We present a catalogue of non-nuclear regions containing Wolf-Rayet stars in the metal-rich spiral galaxy M 83 (NGC 5236). From a total of 283 candidate regions identified using He II {lambda}4686 imaging with VLT-FORS2, Multi Object Spectroscopy of 198 regions was carried out, confirming 132 WR sources. From this sub-sample, an exceptional content of ~1035+/-300 WR stars is inferred, with N(WC)/N(WN) ~ 1.2, continuing the trend to larger values at higher metallicity amongst Local Group galaxies, and greatly exceeding current evolutionary predictions at high metallicity.
We present a narrow-band Very Large Telescope/Focal Reduced Low-dispersion Spectrograph #1 imaging survey of the SAB(rs)cd spiral galaxy NGC 5068, located at a distance of 5.45Mpc, from which 160 candidate Wolf-Rayet sources have been identified, of which 59 cases possess statistically significant {lambda}4686 excesses. Follow-up Gemini Multi-Object Spectrograph spectroscopy of 64 candidates, representing 40 per cent of the complete photometric catalogue, confirms Wolf-Rayet signatures in 30 instances, corresponding to a 47 per cent success rate. 21 out of 22 statistically significant photometric sources are spectroscopically confirmed.
We present a VLT/FORS1 survey of Wolf-Rayet (WR) stars in the spiral galaxy NGC 1313. In total, 94 WR candidate sources have been identified from narrow-band imaging. Of these, 82 have been spectroscopically observed, for which WR emission features are confirmed in 70 cases, one of which also exhibits strong nebular HeII{lambda}4686 emission. We also detect strong nebular HeII{lambda}4686 emission within two other regions of NGC 1313, one of which is a possible supernova remnant. Nebular properties confirm that NGC 1313 has a metal content log(O/H)+12=8.23+/-0.06, in good agreement with previous studies. From continuum-subtracted H{alpha} images we infer a global star formation rate of 0.6M_{sun}/yr. Using template LMC WR stars, spectroscopy reveals that NGC 1313 hosts a minimum of 84 WR stars. Our census comprises 51 WN stars, including a rare WN/C transition star plus 32 WC stars. In addition, we identify one WO star which represents the first such case identified beyond the Local Group. The bright giant HII region PES 1, comparable in H{alpha} luminosity to NGC 595 in M 33, is found to host a minimum of 17 WR stars. The remaining photometric candidates generally display photometric properties consistent with WN stars, such that we expect a global WR population of ~115 stars with N(WR)/N(O)~0.01 and N(WC)/N(WN)~0.4.
Massive stars, although being important building blocks of galaxies, are still not fully understood. This especially holds true for Wolf-Rayet (WR) stars with their strong mass loss, whose spectral analysis requires adequate model atmospheres. Following our comprehensive studies of the WR stars in the Milky Way, we now present spectroscopic analyses of almost all known WN stars in the LMC. For the quantitative analysis of the wind-dominated emission-line spectra, we employ the Potsdam Wolf-Rayet (PoWR) model atmosphere code. By fitting synthetic spectra to the observed spectral energy distribution and the available spectra (ultraviolet and optical), we obtain the physical properties of 107 stars. We present the fundamental stellar and wind parameters for an almost complete sample of WN stars in the LMC. Among those stars that are putatively single, two different groups can be clearly distinguished. While 12% of our sample are more luminous than 10^6^L_{sun}_ and contain a significant amount of hydrogen, 88% of the WN stars, with little or no hydrogen, populate the luminosity range between log(L/L_{sun}_)=5.3...5.8.
We use archival HARPS spectra to detect three planets orbiting the M3 dwarf Wolf 1061 (GJ 628). We detect a 1.36M_{Earth}_ minimum-mass planet with an orbital period P=4.888days (Wolf 1061b), a 4.25M_{Earth}_ minimum-mass planet with orbital period P=17.867days (Wolf 1061c), and a likely 5.21M_{Earth}_ minimum-mass planet with orbital period P=67.274days (Wolf 1061d). All of the planets are of sufficiently low mass that they may be rocky in nature. The 17.867day planet falls within the habitable zone for Wolf 1061 and the 67.274day planet falls just outside the outer boundary of the habitable zone. There are no signs of activity observed in the bisector spans, cross-correlation FWHMs, calcium H & K indices, NaD indices, or H{alpha} indices near the planetary periods. We use custom methods to generate a cross-correlation template tailored to the star. The resulting velocities do not suffer the strong annual variation observed in the HARPS DRS velocities. This differential technique should deliver better exploitation of the archival HARPS data for the detection of planets at extremely low amplitudes.
This catalog, also called the Finding List (FL) of Interacting Binaries (5th edition), was abstracted from the Card Catalog maintained at the University of Florida which contains information on all published, and to the extent available, unpublished work on eclipsing binaries. The Card Catalog originated with Raymond Smith Dugan in the 1930's, who published from it the first edition of "A Finding List for Observers of Eclipsing Variables" (Dugan 1934, Princeton Univ. Obs. Contrib. No. 15). Successive editions of FL were subsequently published by Pierce (1947, Princeton Univ. Obs. Contrib. No. 22), by Wood (1953, Univ. Pennsylvania Astron. Series, Vol. VIII), by Koch et al. (1963, Univ. Pennsylvania Astron. Series, Vol. IX), and by Wood et al. (1980, Univ. Pennsylvania Astron. Series, Vol. XII). The FL was conceived as an aid to observers of eclipsing variables in selecting an observing program efficiently from the collection of all known data in an easy-to-use format. Although this format has changed over the years to meet existing requirements, the basic information content remains the same. The current edition differs from previous ones in the extension of the magnitude limit at minimum light from 13 to 15. In earlier editions, a binary system was not included unless the editors were reasonably certain that the system was indeed an eclipsing or (rarely) an ellipsoidal variable. The fifth edition includes all systems that the editors were fairly certain are either eclipsing or radiometrically variable binaries. The catalog fields are Finding List number; star name; position (given in the original catalog in equinox 1900); blue magnitude at maximum light; bandpass of maximum light; depth of primary minimum in same bandpass; bandpass primary minimum; depth of secondary minimum and its bandpass; spectral class of star eclipsed at primary light and optional uncertainty character; spectral class of star eclipsed at secondary light; most recent reliable epoch of primary minimum; most recent orbital period; duration of primary minimum; duration of totality of primary minimum; BD, CoD, CPD, and HD number; alternate designations of system; and codes indicating the nature of the system. This database was created by the HEASARC in December 1997 based on a computer readable version of the catalog that was obtained from the CDS (their catalog VI/44): a few additions were made by the HEASARC that are listed in the HEASARC_Changes section of the present document. This is a service provided by NASA HEASARC .
This catalog was constructed at the Royal Greenwich Observatory in order to enlarge the Gliese (1957, Mitt. Astron. Rechen-Inst., Ser. A, No. 8) compilation. It contains data on stars nearer than 25 pc that were not included in that version of Gliese's catalog, plus some additional information that had been published after 1957 on stars which were present in the 1957 version of the Gliese catalog. The electronic version contains essentially all information given in Table Ia of the published Woolley catalog, plus positional data, and most cross references to other catalogs given in Table IIa. The notes flags in Table Ia are not included because the notes are not machine-readable. Omitted from Table IIa are the finding-chart indicators (Lowell G numbers or notes references) and miscellaneous cross identifications to other names and catalog identifiers. Tables Ib and IIb, containing 21 systems originally included in Gliese's (1957) catalog but for which revised parallaxes have placed them farther than 25 pc are not included in the electronic version. Data in the electronic version include the Gliese number (newly added stars by Woolley have numbers beginning with 9001, but new parallaxes have removed 9419 and added 9849 and 9850 from the < 25 parsecs sample), component identifications for multiple systems, parallaxes, annual proper motions, radial velocities, (U,V,W) space velocities, box orbit parameters (omega, e, i), spectral types, UBV data, absolute visual magnitudes, positions, GCTP (General Catalogue of Trigonometric Stellar Parallaxes) and its Supplement (Jenkins 1952, 1963) names, HD, DM, GCRV (General Catalogue of Stellar Radial Velocities, Publ. Carnegie Inst., Washington, No. 601, Wilson 1953) and other catalog identifiers, BS (= HR) (Hoffleit 1964) numbers, and remarks codes for spectroscopic binaries (SB), doubles, variables, etc. Note that there is an entry in this catalog for the Sun, for which many fields, such as RA and Dec, have not been populated. This table was recreated by the HEASARC in December 2002 based on the 21-Jul-1997 version of the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/V/32A">CDS Catalog V/32A</a>. This is a service provided by NASA HEASARC .
Wra 751 is a Luminous Blue Variable that lately exhibits strong changes in light and colour. We summarize the available photometry of Wra 751, present new photometric observations, and discuss these data with special attention on the systematic differences between the various data sources. In addition, we establish an empirical relationship between b-y and B-V for this class of stars. Wra 751 is a strong-active member of the S Dor class exhibiting very-long term S Doradus phases with an amplitude of about two magnitudes in V and a cycle length of several decades. The associated B-V colour-index amplitude is about 0.4mag. At this moment this LBV, which is the reddest member of the class, goes through the bright (and red) stage of a long-term S Dor cycle. The S Dor behaviour of this system shows some resemblance to the temporal characteristics of the Galactic LBV AG Car: time scales and amplitudes of light and colour variability are very similar.