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The Peak Brightness of SN 1895B in NGC 5253 and the Hubble Constant
The light curve of the Type Ia supernova SN 1895B (in NGC 5253) isimportant because Sandage et al. have measured a distance to the hostgalaxy by means of Cepheid variables and thus have derived the Hubbleconstant. However, the last time the supernova plates were measured wasin 1923, and the resultant photometry is inconsistent at the 0.8 maglevel. In this paper, I report on the results of my remeasurement of theold supernova plates with a scanning microdensitometer. I findB-magnitudes of >11.3 +/- 0.3, 8.36 +/- 0.07, 8.51 +/- 0.06, 8.54 +/-0.05, and 9.34 +/- 0.08 on JD 2,413,359, 2,413,383, 2,413,384,2,413,385, and 2,413,393, respectively. The last plate was a prismplate, for which I present a flux-calibrated spectrum, taken ~15 daysafter maximum. Even though only loose constraints can be placed on thelight curve shape, the firm limit on the peak magnitude (<8.49 +/-0.03) will provide a firm limit on the Hubble constant. The most likelyshape is that of the average Type Ia template of Leibundgut et al., forwhich the best-fit peak B-magnitude is 8.26 +/- 0.11. The deducedprobability distribution for H0 is peaked at 51 +/- 7 km s-1 Mpc-1, withextreme limits of 61 +/- 12 and 26 +/- 5 km s-1 Mpc-1.
| A catalog of far-ultraviolet point sources detected with the fast FAUST Telescope on ATLAS-1
We list the photometric measurements of point sources made by the FarUltraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 spaceshuttle mission. The list contains 4698 Galactic and extragalacticobjects detected in 22 wide-field images of the sky. At the locationssurveyed, this catalog reaches a limiting magnitude approximately afactor of 10 fainter than the previous UV all-sky survey, TDl. Thecatalog limit is approximately 1 x 10-14 ergs A sq cm/s,although it is not complete to this level. We list for each object theposition, FUV flux, the error in flux, and where possible anidentification from catalogs of nearby stars and galaxies. Thesecatalogs include the Michigan HD (MHD) and HD, SAO, the HIPPARCOS InputCatalog, the Position and Proper Motion Catalog, the TD1 Catalog, theMcCook and Sion Catalog of white dwarfs, and the RC3 Catalog ofGalaxies. We identify 2239 FAUST sources with objects in the stellarcatalogs and 172 with galaxies in the RC3 catalog. We estimate thenumber of sources with incorrect identifications to be less than 2%.
| A homogeneous catalog of new UBV and H-beta photometry of B- and A-type stars in and around the Scorpius-Centaurus OB association
B- and A-type stars in and near the Sco-Cen OB association areinvestigated with UBV and H-beta photometry to acquire data relevant tothe luminosity function of Sco-Cen. The measurements generally consistof two 10-s integrations of U, B, V, (W, N) filters, and theobservations are corrected iteratively for atmospheric extinction andinstrumental response. The data presented give the mean V magnitude,mean B-V, mean U-B, and the estimated uncertainties for these values.The catalog provides a homogeneous catalog of data for a large fieldwith stellar objects delineating membership to the association Sco-Cenand that affect the luminosity function of the aggregate.
| Walraven photometry of nearby southern OB associations
Homogeneous Walraven (VBLUW) photometry is presented for 5260 stars inthe regions of five nearby southern OB associations: Scorpio Centaurus(Sco OB2), Orion OB1, Canis Major OB1, Monoceros OB1, and Scutum OB2.Derived V and (B - V) in the Johnson system are included.
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Pozíciós és asztrometriai adatok
| Csillagkép: | Kentaur |
| Rektaszcenzió: | 13h38m50.36s |
| Deklináció: | -33°06'40.6" |
| Vizuális fényesség: | 6.983 |
| Távolság: | 332.226 parszek |
| RA sajátmozgás: | -17 |
| Dec sajátmozgás: | -7.2 |
| B-T magnitude: | 6.937 |
| V-T magnitude: | 6.98 |
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