V529 Andromedae

V529 Andromedae, also known as HD 8801, is a variable star in the constellation of Andromeda. It has a 13th magnitude visual companion star 15" away, which is just a distant star on the same line of sight.

V529 Andromedae

Observation data Epoch J2000      Equinox J2000
Constellation	Andromeda
Right ascension	01^h 27^m 26.6726^s[1]
Declination	+41° 06′ 04.1831″[1]
Apparent magnitude (V)	6.46[2]
Characteristics
Spectral type	Am(kA5/hF1/mF2)[3]
U−B color index	0.03[2]
B−V color index	0.27[2]
V−R color index	0.26[2]
R−I color index	0.16[2]
Variable type	γ Doradus and δ Scuti[4]
Astrometry
Radial velocity (Rv)	0.8±0.3[5] km/s
Proper motion (μ)	RA: 9.820±0.084[1] mas/yr Dec.: 25.568±0.081[1] mas/yr
Parallax (π)	18.5729 ± 0.0435[1] mas
Distance	175.6 ± 0.4 ly (53.8 ± 0.1 pc)
Absolute magnitude (MV)	+2.68[5]
Details
Mass	1.55±0.1[5] M☉
Radius	1.7±0.1[5] R☉
Luminosity	6.5±0.6[5] L☉
Surface gravity (log g)	4.1±0.2[4] cgs
Temperature	7560±180[4] K
Rotational velocity (v sin i)	53.1±0.5[4] km/s
Other designations
SAO 37227, HIP 6794,HR 418, HD 8801, BD+40° 289.
Database references
SIMBAD	data

It is also an Am star with a spectral classification Am(kA5/hF1/mF2), meaning that it has the calcium K line of a star with spectral type A5, the Balmer series of a F1 star, and metallic lines of an F2 star.[3]

Variability

V529 Andromedae was the first star known to combine Gamma Doradus and Delta Scuti type pulsations.[5] Nine different pulsation frequencies have been observed, and three of them could arise from a previously unknown stellar pulsation mode.[6]

Companion

V529 Andromedae has a 13th magnitude companion about 15″ away.[7] It is a far more distant star than V529 And, only coincidentally aligned in the sky.[8]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. Mendoza, E. E.; et al. (1978). "UBVRI photometry of 225 AM stars". The Astronomical Journal. 83: 606–614. Bibcode:1978AJ.....83..606M. doi:10.1086/112242.
3. Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135–172. Bibcode:1995ApJS...99..135A. doi:10.1086/192182.
4. Neuteufel, R.; et al. (2013). "Abundance analysis of the γ Doradus-δ Scuti hybrid metallic line (Am) star HD 8801". Astronomische Nachrichten. 334 (7): 638–647. arXiv:1307.3497. Bibcode:2013AN....334..638N. doi:10.1002/asna.201311909.
5. Henry, Gregory W.; Fekel, Francis C. (2005). "HD 8801: A Unique Single Am Star with γ Doradus and δ Scuti Pulsations". The Astronomical Journal. 129 (4): 2026–2033. Bibcode:2005AJ....129.2026H. CiteSeerX 10.1.1.145.5743. doi:10.1086/428373.
6. Handler, G. (2009). "Confirmation of simultaneous p and g mode excitation in HD 8801 and γ Peg from time-resolved multicolour photometry of six candidate 'hybrid' pulsators". Monthly Notices of the Royal Astronomical Society. 398 (3): 1339–1351. arXiv:0904.4859. Bibcode:2009MNRAS.398.1339H. doi:10.1111/j.1365-2966.2009.15005.x.
7. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
8. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.