital phase.
• Plot sector-stitched DV light curves.
• Access to exoplanet parameters, with references, from NExScI or exoplanets.org
• Get plots of observability windows with NIRISS on JWST for planning purposes.
Bulk Downloads
https://archive.stsci.edu/tess/bulk_downloads.html
• Download all light curves / target pixel files for a given sector.
• Download all light curves / target pixel files for a given GI program.
• Download all full frame images for a given sector.
• Download the entire TCE table.
• Download the current TIC and CTL.
API / astroquery
mast.stsci.edu/api/v0/
https://astroquery.readthedocs.io/en/latest/mast/mast.html
• Search for, and retrieve, TESS data products programmatically based on a list of coordinates or
target names.
• Interact with observational data, TIC, and CTL catalogs in programs you write.
TESSCut
mast.stsci.edu/tesscut/
https://astroquery.readthedocs.io/en/latest/mast/mast.html#tesscut
• Create time series pixel cutouts from the TESS full frame images.
• Find out what sectors/cameras/detectors a target was observed in.
Archive Manual
https://outerspace.stsci.edu/display/TESS/TESS+Archive+Manual
• Step-by-step instructions on how to use MAST web interfaces for TESS.
• Get Python notebook tutorials on using TESS data and MAST tools.
• Access the TIC and CTL “live” release notes.
• Learn how to contribute TESS-related data products to MAST.
HIGH LEVEL SCIENCE facebook.com/MASTArchive
@MAST_News
PRODUCTS
archive.stsci.edu/hlsp
Winter 2021
High Level Science Products (HLSPs) are observations, catalogs, or models that complement, or are derived from, MAST-supported
missions. These include Hubble, James Webb, Kepler/K2, GALEX, TESS, Swift, XMM, PanSTARRS, and others. HLSPs can include images,
spectra, light curves, maps, source catalogs, or simulations. They can include observations from other telescopes, or MAST data that have been
processed in a way that differs from what’s available in the archive. HLSPs are permanently archived at MAST, get their own project webpage,
and will appear in MAST search interfaces along with bibliographic references to your paper(s). A list of existing HLSP is available through a new
search form: https://archive.stsci.edu/hlsp/.
Contribute Your Data
If you are interested in contributing an HLSP to MAST, we encourage you to let us know as early as possible using the new web form at https://
archive.stsci.edu/hlsp/interest/. Fill out as much information as you have, and skip the manuscript section if there is not a paper nearing
submission or publication. MAST will work with you to ingest your data and provide you with a Digital Object Identifier (DOI) to use in papers to
provide a durable link to your HLSP. You can find our HLSP guidelines here: https://archive.stsci.edu/hlsp/hlsp_guidelines/index.html
TESS-SPOC + QLP
TESS-SPOC is a collection of light curves for up to 160,000 targets from each Sector using the TESS Full
Frame Images (more than 1 million total from Sectors 14-26). Light curves, target pixel, and co-trending
basis vector files are provided. QLP is a collection of more than 24 million de-trended light curves from
the MIT Quick Look Pipeline based on TESS Full Frame Images. Light curves are provided in both FITS
and text format. https://archive.stsci.edu/hlsp/tess-spoc and https://archive.stsci.edu/hlsp/qlp
ULLYSES
ULLYSES is a Director’s Discretionary program devoting ~1,000 HST orbits to the production of an
ultraviolet spectroscopic library of young high- and low-mass stars in the local universe over the next
three years. The data products are combined from individual, extracted and calibrated spectra obtained
with the COS and STIS instruments on-board HST. Products are made using both archival HST data
and new HST observations obtained through the ULLYSES program. The first data release consists
of multiple spectra for 115 massive stars in the Large and Small Magellanic Clouds. 43 of these 115
stars were recently observed with COS and STIS as part of the ULLYSES program; 8 of these 43 also
have archival COS and STIS data. https://archive.stsci.edu/hlsp/ullyses
PS1-STRM
PS1-STRM is a neural network source classification and photometric redshift catalog of nearly three
billion objects from the PanSTARRS 3PI DR1. The networks are trained on a compilation of spec-
troscopic measurements cross-matched with PS1, sources are classified as galaxy, star, quasar, or
unsure. https://archive.stsci.edu/hlsp/ps1-strm
GUVCat
GUVCat is composed of catalogs of clean, unique (i.e. only one entry for each object) UV sources from
GALEX, useful to estimate density of sources across the sky or the number of sources with given
magnitude or color ranges, or to match UV sources with other catalogs. The HLSP team have also
cross-matched their GUVCat unique source catalog to SDSS DR14 and Gaia DR2, making those tables
available as HLSP catalogs as well. GUVcat is composed using tiles from the AIS (All-Sky Imaging
Survey), with a depth of about 19.9/20.8 in FUV/NUV ABmag. https://archive.stsci.edu/hlsp/guvcat
HIGH LEVEL SCIENCE facebook.com/MASTArchive
@MAST_News
PRODUCTS
archive.stsci.edu/hlsp
Winter 2021
stella
stella is a novel way to detect flares in TESS short cadence data using convolutional neural networks
(CNNs). Any TESS short cadence light curve can be run through the CNN models provided, without
any detrending. The models created by the team return a probability light curve (see example figure),
with values between 0-1 if a given light curve event is a flare or not. It takes < 1 minute to predict
flares on a single TESS sector light curve using these models. https://archive.stsci.edu/hlsp/stella
PHATAGB
PHATAGB consists of a catalog of 937 candidate asymptotic giant branch (AGB) stars in M31 star
clusters from the Panchromatic Hubble Andromeda Treasury survey, together with their finding charts.
The photometric criteria selects stars brighter than the tip of the red giant branch, which includes the
bulk of the thermally pulsing AGB stars as well as early-AGB stars and other luminous cool giants
expected in young stellar populations (e.g., massive red supergiants, and intermediate-mass red
helium-burning stars). The AGB stars can be differentiated using the ages estimated for the clusters.
Cross-matching with additional databases reveals two carbon stars and 10 secure variables among
them. https://archive.stsci.edu/hlsp/phatagb
UVESCAPE
The UVESCAPE team has demonstrated a new method for measuring the escape fraction of ionizing
photons using HST imaging of resolved stars in NGC 4214, a local analog of high-z starburst galaxies
that are thought to be responsible for cosmic reionization. They forward model the UV through near-IR
spectral energy distributions of ~83,000 resolved stars to infer their individual ionizing flux outputs
using the Bayesian Extinction And Stellar Tool (BEAST; Gordon et al. 2016). They constrain the local
escape fraction by comparing the number of ionizing photons produced by stars to the number that
are either absorbed by dust or consumed by ionizing the surrounding neutral hydrogen in individual
star-forming regions. The team has made their catalog of stellar ionizing fluxes available as a High
Level Science Product. https://archive.stsci.edu/hlsp/uvescape
HAZMAT
The HAbitable Zones and M dwarf Activity across Time (HAZMAT) program assesses the lifetime
exposure of planets to stellar ultraviolet (UV) radiation using GALEX data, HST COS and STIS spectra,
and semi-empirical, full-wavelength models. The data products consist of high-resolution synthetic
spectra (EUV – IR; 100 Angstroms to 5.5 microns) of early-M stars at five distinct ages between 10
Myr and 5 Gyr. The spectra are computed with the PHOENIX atmosphere code from one-dimensional
upper atmosphere models of 0.35 and 0.45 solar mass stars. Downloadable data products include five
spectra per 0.35 and 0.45 solar mass stars at ages of 10, 45, 120, 650, and 5000 Myr. Models for
TRAPPIST-1, GJ 832, GJ 176, and GJ 436 are also available. https://archive.stsci.edu/hlsp/hazmat
ExoMAST
facebook.com/MASTArchive
@MAST_News
exo.mast.stsci.edu
Winter 2021
exo.mast.stsci.edu
API exo.mast.stsci.edu/api/v0.1/doc
A fast, easy way to find exoplanet data from TESS, Kepler, K2, Hubble & soon JWST
Find & download exoplanet parameters, data visualizations & MAST holdings by exoplanet. Easily find the data
taken during the transit. Links to exoCTK to help with JWST observation planning
Interact with folded light curves. Find planets for atmospheric characterization at:
catalogs.stsci.edu/eaot
MAST CATALOGS facebook.com/MASTArchive
INTERFACE @MAST_News
https://catalogs.mast.stsci.edu
Winter 2021
The MAST Catalogs Interface provides a simple but powerful tool for accessing MAST catalogs,
including both a web user interface and an underlying API for access from scripts. Currently it
includes the Pan-STARRS1 database, the Hubble Source Catalog (including the Hubble Catalog
of Variables), and the Exoplanet Atmosphere Observability Table. It implements a common, easily
learned interface design for different catalogs. Catalog searches rely on an underlying API that is
well documented and is directly accessible via scripting languages such as Python.
The Pan-STARRS1 Catalog Interface
The Pan-STARRS1 (PS1) catalog has a simple web-based user interface that provides:
1. A name-resolver to search at a sky position 5.Built-in documentation and tool tips for the catalog fields
2. T he option to upload a list of targets specified by position or name 6. a customizable choice of which columns to display,
3. The ability to search multiple releases of the catalogs 7. the ability to apply constraints using any of the catalog columns
4. Access to multiple tables within those releases 8. an interface that remembers those customizations
For PS1, both the DR1 and DR2 releases are available, and in the DR2 release one can search the detection table (single-epoch measurements), the
mean object table (averages of the detection values), the stacked object table (measurements from the stacked images), and forced mean object
table (photometry on the single-epoch images for objects detected in the deeper stacked images).
The search results page has many useful features, including the ability to sort by any column and a link to download the table as comma-separated
values (1). In PS1 the objID column for the mean object results is a clickable link (2) that takes you to all the detection info for that column (the multi-
color light curve for the object). Since the search parameters are saved, you can go back to the search page and refine the parameters if desired.
Finally, the API documentation link (3) takes you to a page that describes the scriptable API interface, which can be used for large and repeated
queries of the catalog. The API is also accessible via the astroquery.mast module. See our Python Jupyter notebook for an easily adapted
example of PS1 queries (https://ps1images.stsci.edu/ps1_dr2_api.html). The figure shows the PS1 DR2 light curve for an eclipsing binary
generated by the notebook.MAST CATALOGS facebook.com/MASTArchive
@MAST_News
INTERFACE
https://catalogs.mast.stsci.edu
Winter 2021
Light curve for eclipsing binary KIC 8153568, generating by querying the MAST catalogs API.
The Hubble Source Catalog interface
The Hubble Source Catalog (HSC) has a very
similar interface. It includes access to both the
HSC summary catalog (with mean multi-filter
measurements, similar to the PS1 mean objects)
and the HSC detailed table (with single-epoch
measurements, similar to the PS1 detection table).
It also includes the ability to search for variable
objects using the tables from the Hubble Catalog
of Variables project (HCV, https://archive.stsci.
edu/hlsp/hcv).
There are Python Jupyter notebooks available
that demonstrate basic HSC searches, searches
starting from the HCV variable candidates, and
searches of the HSC v3.1 proper motion tables for
the SWEEPS field (which are not included in the
UI but are available through the API). See the HSC
home page for links to these notebooks, which are
designed to put you on the fast track to science
Variable candidates near dwarf galaxy IC 1613 in a color-magnitude diagram, generated
with the HSC (https://archive.stsci.edu/hst/
by querying the HCV using the catalogs API. Many of the variables are in the Cepheid
hsc/#forms).
instability strip.
Future plans
The MAST catalog interfaces are built on a scalable computing fabric that is designed to be robust under the highly variable load that we encounter
from our user community. While we are still tuning our server infrastructure, the current system has demonstrated that it is more resilient during
periods with high query rates (e.g., at the time of the PS1 DR2 release). The new architecture is also beneficial to other MAST users because it
isolates the loads from catalog services so that they do not impact other MAST services.
MAST is planning to incorporate many other catalogs in our holdings into this new interface. Watch for future releases that include the Guide Star
Catalog, GALEX catalog, TESS and Kepler Input Catalogs (TIC and KIC) and others. We also plan to incorporate more catalogs APIs into the astroquery.
mast module to make it even simpler to use from Python.facebook.com/MASTArchive
HUBBLE SOURCE CATALOG @MAST_News
https://archive.stsci.edu/hst/hsc/
Winter 2021
The Hubble Source Catalog (HSC) is designed to optimize science from the Hubble Space Telescope
by combining the tens of thousands of visit-based source lists in the Hubble Legacy Archive (hla.stsci.
edu) into a single master catalog.
HSC v3 catalog
The HSC v3 catalog (released July 5, 2018) was constructed using the WFPC2, ACS/WFC, WFC3/UVIS and
WFC3/IR Source Extractor source lists from HLA version Data Release 10. The cross-matching process
involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between
closely aligned sources in different images. After correction, the astrometric residuals of cross-matched
sources are significantly reduced, to typically less than 10 mas. The relative astrometry is supported by
using Gaia DR1 as the astrometric backbone for initial corrections, with 2MASS, Pan-STARRS, and SDSS
being used in fields that have too few Gaia objects. In addition, the catalog includes source nondetections. The cross-matching algorithms and the
properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012).
Highlights of recent Hubble Source catalog releases
• HSCv3 includes more than 540 million measurements of 108 million objects. It has improved photometric quality due both to the alignment
algorithm used to match exposures and to improved algorithms for Source Extractor photometry (particularly near the edges of images). See
https://archive.stsci.edu/hst/hsc/help/HSC_faq.html#photometry for details.
• HSCv3.1 (released June 26, 2019) provides proper motions for more than 400,000 objects in the augmented Sagittarius Window Eclipsing
Extrasolar Planet Search (SWEEPS) HST field. This field is within a few degrees of the Galactic center, and most of the stars belong to the
Galactic bulge. Proper motions with a median accuracy of 0.3 milliarcsec/year are provided for stars as faint as magnitude 27. Note that this
accurate astrometric catalog is far deeper than the Gaia catalog, enabling many interesting science projects. It is likely the largest publicly
available set of proper motions that extends to such faint objects.
• The Hubble Catalog of Variables (HCV, released September 24, 2019) is a new High-Level Science Product created from HSCv3 in a
4 year ESA-funded project at the National Observatory of Athens (PI: Alceste Bonanos). The HCV is the first homogeneous catalog of variable
sources found in the HSC. It includes variable stars in our Galaxy and nearby galaxies, as well as transients and variable active galactic nuclei.
The HCV contains 84,428 candidate variable sources (out of 3.7 million HSC sources that were searched for variability) with Vfacebook.com/MASTArchive
HUBBLE SOURCE CATALOG @MAST_News
https://archive.stsci.edu/hst/hsc/
Winter 2021
Use Cases
We have several Use Cases available to help understand the HSC and it’s interfaces. Please go to archive.stsci.edu/hst/hsc/help/HSC_faq.
html#use_case to see them all.
Using the Discovery Portal to perform cross-matching between an input
catalog and the HSC - Search for the Supernova 2005cs progentior in
the galaxy M51
Using CASJOBS to Query the HSC - Globular Clusters in M87 and a
Color Magnitude Diagram for the SMC
Using the Discovery Portal to search for Variable Objects in the HSC - Time Using the Discovery Portal and CasJobs to search for Outlier Objects
Variability in the dwarf irregular galaxy IC 1613 in the HSC - White dwarfs in the Globular Cluster M4
Color-magnitude diagram for more than 700,000 stars in the Small Magel- Light curve for a nova in galaxy M87 selected from the Hubble Catalog
lanic Cloud created by a simple Python notebook using the HSC catalogs of Variables using the HSC catalogs API (https://archive.stsci.edu/
API (https://archive.stsci.edu/hst/hsc/help/api/hscv3_smc_api.html) hst/hsc/help/HCV/HCV_API_demo.html)facebook.com/MASTArchive
PAN-STARRS1 DR2 @MAST_News
ARCHIVE
Winter 2021
Pan-STARRS1 survey Science Examples
The University of Hawaii developed and continues to operate the • Near-Earth and slower moving trans-Neptunian objects, discovered
Panoramic Survey Telescope and Rapid Response System. Pan-STARRS due to optimized survey cadence.
has completed an initial 4-year survey (PS1) with a single 1.8-m tele-
scope atop Haleakala. A 1.4-gigapixel camera with a 7 square-degree • Low-mass stellar and sub-stellar objects, using deep z and y band
field of view imaged the sky north of declination -30 half a dozen times observations with 6-month cadence to measure parallax and proper
motion.
in five bands (g, r, i, z, y). The powerful combination of broad sky cover-
age (30,000 deg2), precise astrometry and photometry, better depth • High redshift quasars, revealed as drop-outs in deep i, z, and y
than SDSS, and multiple epochs will impact every area of astronomy in band photometry. PS1 has discovered 29 QSOs at z > 5.6.
the coming decade. In addition to this 3pi survey, PS1 also imaged 10
• Transients detected by repeated sampling. PS1 discovered tidal
medium-deep fields nightly and performed a deep survey of the nearby disruption events and hundreds of SNe of all kind.
Andromeda Galaxy.
• Microlensing and variable stars in the Andromeda galaxy
Data Products
• 3D extinction maps of the Milky Way, based on fits of PS1 photom-
The PS1 DR2 products (released January 28, 2019) include catalogs etry for a billion stars.
and images with light curves for 2 billion objects. The image collection
contains both the single-epoch “warp” exposures and deep, co-added
stack images made by combining those exposures. The images are
accessible via a fast cutout server (returning FITS images or JPEG
previews) or for download as 0.4 x 0.4 degree FITS skycells. The cata-
logs include grizy measurements from the stack images as well as mean
values of the point-source and extended-source photometry from the
warp images. They also include photometry and astrometry for typically
~50 individual epochs for each object, as well as forced photometry for
objects detected in the stack images.
grz color image of
Sky coverage North of declination -30 degrees
the 3pi survey, which
3pi stack 5σ depth grizy < 23.3, 23.2, 23.1, 22.3, 21.3 covers the whole sky
north of declination
Single epoch 5σ depth grizy < 22.0, 21.8, 21.5, 20.9, 19.7
-30 deg.
PS1 telescope at sunset.
UV and optical lightcurve of PS1-10jh, a
flare due to tidal disruption of a stripped
stellar core (Gezari et al. 2012). GALEX
and PS1 data are fitted with a numeri-
cal model for the mass accretion rate
of tidally disrupted star. 3D dust map of the galaxy, determined by measuring the distance and
extinction toward a billion stars in the PS1 survey (Schlafly et al. 2014,
Green et al. 2014).
The PS1 3pi survey is now a power-
ful discoverer of high redshift QSOs.
The left panel shows the i-band
dropout technique employed, which
is being extended to the z filter to
push beyond z > 6.facebook.com/MASTArchive
PAN-STARRS1 DR2 @MAST_News
ARCHIVE
Winter 2021
Public Archive PS1 Archive Homepage:
https://panstarrs.stsci.edu/
The Space Telescope Science Institute (STScI) released PS1 DR2 on Jan 28, 2019. The
Pan-STARRS catalog is accessible via SQL database queries using the MAST CasJobs PS1 Object Catalog Search:
interface and a VO TAP interface. A new form interface (with an underlying API) enables https://catalogs.mast.stsci.edu/panstarrs/
fast, flexible searches of multiple tables from both the PS1 DR1 and DR2 catalog databases. PS1 Image Cutout Server:
The primary access to the PS1 images is through the PS1 Image Cutout Service. Both the https://ps1images.stsci.edu
catalog and image interfaces can be easily used from scripts. PS1 Casjobs SQL Queries:
https://mastweb.stsci.edu/ps1casjobs
Color PS1 image of the Tadpole Galaxy created with the MAST PS1
image interface using the z/r/g filters https://ps1images.stsci.edu
New web search for the PS1 catalog,
https://catalogs.mast.stsci.edu/panstarrs/
Typical PS1 i-band image in the MAST/HLA interactive image dis-
play. The PS1 catalog sources in the vicinity can be overlaid. Clicking
MAST CasJobs interface allowing direct queries of the PS1 catalog on a source brings up a popup window with the source properties.
https://mastweb.stsci.edu/ps1casjobsTHE HUBBLE LEGACY facebook.com/MASTArchive
@MAST_News
ARCHIVE
hla.stsci.edu
Winter 2021
The Hubble Legacy Archive (HLA)
HLA is designed to facilitate access to science-ready Hubble Space Telescope data by providing enhanced data
products and advanced search and browsing capabilities. The HLA is a joint project of STScI, the Canadian
Astronomy Data Centre (CADC) and, until December 2010, the European Coordinating Facility (ST-ECF).
Current HLA Data Release
HLA DR10.1 was released July 5, 2018. It includes all WFPC2, ACS and WFC3 images that were public as of
October 1, 2017. The visit-level ACS and WFC3 images were reprocessed using a new pipeline that includes
robust exposure and filter alignment algorithms, resulting in improved astrometry and photometry in the HLA
source lists. The DR10 source lists were combined to generate version 3 of the Hubble Source Catalog (HSC).
This HLA release also includes deep, wide-field ACS and WFC3 multi-visit mosaic data products for 1348 fields.
The mosaic pipeline is based on the processing used for the Hubble Frontier Fields images. These images are
astrometrically corrected and aligned using HSC version 2. ACS and WFC3 products are drizzled onto a common
pixel grid, which makes them easy to use.
The HLA interface
The HLA user interface (https://hla.stsci.edu/hlaview.html) provides access to all HLA products and services.
It includes a simple search interface, image previews (including color images), and a footprint view of the sky
coverage. The HLA tools include an interactive image display that provides high-quality previews of the data
at their full resolution, with adjustable contrast, and a spectral viewer that displays one-dimensional data with
the ability to carry out simple analysis. The MAST Portal (https://mast.stsci.edu) also provides access to the
HLA image products with similar tools.
Images, source lists, and other products
The HLA offers combined images for WFC3, ACS, WFPC2 and NICMOS that increase the depth and improve
the quality of the single-exposure data. The combined images have been generated using specialized pipelines
based on AstroDrizzle. The WFPC2 images were generated by CADC.
The HLA also offers source lists for WFC3, ACS and WFPC2 obtained with standard astronomical software.
These source lists can be viewed or retrieved via the standard HLA interface; source positions can also be
overplotted onto the corresponding image directly within the browser. (Sources from several standard catalogs,
including Gaia, Pan-STARRS1, and many others, can also be displayed in the same screen.) These source lists
are cross-matched and integrated into a science-ready database by the HSC project.
The HLA also includes more than 50,000 extracted grism spectra, obtained by the ST-ECF group for ACS and
NICMOS grism data, and more than 11,000 images and spectra from High-Level Science Products (HLSP).
For more information on these and other HLA products, see the HLA release notes at https://hla.stsci.edu/
hla_release.html.
Future plans for the HLA
STScI has developed a new data processing pipeline for the Hubble Advanced Products (HAP), which are
designed to be very similar to the HLA ACS and WFC3 data products. HAP images and source lists for
single visit products are now being generated and distributed along with the standard HST calibrated data
products. These products are available to users immediately (including observations that are still proprietary)
through the MAST Portal. Later in 2021 we will release HAP mosaic products, which combine data from
multiple visits and multiple proposals to produce deep and wide-field images. Once the MAST Portal is
a complete replacement for the HLA interface’s capabilities, we plan to retire the current HLA interface.
As the HLA data products are replaced by HAP, the final HLA versions will be archived as static products.You can also read
