The brightest stars in nearby galaxies. VIII - Cepheids and bright stars in NGC 3109

Abstract

view Abstract Citations (48) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Brightest Stars in Nearby Galaxies. VIII. Cepheids and Bright Stars in NGC 3109 Sandage, Allan ; Carlson, George Abstract Cepheid variables have been found in the nearby Sm IV galaxy NGC 3109. Periods for 29 of the variables, determined from blue plates taken over a 4 yr interval with the duPont 2.5 m reflector at Las Campanas, range from 31 to 5 days. The period-luminosity relation is well defined, showing the intrinsic scatter in magnitude at a given period due to the width of the instability strip. As expected, the P-L relation has a shallower slope than that of the standard calibration, caused by observational selection bias near the plate limit. The apparent blue distance modulus is (m-M)_AB_=26.4, based on the P-L zero point adopted in the text. The brightest supergiants, found by blinking blue and yellow plates, have absolute magnitudes of M_B_(3)= -7.6 for the mean of the three brightest blue stars, and M_V_(3)= -7.7 for the corresponding mean of the three brightest red stars. The first ten brightest red supergiant candidates are variable, ensuring membership. These absolute magnitudes agree with the previous calibration of the brightest red and blue star luminosities as a function of the absolute magnitude of the parent galaxy. Publication: The Astronomical Journal Pub Date: November 1988 DOI: 10.1086/114911 Bibcode: 1988AJ.....96.1599S Keywords: Blue Stars; Cepheid Variables; Red Giant Stars; Stellar Luminosity; Supergiant Stars; Color-Magnitude Diagram; Light Curve; Local Group (Astronomy); Magellanic Clouds; Stellar Magnitude; Stellar Spectrophotometry; Astronomy; GALAXIES: INDIVIDUAL; GALAXIES: STELLAR CONTENT; GALAXIES: DISTANCES; STARS: CEPHEIDS full text sources ADS | data products NED (25) SIMBAD (6) Related Materials (8) Part 1: 1976AJ.....81..743S Part 2: 1983AJ.....88.1569S Part 3: 1984AJ.....89..621S Part 4: 1984AJ.....89..630S Part 5: 1985AJ.....90.1019S Part 6: 1985AJ.....90.1464S Part 7: 1986AJ.....91..496S Part 9: 1996AJ....111.1872S