This table contains a spectroscopic catalog of the 1564 brightest (J < 9^m) M-dwarf candidates in the northern sky, as selected from the SUPERBLINK proper-motion catalog (Lepine and Shara 2005, AJ, 129, 1483). Observations confirm 1408 of the candidates to be late-K and M dwarfs with spectral subtypes K7 - M6. From the low (mu > 40 mas yr^-1) proper motion limit and high level of completeness of the SUPERBLINK catalog in that magnitude range, the authors estimate that their spectroscopic census most likely includes > 90% of all existing, northern-sky M dwarfs with apparent magnitude J < 9^m. Only 682 stars in this sample are listed in the Third Catalog of Nearby Stars (CNS3, Gliese and Jahreiss 1991); most others are relative unknowns and have spectroscopic data presented here for the first time. Spectral subtypes are assigned based on spectral index measurements of CaH and TiO molecular bands; a comparison of spectra from the same stars obtained at different observatories, however, reveals that spectral band index measurements are dependent on spectral resolution, spectrophotometric calibration, and other instrumental factors. As a result, the authors find that a consistent classification scheme requires that spectral indices be calibrated and corrected for each observatory/instrument used. After systematic corrections and a recalibration of the subtype-index relationships for the CaH2, CaH3, TiO5, and TiO6 spectral indices, the authors find that they can consistently and reliably classify all the stars to a half-subtype precision. The use of corrected spectral indices further requires them to recalibrate the zeta parameter, a metallicity indicator based on the ratio of TiO and CaH optical bandheads. However, the authors find that their zeta values are not sensitive enough to diagnose metallicity variations in dwarfs of subtypes M2 and earlier (+/- 0.5 dex accuracy) and are only marginally useful at later M3-M5 subtypes (+/- 0.2 dex accuracy). Fits of their spectra to the Phoenix atmospheric model grid are used to estimate effective temperatures. These suggest the existence of a plateau in the M1-M3 subtype range, in agreement with model fits of infrared spectra but at odds with photometric determinations of T_eff. Existing geometric parallax measurements are extracted from the literature for 624 stars, and are used to determine spectroscopic and photometric distances for all the other stars. Active dwarfs are identified from measurements of H-alpha equivalent widths, and the authors find a strong correlation between H-alpha emission in M dwarfs and detected X-ray emission from ROSAT and/or a large UV excess in the GALEX point source catalog. Proper motion data and photometric distances are combined in order to evaluate the (U, V, W) distribution in velocity space, which is found to correlate tightly with the velocity distribution of G dwarfs in the solar neighborhood. However, active stars show a smaller dispersion in their space velocities, which is consistent with those stars being younger on average. The authors state that this catalog will be very useful for guiding the selection of the best M dwarf targets for exoplanet searches, in particular those using high-precision radial velocity measurements. This online catalog was created by the HEASARC in June 2013 based on a machine-readable version of Tables 1, 3 and 7 from the paper which were obtained from the AJ website (Tables 1 and 3) or from the first author (Table 7). This is a service provided by NASA HEASARC .

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. 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. This is a service provided by NASA HEASARC .

The BSC5P database table contains data derived from the Bright Star Catalog, 5th Edition, preliminary, which is widely used as a source of basic astronomical and astrophysical data for stars brighter than magnitude 6.5. The database contains the identifications of included stars in several other widely-used catalogs, double- and multiple-star identifications, indication of variability and variable-star identifiers, equatorial positions for B1900.0 and J2000.0, galactic coordinates, UBVRI photoelectric photometric data when they exist, spectral types on the Morgan-Keenan (MK) classification system, proper motions (J2000.0), parallax, radial- and rotational-velocity data, and multiple-star information (number of components, separation, and magnitude differences) for known non-single stars. This table was created by the HEASARC in 1995 based upon a file obtained from either the ADC or the CDS. A number of revisions have been made by the HEASARC to this original version, e.g., celestial positions were added for the 14 non-stellar objects which have received HR numbers: HR 92, 95, 182, 1057, 1841, 2472, 2496, 3515, 3671, 6309, 6515, 7189, 7539 and 8296. In January 2014, the very incorrect position for HR 3671 = NGC 2808 was fixed (the Declination is -65 degrees not +65 degrees!), and smaller corrections were made to the positions of HR 2496, 3515 and 6515 so as to bring them in better agreement with the positions listed in SIMBAD and NED This is a service provided by NASA HEASARC .

The young stellar cluster illuminating the W40 H II region, one of the nearest massive star-forming regions (SFRs), has been observed with the ACIS detector on board the Chandra X-ray Observatory. Due to its high obscuration, this is a poorly studied stellar cluster with only a handful of bright stars visible in the optical band, including three OB stars identified as primary excitation sources. The authors detect 225 X-ray sources, of which 85% are confidently identified as young stellar members of the region. Two potential distances of the cluster, 260 pc and 600 pc, are used in the paper. Supposing the X-ray luminosity function of SFRs to be universal, it supports a 600 pc distance as a lower limit for W40 and a total population of at least 600 stars down to 0.1 M_sun under the assumption of a coeval population with a uniform obscuration. In fact, there is strong spatial variation in K_s-band-excess disk fraction and non-uniform obscuration due to a dust lane that is identified in absorption in optical, infrared, and X-ray. The dust lane is likely part of a ring of material which includes the molecular core within W40. In contrast to the likely ongoing star formation in the dust lane, the molecular core is inactive. The star cluster has a spherical morphology, an isothermal sphere density profile, and mass segregation down to 1.5 M_sun. However, other cluster properties, including a <= 1 Myr age estimate and ongoing star formation, indicate that the cluster is not dynamically relaxed. X-ray diffuse emission and a powerful flare from a young stellar object are also reported in the reference paper. This table was created by the HEASARC in March 2011 based on electronic versions of Tables, 1, 2 and 4 of the reference paper which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .

The BESTARS database tables contains a compilation of data concerning stars of type Be. For the purposes of this compilation, a Be star is defined as a non-supergiant B star which showed emission in one Balmer line at least once. Stars without published MK spectral types have been excluded, except for 132 stars from Bidelman and MacConnell (1973), who used the above definition but included no spectral types. There are 1,159 stars included in this list. This is a service provided by NASA HEASARC .

This contains some of the results from the first high spatial resolution X-ray study of the massive star-forming region NGC 6357, which were obtained in a 38 ks Chandra/ACIS observation. Inside the brightest constituent of this large H II region complex is the massive open cluster Pismis 24. It contains two of the brightest and bluest stars known, yet remains poorly studied; only a handful of optically bright stellar members have been identified. The authors have investigated the cluster extent and initial mass function and detected ~800 X-ray sources with a limiting sensitivity of ~ 10³⁰ erg s^-1: this provides the first reliable probe of the rich intermediate-mass and low-mass population of this massive cluster, increasing the number of known members from optical studies by a factor of ~ 50. The high-luminosity end (log L[2-8 keV] >= 30.3 erg s^-1) of the observed X-ray luminosity function in NGC 6357 is clearly consistent with a power-law relation as seen in the Orion Nebula Cluster and Cepheus B, yielding the first estimate of NGC 6357's total cluster population, a few times the known Orion population. The long-standing L_X ~ 10^-7 L_bol correlation for O stars is confirmed. Twenty-four candidate O stars and one possible new obscured massive YSO or Wolf-Rayet star are presented. Many cluster members are estimated to be intermediate-mass stars from available infrared photometry (assuming an age of ~ 1 Myr), but only a few exhibit K-band excess. The authors report the first detection of X-ray emission from an evaporating gaseous globule at the tip of a molecular pillar; this source is likely a B0-B2 protostar. NGC 6357 was observed on 2004 July 9 with the Imaging Array of the Advanced CCD Imaging Spectrometer (ACIS-I) on board Chandra. Four front-illuminated (FI) CCDs form the ACIS-I, which covers a field of view (FOV) of ~ 17 by 17 arcminutes. The observation was made in the standard Timed Exposure, Very Faint mode, with 3.2 s integration time and 5 pixel by 5 pixel event islands. The total exposure time was 38 ks and the satellite roll angle was 289 degrees. The aim point was centered on the O3 If star Pis 24-1, the heart of the OB association Pismis 24. The Chandra observation ID is 4477. Data reduction started with filtering the Level 1 event list processed by the Chandra X-ray Center pipeline to recover an improved Level 2 event list. To improve absolute astrometry, X-ray positions of ACIS-I sources were obtained by running the wavdetect wavelet-based source detection algorithm within the Chandra Interactive Analysis of Observations (CIAO) package on the original Level 2 event list, using only the central 8 by 8 arcminutes of the field. The resulting X-ray sources were matched to the 2MASS point source catalog. The authors calculated the position offsets between 277 X-ray sources and their NIR counterparts and applied an offset of +0.02" in right ascension (R.A.) and -0.33" in declination to the X-ray coordinates. From an initial list of 910 potential X-ray sources, the authors rejected sources with a P_B > 1% likelihood of being a background fluctuation. The trimmed source list includes 779 sources, with full-band (0.5 - 8.0 keV) net (background-subtracted) counts ranging from 1.7 to 1837 counts. The 779 valid sources were purposely divided by the authors into two lists: the 665 sources with P_B < 0.1% make up the primary source list of highly reliable sources (Table 1 in the reference paper; sources with source_type = 'M' in this table), and the remaining 114 sources with P_B >= 0.1% likelihood of being spurious background fluctuations were listed as tentative sources in Table 2 of the reference paper (source_type = 'T' in this table). The authors believe that most of these tentative sources are likely real detections. This table was created by the HEASARC in October 2007 based on the merger of the electronic versions of Tables

This table contains results from a multi-epoch radio study of the Taurus-Auriga complex made with the Karl G. Jansky Very Large Array (JVLA) at frequencies of 4.5 GHz and 7.5 GHz. A total of 610 sources were detected, 59 of which are related to young stellar objects (YSOs) and 18 to field stars. The properties of 56% of the young stars are compatible with non-thermal radio emission. The authors also show that the radio emission of more evolved YSOs tends to be more non-thermal in origin and, in general, that their radio properties are compatible with those found in other star-forming regions. By comparing their results with previously reported X-ray observations, the authors noticed that YSOs in Taurus-Auriga follow a Guedel-Benz relation with a scaling factor, kappa, of 0.03, as they previously suggested for other regions of star formation. In general, YSOs in Taurus-Auriga and in all the previous studied regions seem to follow this relation with a dispersion of ~1 dex. Finally, the authors propose that most of the remaining sources are related with extragalactic objects but provide a list of 46 unidentified radio sources whose radio properties are compatible with a YSO nature (identified in this implementation of their catalog by values for the parameter radio_yso_flag of 'Y'). The observations were obtained with the JVLA of the National Radio Astronomy Observatory (NRAO) in its B and BnA configuration. Two frequency sub-bands, each 1 GHz wide, and centered at 4.5 and 7.5 GHz, respectively, were recorded simultaneously. The observations were obtained in three different time periods (February 25/26/28 to March 6, April 12/17/20/25, and April 30 to May 1/5/14/22, all in 2011) typically separated from one another by a month: see Table 1 of the reference paper for more details. For their study, the authors observed 127 different target fields distributed across the cloud complex (Figure 1 of the reference paper). The fields were chosen to cover previously known YSOs. In 33 of those fields, the authors could observe more than one YSO target, while in the remaining 94 fields, only one YSO was targeted. In most cases, the infrared evolutionary class (i.e., Classes I, II, or III) or T Tauri evolutionary status (classical or weak line) of the targeted sources was known from the literature. The final images covered circular areas of 8.8 and 14.3 arcminutes in diameter, for the 7.5 and 4.5 GHz sub-bands, respectively, and were corrected for the effects of the position-dependent primary beam response. The noise levels reached for each individual observation was about ~40 µJy and ~30 µJy, at 4.5 GHz and7.5 GHz, respectively. The visibilities of the three, or two, observations obtained for each field were concatenated to produce a new image with a lower noise level (of about ~25 µJy at 4.5 GHz and ~18 µJy at 7.5 GHz). The angular resolution of ~1 arcsecond (see the synthesized beam sizes in Table 1 of the reference paper) allows an uncertainty in position of ~0.1 arcseconds or better. In the observed area, there are a total of 196 known YSOs.The first step was the identification of radio sources in the observed fields. The authors follow the procedure and criteria presented by Dzib et al. (2013, ApJ, 775, 63) who consider a detection as firm if the sources have a flux larger than 4 times the noise level and there is a counterpart known at another wavelength, else they require a flux which is 5 times the noise level. The identification was done using the images corresponding to the concatenation of the observed epochs, which provides the highest sensitivity. From this, a total of 609 sources were detected. Of these sources, 215 were only detected in the 4.5 GHz sub-band, while six were only detected in the 7.5 GHz sub-band. The remaining 388 sources were detected in both sub-bands. The authors searched the literature for previous radio detections, and for counterparts at X-ray, optical, near-infrared, and mid-infrared wavelengths. The