J/A+A/509/A70 Study of an eclipsing binary in M31 (Vilardell+, 2010)
The distance to the Andromeda galaxy from eclipsing binaries.
Vilardell F., Ribas I., Jordi C., Fitzpatrick E.L., Guinan E.F.
<Astron. Astrophys. 509, A70 (2010)>
=2010A&A...509A..70V 2010A&A...509A..70V
ADC_Keywords: Galaxies, nearby ; Binaries, eclipsing ; Radial velocities
Keywords: stars: binaries: eclipsing - stars: fundamental parameters -
stars: distances - cosmology: distance scale -
galaxies: individual: M31
Abstract:
The cosmic distance scale largely depends on distance determinations
to galaxies of the Local Group. In this sense, the Andromeda galaxy
(M31) is a key rung to better constrain the cosmic distance ladder. A
project was started in 1999 to firmly establish a direct and accurate
distance to M31 using eclipsing binaries (EBs). After the
determination of the first direct distance to M31 from EBs, the second
direct distance to an EB system is presented: M31V J00443610+4129194.
Light and radial velocity curves were obtained and fitted to derive
the masses and radii of the components. The acquired spectra were
combined and disentangled to determine the temperature of the
components. The analysis of the studied EB resulted in a distance
determination to M31 of (m-M)0=24.30±0.11mag. This result, when
combined with the previous distance determination to M31, results in a
distance modulus of (m-M)0=24.36±0.08mag (744±33kpc), fully
compatible with other distance determinations to M31. With an error of
only project.
Description:
Log of spectroscopic observations and heliocentric radial velocity
determinations (when available) used to determine the fundamental
properties of M31V_J00443610+4129194.
Objects:
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RA (2000) DE Designation(s)
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00 44 36.10 +41 29 19.4 M31V_J00443610+4129194 = D31 J004436.1+412919.6
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 49 9 Radial velocities of M31V_J00443610+4129194
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.3 --- HJD Heliocentric Julian date
13- 16 I4 s ExpTime Exposure time
18- 19 I2 --- S/N Signal-to-noise ratio
21- 25 F5.3 --- Phase Orbital phase
27- 32 F6.1 km/s RVp ? Radial velocity for primary
34- 37 F4.1 km/s e_RVp ? Radial velocity error for primary
39- 44 F6.1 km/s RVs ? Radial velocity for secondary
46- 49 F4.1 km/s e_RVs ? Radial velocity error for secondary
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Acknowledgements:
Francesc Vilardell, francesc.vilardell(at)ua.es
(End) F. Vilardell, [Univ. Barcelona, Spain], P. Vannier [CDS] 28-Jan-2010