내용
사진
사진 업로드
DSS Images Other Images
관련 글
Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars
We present interferometric angular sizes for 12 stars with knownplanetary companions, for comparison with 28 additional main-sequencestars not known to host planets. For all objects we estimate bolometricfluxes and reddenings through spectral-energy distribution (SED) fits,and in conjunction with the angular sizes, measurements of effectivetemperature. The angular sizes of these stars are sufficiently smallthat the fundamental resolution limits of our primary instrument, thePalomar Testbed Interferometer, are investigated at thesub-milliarcsecond level and empirically established based upon knownperformance limits. We demonstrate that the effective temperature scaleas a function of dereddened (V – K)0 color isstatistically identical for stars with and without planets. A usefulbyproduct of this investigation is a direct calibration of the TEFF scale for solarlike stars, as a function of both spectraltype and (V – K)0 color, with an precision of\overline{\Delta T}_{\it {(V-K)}_0} = 138\,K over the range (V –K)0 = 0.0-4.0 and \overline{\Delta T}_{SpType} = 105\,K forthe range F6V-G5V. Additionally, in an Appendix we provide SED fits forthe 166 stars with known planets which have sufficient photometryavailable in the literature for such fits; this derived "XO-Rad"database includes homogeneous estimates of bolometric flux, reddening,and angular size.
| New Estimates of the Solar-Neighborhood Massive Star Birthrate and the Galactic Supernova Rate
The birthrate of stars of masses >=10 Msolar is estimatedfrom a sample of just over 400 O3-B2 dwarfs within 1.5 kpc of the Sunand the result extrapolated to estimate the Galactic supernova ratecontributed by such stars. The solar-neighborhood Galactic-plane massivestar birthrate is estimated at ~176 stars kpc-3Myr-1. On the basis of a model in which the Galactic stellardensity distribution comprises a ``disk+central hole'' like that of thedust infrared emission (as proposed by Drimmel and Spergel), theGalactic supernova rate is estimated at probably not less than ~1 normore than ~2 per century and the number of O3-B2 dwarfs within the solarcircle at ~200,000.
| The Carina Spiral Feature: Strömgren-Hβ photometry approach. I. The photometric data-base
A data-base collating all uvbybeta photometry available at present forO-B9 stars brighter than 10th visual magnitude in the field of theCarina Spiral Feature is presented. The completeness and homogeneity ofthe data-base are discussed.Based on CDS data.Table 1 is only available in electronic form at the CDS via anonymousftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/410/523
| Catalog of Galactic OB Stars
An all-sky catalog of Galactic OB stars has been created by extendingthe Case-Hamburg Galactic plane luminous-stars surveys to include 5500additional objects drawn from the literature. This work brings the totalnumber of known or reasonably suspected OB stars to over 16,000.Companion databases of UBVβ photometry and MK classifications forthese objects include nearly 30,000 and 20,000 entries, respectively.
| Strömgren and Hβ photometry of O and B type stars in star-forming regions. III. Carina Spiral Feature
Strömgren and Hβ photometry of O and B type stars, generallybrighter than 9.5 mag is reported for the field of the Carina SpiralFeature. The observations are based on the PPM catalogue identificationsand are designed to improve the completeness of the existing uvbybetadata for the bright early-type stars in the field. We present new uvbyphotometry for 283 stars and Hβ photometry for 225 of them. Theseobservations are part of an ongoing effort to study the structure ofselected star-forming regions in the Milky Way by means of uvbybetaphotometry. A comparison of the new data to other uvbybeta data sets forthis field is presented. Based on data from the Strömgren AutomaticTelescope of the Copenhagen University Observatory, La Silla. Tables 1and 2 are only available in electronic form at the CDS via anonymous ftpto 130.79.128.5 or via http://cdsweb.u-strasbg.fr/Abstract.html
|
새 글 등록
관련 링크
새 링크 등록
다음 그룹에 속해있음:
|
관측 및 측정 데이터
천체목록:
|
