The Brightest Stars in Nearby Galaxies - Part Four - the Color / Magnitude Diagram for the Brightest Red and Blue Stars in NGC2403

Abstract

view Abstract Citations (58) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The brightest stars in nearby galaxies. IV. The color-magnitude diagram for the brightest red and blue stars in NGC 2403. Sandage, A. Abstract Photometry of the brightest uncrowded supergiants in NGC 2403 shows that the most luminous blue stars are irregular variables, the brightest of which reaches B = 18.2, V = 17.9 at maximum. The two and three brightest such variables have (B (2) = 18.0 and (B (3)) = 18.2 giving (MB(2)) = - 9.9 and (MB(3)) = - 9.7, using (m - M )ABNGC 2403 = 27.9 obtained from the known data for 17 Cepheids and of the P-L relation at maximum. Identification of the brightest red supergiants is more uncertain due to the question of membership. Two candidate stars brighter than V= 19.4 and 19.8 are possible members, and five others brighter than V = 20 are less certain candidates. The red supergiants that are definitely members, as identified by their variability, begin at V = 20. The brightest candidates give (M(3)) = - 8.4 or (Mv(3) = - 7.7 as the calibration for the red supergiants. A summary is given of the presently available data for the absolute magnitudes of the brightest blue and red stars in galaxies whose distances are known from Cepheids. A clear trend of increasing luminosity of both the red and the blue brightest stars with increasing brightness of the parent galaxies is present, but it is significantly more shallow than the distance-degenerate line, showing that the brightest resolved stars in galaxies remain important distance indicators. Publication: The Astronomical Journal Pub Date: May 1984 DOI: 10.1086/113559 Bibcode: 1984AJ.....89..630S full text sources ADS | data products SIMBAD (75) NED (27) Related Materials (8) Part 1: 1976AJ.....81..743S Part 2: 1983AJ.....88.1569S Part 3: 1984AJ.....89..621S Part 5: 1985AJ.....90.1019S Part 6: 1985AJ.....90.1464S Part 7: 1986AJ.....91..496S Part 8: 1988AJ.....96.1599S Part 9: 1996AJ....111.1872S