On the photometric variability of blue supergiants in NGC 300 and its impact on the Flux-weighted Gravity–Luminosity Relationship
نویسنده
چکیده
We present a study of the photometric variability of spectroscopically confirmed supergiants in NGC 300, comprising 28 epochs extending over a period of five months. We find 15 clearly photometrically variable blue supergiants in a sample of nearly 70 such stars, showing maximum light amplitudes ranging from Based on observations obtained with the 2.2m ESO/MPI telescope at the European Southern Observatory, as part of proposal 163.N-0210.
منابع مشابه
A new extragalactic distance determination method using the flux-weighted gravity of late B and early A supergiants
Stellar evolution calculations predict the flux-weighted gravity g/T 4 eff and absolute bolometric magnitude of blue supergiants to be strongly correlated. We use medium resolution multi-object spectroscopy of late B and early A supergiants in two spiral galaxies, NGC 300 and NGC 3621, to demonstrate the existence of such a relationship, which proves to be surprisingly tight. An analysis of hig...
متن کاملThe Wind Momentum - Luminosity relationship : blue supergiants in the spiral galaxy NGC 300
We have carried out the wind analysis of six A-type supergiants in NGC 300. The derived Wind Momentum-Luminosity Relationship is compared with that of Galactic and M31 blue supergiants and with theoretical models.
متن کاملQuantitative Spectroscopy of 24 A supergiants in the Sculptor galaxy NGC 3001: Flux weighted gravity luminosity relationship, metallicity and metallicity gradient
A quantitative spectral analysis of 24 A supergiants in the Sculptor Group spiral galaxy NGC 300 at a distance of 1.9 Mpc is presented. A new method is introduced to analyze low resolution (∼ 5Å) spectra, which yields metallicities accurate to 0.2 dex including the uncertainties arising from the errors in Teff (5%) and log g (0.2 dex). For the first time the stellar metallicity gradient based o...
متن کاملar X iv : a st ro - p h / 03 01 17 9 v 1 1 0 Ja n 20 03 Blue Supergiants as a Tool for Extragalactic Distances –
Blue supergiant stars can be exceptionally bright objects in the optical, making them prime targets for the determination of extragalactic distances. I describe how their photometric and spectroscopic properties can be calibrated to provide a measurement of their luminosity. I first review two well-known techniques, the luminosity of the brightest blue supergiants and, with the aid of recent sp...
متن کاملThe Araucaria Project: the Effect of Blending on the Cepheid Distance to Ngc 300 from Advanced Camera for Surveys Images1
We have used the Advanced Camera for Surveys aboard the Hubble Space Telescope to obtain F435W , F555W and F814W single-epoch images of six fields in the spiral galaxy NGC 300. Taking advantage of the superb spatial resolution of these images, we have tested the effect that blending of the Cepheid variables studied from the ground with close stellar neighbors, unresolved on the ground-based ima...
متن کامل