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MDWARFASC - Bright M Dwarf All-Sky Catalog

HEASARC
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Overview

This table contains an all-sky catalog of M dwarf stars with apparent infrared magnitude J < 10. The 8889 stars are selected from the ongoing SUPERBLINK survey of stars with proper motion mu > 40 mas yr-1, supplemented on the bright end with the Tycho-2 catalog. Completeness tests which account for kinematic (proper motion) bias suggest that this catalog represents ~75% of the estimated ~11,900 M dwarfs with J < 10 expected to populate the entire sky. The catalog is, however, significantly more complete for the northern sky (~90%) than it is for the south (~60%). Stars are identified as cool, red M dwarfs from a combination of optical and infrared color cuts, and are distinguished from background M giants and highly reddened stars using either existing parallax measurements or, if such measurements are lacking, using their location in an optical-to-infrared reduced proper motion diagram. These bright M dwarfs are all prime targets for exoplanet surveys using the Doppler radial velocity or transit methods; the combination of low-mass and bright apparent magnitude should make possible the detection of Earth-size planets on short-period orbits using currently available techniques.

Parallax measurements, when available, and photometric distance estimates are provided for all stars, and these place most systems within 60 pc of the Sun. Spectral type estimated from V-J color shows that most of the stars range from K7 to M4, with only a few late M dwarfs, all within 20 pc. Proximity to the Sun also makes these stars good targets for high-resolution exoplanet imaging searches, especially if younger objects can be identified on the basis of X-ray or UV excess. For that purpose, we include X-ray flux from ROSAT and FUV/NUV ultraviolet magnitudes from GALEX for all stars for which a counterpart can be identified in those catalogs. Additional photometric data include optical magnitudes from Digitized Sky Survey plates and infrared magnitudes from the Two Micron All Sky Survey.


Catalog Bibcode

2011AJ....142..138L

References

An All-Sky catalog of Bright M Dwarfs
   Lepine, S., Gaidos, E.
  <Astronomical J., 142, 138 (2011)>
  =2011AJ....142..138L (SIMBAD/NED BibCode)

Provenance

This table was first created by the HEASARC in October 2011 based on electronic versions of Tables 1 and 2 from the reference paper which were obtained from the AJ web site. A slightly revised version based on corrected versions of the input tables received from the author was ingested in December 2011.

Parameters

Name
The name of the star. Each of the 8889 stars in this catalog is identified with the standard proper motion star ID used in the SUPERBLINK proper motion survey, modified by the HEASARC to conform with the naming conventions discussed in the Dictionary of Nomenclature of Celestial Objects. These SUPERBLINK names have prefixes of the form "PMI J" (in the original reference table the prefixes "PM I" were used) followed by five digits which relate to the International Celestial Reference System (ICRS) right ascension (RA) of the star in sexagesimal coordinates; the first four digits are the hours and minutes of RA, the fifth digit is the seconds of RA divided by 6 and rounded down to the nearest integer. These are followed by the declination sign and then four digits which replicate the ICRS Declination (hours, then minutes) of the source. A disambiguation letter (NSEW) is used when the scheme would leave two stars with the same name, with the letter indicating the relative orientation of the stars in the pair.

HIP_Name
The source designation of the star in the Hipparcos Catalog. These aliases are provided for convenience because Hipparcos names are now commonly used to refer to very bright stars, and because many exoplanet surveys have adopted the Hipparcos names in designating the host stars and their exoplanets. The list includes a total of 977 Hipparcos stars.

Tyc_Name
The source designation of the star in the Tycho-2 Catalog. The Tycho-2 names are useful in identifying objects for which the proper motion is known to higher accuracy. The list includes a total of 1859 Tycho-2 stars.

CNS3_Name
The source designation of the stars in the Third Catalog of Nearby Stars, otherwise known as CNS3. These are convenient because CNS3 names have been widely adopted by the exoplanet community to designate nearby stars. The CNS3 counterparts are found after cross-correlation with the catalog of revised positions by Stauffer et al. (2010, PASP, 122, 885: available in HEASARC Browse as the GLIESE2MAS table) which lists 4106 objects. A total of 1529 stars from the present catalog of bright M dwarfs are thus matched to their CNS3 counterparts. Stars with CNS3 counterparts include most of the very nearest systems. However, the CNS3 does suffer from a significant kinematic bias because it is largely based on the proper motion catalogs of Luyten, particularly the LHS catalog which has a relatively high proper motion limit mu >~ 450 mas yr-1. As a result, many stars in the present list which are identify herein as very nearby objects do not have CNS3 names; these are typically stars with relatively small (mu <~ 300 mas yr-1) proper motions.

RA
The Right Ascension of the star in the selected equinox. This was given in decimal degree coordinates (2000.0 epoch) in the ICRS system and to a precision of 10-6 degrees in the original table. The 2000.0 epoch means that current positions must be extrapolated using the tabulated proper motions. For stars listed in the Hipparcos catalog, the authors have extrapolated the positions to the 2000.0 epoch from the values listed in van Leeuwen (2007, A&A, 474, 653: available in HEASARC Browse as the HIPNEWCAT table) which were listed for epoch 1991.25. For all other stars, the 2000.0 coordinates are based on the position of their 2MASS counterparts as listed in Cutri et al. (2003, The 2MASS All-Sky Catalog of Point Sources) and extrapolated to the 2000.0 epoch from the epoch of the 2MASS observations. The positions are typically accurate to 0.8 arcsecs, which are the quoted 2MASS catalog errors on the absolute astrometry; proper motion errors have little effect on the accuracy of the extrapolated positions because of the proximity of the 2MASS survey epoch to the millennium year (<3 years).

Dec
The Declination of the star in the selected equinox. This was given in decimal degree coordinates (2000.0 epoch) in the ICRS system and to a precision of 10-6 degrees in the original table. The 2000.0 epoch means that current positions must be extrapolated using the tabulated proper motions. For stars listed in the Hipparcos catalog, the authors have extrapolated the positions to the 2000.0 epoch from the values listed in van Leeuwen (2007, A&A, 474, 653: available in HEASARC Browse as the HIPNEWCAT table) which were listed for epoch 1991.25. For all other stars, the 2000.0 coordinates are based on the position of their 2MASS counterparts as listed in Cutri et al. (2003, The 2MASS All-Sky Catalog of Point Sources) and extrapolated to the 2000.0 epoch from the epoch of the 2MASS observations. The positions are typically accurate to 0.8 arcsecs, which are the quoted 2MASS catalog errors on the absolute astrometry; proper motion errors have little effect on the accuracy of the extrapolated positions because of the proximity of the 2MASS survey epoch to the millennium year (<3 years).

LII
The Galactic Longitude of the star.

BII
The Galactic Latitude of the star.

PM_Tot
The total annual proper motion of the star, in arcsecs/yr. These proper motions are from three separate sources. Stars with Hipparcos counterparts are listed with their proper motion from the Hipparcos catalog (van Leeuwen 2007). Stars not in the Hipparcos catalog but with counterparts in the Tycho-2 catalog are listed with their proper motion from Tycho-2 (Hog et al. 2000, A&A, 355, L27). The Hipparcos and Tycho-2 proper motions are typically accurate to 0.5-2.0 mas yr-1. For stars not listed in either Hipparcos or Tycho-2, the proper motions listed are those measured in the SUPERBLINK proper motion survey. These proper motions are based on a re-analysis of the DSS images, as described in detail in Lepine & Shara (2005, AJ, 129, 1483); these proper motions have a typical precision of +/- 8 mas yr-1. One can determine the source of the proper motion by checking whether the star has a Hipparcos or Tycho-2 name.

PM_RA
The vector component of the annual proper motion of the star in the Right Ascension direction, in arcsecs/yr.

PM_Dec
The vector component of the annual proper motion of the star in the Declination direction, in arcsecs/yr.

Parallax
The astrometric (trigonometric) parallax of the star, in arcseconds. Astrometric parallaxes are recovered from the literature for 1422 of the M dwarfs in this catalog.

Parallax_Error
The measurement error in the quoted trigonometric parallax, in arcseconds.

Ref_Parallax
The reference source for the trigonometric parallax coded as follows (see Section 2.4.1 of the reference paper for a discussion of the list of papers and catalogs that were searched to recover the parallaxes):

      Co05: Costa et al. 2005, AJ, 130, 337;
      Ga08: Gatewood 2008, AJ, 136, 452;
      Ga09: Gatewood & Coban 2009, AJ, 137, 402;
      Ha93: Harrington et al. 1993, AJ, 105, 1571;
      He06: Henry et al. 2006, AJ, 132, 2360;
      Ja05: Jao et al. 2005, AJ, 129, 1954;
      Ja11: Jao et al. 2011, AJ, 141, 117;
      Kh10: Khrutskaya et al. 2010, Astron. Lett, 35, 576;
      Le09: Lepine et al. 2009, AJ, 137, 4109;
      Mo92: Monet et al. 1992, AJ, 103, 638;
      My02: Myers et al. 2002, SKY2000 Master Catalog, Version 4;
      Ri10: Riedel et al. 2010, AJ, 140, 897;
      Sm07: Smart et al. 2007, A&A, 464, 787;
      VA95: van Altena et al. 1995, General Catalog of Trigonometric
              Stellaar Parallaxes;
      VL07: van Leeuwen 2007, A&A, 474, 653;
      NSTA: NStars database (http://nstars.nau.edu/nau_nstars/index.htm).
  

RASS_Count_Rate
The ROSAT All-Sky Survey (RASS) count rate of the associated X-ray source, in ct/s. The authors cross-correlated this list of bright M dwarfs with both the ROSAT All-Sky Bright Source Catalog (Voges et al. 1999, A&A, 349, 389: available in HEASARC Browse as the RASSBSC table) and the ROSAT All-Sky Survey Faint Source Catalog (Voges et al. 2000, IAU Circ. 7432, 1: available in HEASARC Browse as the RASSFSC table). They used a search radius of 15 arcsecs, which is on the order of the astrometric precision of the ROSAT catalog. This search identified 1065 stars with X-ray counterparts.

GALEX_Fmag
The GALEX far-UV (1350-1750 Angstroms) magnitude of the star. The catalog was cross-correlated against the fifth data release (DR5) of the GALEX mission. Using a 5 arcsecs search radius, the authors found GALEX counterparts for 3905 of the 8889 stars on their list. Some 762 objects have counterparts in both the FUV and NUV, while 3115 have counterparts only in the NUV, leaving 28 stars with a counterpart in the FUV only.

GALEX_Nmag
The GALEX near-UV (1750-2800 Angstroms) magnitude of the star. The catalog was cross-correlated against the fifth data release (DR5) of the GALEX mission. Using a 5 arcsecs search radius, the authors found GALEX counterparts for 3905 of the 8889 stars on their list. Some 762 objects have counterparts in both the FUV and NUV, while 3115 have counterparts only in the NUV, leaving 28 stars with a counterpart in the FUV only.

BT_Mag
The Tycho-2 BT magnitude of the star. The authors included optical magnitudes BT and VT as they are listed in the Hipparcos and Tycho-2 catalogs, when these were available. The BT and VT magnitudes are useful because they are generally more accurate (0.1 mag or better) than the photographic magnitudes which are listed for all the stars

VT_Mag
The Tycho-2 VT magnitude of the star. The authors included optical magnitudes BT and VT as they are listed in the Hipparcos and Tycho-2 catalogs, when these were available. The BT and VT magnitudes are useful because they are generally more accurate (0.1 mag or better) than the photographic magnitudes which are listed for all the stars

BJ_Mag
The USNO-B1.0 photographic blue (IIIaJ) magnitude b of the star. Optical magnitudes are obtained from the USNO-B1.0 catalog of Monet et al. (2003, AJ, 125, 984), which is based on scans of historical photographic surveys. The blue magnitudes are extracted mostly from scans of IIIaJ plates from the Palomar Sky Surveys (POSS-I, POSS-II) and the Southern ESO Schmidt (SERC) Survey. Red magnitudes are extracted from scans of IIIaF plates from POSS-I and POSS-II and also from the Anglo-Australian Observatory red survey (AAO-red). Photographic infrared magnitudes are extracted from IVn plates from POSS-II and SERC. Cross-correlation with the USNO-B1.0 catalog is performed as part of the SUPERBLINK quality control procedure, and all ambiguous cases are verified by visual examination using overlays of the USNO-B1.0 sources on the DSS scans. Since the optical b, r, i, magnitudes are based on scans of photographic plates, they are generally not as reliable as magnitudes measured on electronic detectors, such as those from 2MASS and GALEX. Photographic magnitudes are typically accurate to only +/- 0.5 mag.

RF_Mag
The USNO-B1.0 photographic red (IIIaF) magnitude r of the star. Optical magnitudes are obtained from the USNO-B1.0 catalog of Monet et al. (2003, AJ, 125, 984), which is based on scans of historical photographic surveys. The blue magnitudes are extracted mostly from scans of IIIaJ plates from the Palomar Sky Surveys (POSS-I, POSS-II) and the Southern ESO Schmidt (SERC) Survey. Red magnitudes are extracted from scans of IIIaF plates from POSS-I and POSS-II and also from the Anglo-Australian Observatory red survey (AAO-red). Photographic infrared magnitudes are extracted from IVn plates from POSS-II and SERC. Cross-correlation with the USNO-B1.0 catalog is performed as part of the SUPERBLINK quality control procedure, and all ambiguous cases are verified by visual examination using overlays of the USNO-B1.0 sources on the DSS scans. Since the optical b, r, i, magnitudes are based on scans of photographic plates, they are generally not as reliable as magnitudes measured on electronic detectors, such as those from 2MASS and GALEX. Photographic magnitudes are typically accurate to only +/- 0.5 mag.

In_Mag
The USNO-B1.0 photographic infrared (IVn) magnitude i of the star. Optical magnitudes are obtained from the USNO-B1.0 catalog of Monet et al. (2003, AJ, 125, 984), which is based on scans of historical photographic surveys. The blue magnitudes are extracted mostly from scans of IIIaJ plates from the Palomar Sky Surveys (POSS-I, POSS-II) and the Southern ESO Schmidt (SERC) Survey. Red magnitudes are extracted from scans of IIIaF plates from POSS-I and POSS-II and also from the Anglo-Australian Observatory red survey (AAO-red). Photographic infrared magnitudes are extracted from IVn plates from POSS-II and SERC. Cross-correlation with the USNO-B1.0 catalog is performed as part of the SUPERBLINK quality control procedure, and all ambiguous cases are verified by visual examination using overlays of the USNO-B1.0 sources on the DSS scans. Since the optical b, r, i, magnitudes are based on scans of photographic plates, they are generally not as reliable as magnitudes measured on electronic detectors, such as those from 2MASS and GALEX. Photographic magnitudes are typically accurate to only +/- 0.5 mag.

Jmag
The 2MASS infrared J magnitude of the star. As part of the quality control process, all the stars in the SUPERBLINK proper motion survey have their counterparts identified in the 2MASS catalog of Cutri et al. (2003, The 2MASS All-Sky Catalog of Point Sources). As described in Section 3.2.1 of the reference paper, the 2MASS counterparts provide the absolute astrometry for SUPERBLINK objects. Because of the color restriction V-J > 2.7 given in equation (1) of the reference, every object in the catalog is required to have a counterpart in 2MASS. The magnitudes are generally accurate to +/- 0.08 mag, though one should refer to the 2MASS documentation for a detailed discussion of magnitude errors and uncertainties. Very bright stars (J < 5), in particular, are saturated in 2MASS and have larger photometric uncertainties.

Hmag
The 2MASS infrared H magnitude of the star. As part of the quality control process, all the stars in the SUPERBLINK proper motion survey have their counterparts identified in the 2MASS catalog of Cutri et al. (2003, The 2MASS All-Sky Catalog of Point Sources). As described in Section 3.2.1 of the reference paper, the 2MASS counterparts provide the absolute astrometry for SUPERBLINK objects. Because of the color restriction V-J > 2.7 given in equation (1) of the reference, every object in the catalog is required to have a counterpart in 2MASS. The magnitudes are generally accurate to +/- 0.08 mag, though one should refer to the 2MASS documentation for a detailed discussion of magnitude errors and uncertainties. Very bright stars (J < 5), in particular, are saturated in 2MASS and have larger photometric uncertainties.

Ks_Mag
The 2MASS infrared Ks magnitude of the star. As part of the quality control process, all the stars in the SUPERBLINK proper motion survey have their counterparts identified in the 2MASS catalog of Cutri et al. (2003, The 2MASS All-Sky Catalog of Point Sources). As described in Section 3.2.1 of the reference paper, the 2MASS counterparts provide the absolute astrometry for SUPERBLINK objects. Because of the color restriction V-J > 2.7 given in equation (1) of the reference, every object in the catalog is required to have a counterpart in 2MASS. The magnitudes are generally accurate to +/- 0.08 mag, though one should refer to the 2MASS documentation for a detailed discussion of magnitude errors and uncertainties. Very bright stars (J < 5), in particular, are saturated in 2MASS and have larger photometric uncertainties.

Vmag_Eff
The estimated visual magnitude of the star. For bright stars, this is the visual magnitude VT quoted in the Hipparcos or Tycho-2 catalogs. For faint stars, it is a combination of the photographic b, r, and i magnitudes, following the algorithm described in Lepine & Shara (2005, AJ, 129, 1483) where this effective visual magnitude is labeled as Ve. In this present study, the authors use the shorter form V for convenience, but it should be understood that all the mentions of V actually refer to this effective visual magnitude Ve.

VJ_Color
The optical-to-infrared V-J color of the star

Phot_Parallax
The photometric parallax of the star, in arcseconds. Photometric distances are estimated for all the stars based on the (V-J)-MV color-magnitude relationship for M dwarfs calibrated in Lepine (2005, AJ, 130, 1247) and detailed in equation (14) of the reference paper. Photometric parallaxes piphot are then calculated based on the estimated absolute magnitude MV and the apparent visual magnitude V. As discussed in Lepine (2005), the relationship has a scatter of 0.7 mag about the mean, which typically results in photometric distances with errors of +/- 50%. In Figure 9 of the reference paper, teh authors compare the photometric distances to triangulated distances, for stars with available parallaxes. Of the 1422 M dwarfs with parallaxes, some 1206 stars have photometric distance estimates within +/- 50% of the astrometric distance, but only 772 have photometric distances that are accurate to +/- 20%. There is also a significant number of outliers which could be unrecognized giants, young field stars, or unresolved doubles, all of which would have distances underestimated by photometry. Metal-poor stars (M subdwarfs) on the other hand would have their distances overestimated by photometry. Spectroscopic follow-up would be required to identify all such objects. Thus, while photometric distances are conveniently provided here for all the stars, one should bear in mind that these are mainly for guidance purposes, as these distances carry large uncertainties in many cases. Astrometric parallaxes should be preferred for stars for which they are available, and should be measured for the remaining objects in this catalog.

Phot_Parallax_Error
The uncertainty in the photometric parallax of the star, in arcseconds.

Phot_Spect_Type
The photometric spectral subtype ST of the star. For all the stars, the authors provide an estimated spectral subtype which is based on the relationship between V-J color and the spectral subtype (see Figure 3 of the reference paper). They use a simple two-component linear relationship to estimate the subtype ST which is given in equation (15) of the reference paper. The authors use lowercase letters (k,m) instead of the usual uppercase (K, M) to indicate that the spectral type is only an estimate; a value of ST = = -1 yields an estimated subtype of k7. A histogram of the estimated subtype distribution is shown in Figure 10 of the reference paper, where it becomes clear that this magnitude-limited catalog of bright M dwarfs is biased toward stars of earlier subtypes, and breaks down beyond spectral subtype M4. These subtypes may be used as a guide in selecting targets of interest. Some of the stars on the list, in particular stars listed in the CNS3, already have published literature about them, and the interested user would be advised to verify the existence of formal spectral classification(s). The authors are currently conducting a spectroscopic follow-up survey to obtain formal spectral types for the brightest stars in this catalog, and intend to provide formal spectral classifications for them in the near future.

Class
The HEASARC Browse object classification, based on the value of the phot_spect_type parameter (q.v. for the caveats on the accuracy of this spectral classification).


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Page Author: Browse Software Development Team
Last Modified: 5-Dec-2011