MaStar Overview

The observations are obtained mostly by piggybacking on the APOGEE-2 survey during bright time, using MaNGA fiber bundles and the BOSS optical spectrographs. The use of fiber bundles allows us to obtain much more accurate flux calibration than previous SDSS surveys of stars that use single fibers; see the Observing Strategy page for details of our observations.

For detailed information about the instruments, please see the MaNGA Instrument page.

Extinction-corrected color-luminosity diagram for the DR17 version of the MaStar Library, color-coded by metallicity (click to enlarge). The derivation of the absolute magnitudes and extinction-corrected BP-RP colors are based on distances derived by Bailer-Jones et al. (2021) using Gaia EDR3 and the 3D dust map produced by Green et al.(2019).

The DR17 version of the MaStar Library is significantly expanded compared to DR15. We have finished all observations. This release includes all the data. Of all the stars observed, we have selected a subset of stars, termed 'good stars', with good quality visit spectra, termed 'good visits'. Each 'visit' is defined as the observation obtained for a star on a single night. This is the primary product of this release. It includes 59,266 good quality single visit spectra for 24,130 unique good stars. Most stars are assigned a unique MaNGAID. A small number of stars have multiple MaNGAIDs associated with each of them.

The DR17 release includes a summary file called 'mastarall-(version).fits' and a spectra file called 'mastar-goodspec-(version).fits'. The summary file contains a 'GOODSTARS' table, a 'GOODVISITS' table, an 'ALLSTARS' table, and an 'ALLVISITS' table. The 'GOODSTARS' table lists the ID, location, photometry, and input stellar parameters, etc. for all stars with good quality visit spectra. It has one entry per unique MaNGAID. The 'ALLSTARS' table lists these information for all stars targeted regardless of whether it has good quality visit spectra or not.
The 'GOODVISITS' table lists the information needed to locate all good quality visits for each good star, the radial velocity used to shift each spectrum to restframe, and spectral quality information. The 'ALLVISITS' table lists these information for all visits regardless of the quality. The spectra file contains all the good quality single visits spectra, matching the order of entries in the 'GOODVISITS' table. We also provide a spectra file called 'mastar-badspec-(version).fits', which contains all the visit spectra we rejected due to quality issues.

• The MaStar Catalog page provides the details about the summary file -- 'mastarall'.
• The MaStar Spectra page provides the details about the spectra file -- 'mastar-goodspec'.
• The MaStar Data Access page provides information about ways to access the data.
• The MaStar Crossmatch page provides the crossmatched photometry of MaStar stars from Gaia, 2MASS, PanSTARRS-1, and spectral type information collected from Simbad.
• The MaStar Stellar Parameters page provides four catalogs of stellar parameters using different approaches and a median 'best' catalog.
• The MaStar Caveats page lists important usage caveats for the data. You are strongly encouraged to read this.
• The MaStar Tutorial page provides tutorials for using the MaStar data.

In addition, DR17 also contains the raw data from the six years of observations, the intermediate data reduction pipeline (DRP) products, and the combined, flux-calibrated, individual visit and individual exposure spectra.

For more detailed information on the MaStar survey in DR17, see the list of links on this page.