Misplaced Pages

HR 178 is a probable binary star in the constellation Andromeda. Located approximately 124 parsecs (400 ly) distant, it is an evolved Am star with a combined apparent magnitude of 6.06, meaning that it can only be seen with the naked eye on dark, clear nights. The star is suspected of variability, possibly varying between magnitudes 6.04 and 6.06. The variable magnitude period of HD 3883 is about 9.17 min.

The spectrum of HR 178 has been extensively studied for establishing element abundances in the evolved Am stars. It is given a spectral class of kA5hF1mF2, meaning its spectral type is A5, F1, or F2, depending on the particular spectral lines examined. The evolutionary stage of the star, and its mass determined from comparison with theoretical evolutionary tracks, is not precisely determined. However, it is very close to the end of its main sequence evolution and the margin of error in its mass is only about 0.1 M_☉.

HR 178 has been suspected of being a binary star since 1938 when its spectrum was interpreted as being composite. The pair were resolved using speckle interferometry in 1983. The companion is modelled to be between 1.5 and 3 magnitudes fainter than the primary star. Although there have since been several failed attempts to resolve the pair, a tentative orbit has been calculated with a period of 21.26 years and an eccentricity of 0.5.

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. ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy & Astrophysics, 355: L27 – L30, Bibcode:2000A&A...355L..27H.
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. Bibcode:1995ApJS...99..135A. doi:10.1086/192182.
4. ^ VSX (18 January 2010). "NSV 258". AAVSO Website. American Association of Variable Star Observers. Retrieved 15 June 2013.
5. Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
6. ^ Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics. 546: 5. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774.
7. Hui-Bon-Hoa, A. (June 2000). "Metal abundances of field A and Am stars". Astronomy and Astrophysics Supplement Series. 144 (2): 203–209. Bibcode:2000A&AS..144..203H. doi:10.1051/aas:2000207. ISSN 0365-0138. S2CID 123151702.
8. ^ Soubiran, Caroline; et al. (2016), "The PASTEL catalogue: 2016 version", Astronomy & Astrophysics, 591: A118, arXiv:1605.07384, Bibcode:2016A&A...591A.118S, doi:10.1051/0004-6361/201628497, S2CID 119258214.
9. ^ Burkhart, C.; Coupry, M. F.; Faraggiana, R.; Gerbaldi, M. (2005). "The field Am and ρ Puppis-like stars: Lithium and heavier elements". Astronomy and Astrophysics. 429 (3): 1043. Bibcode:2005A&A...429.1043B. doi:10.1051/0004-6361:20040467.
10. Chagnon, François (2009). Searching for northern roap stars: the UBC-OAN photometric survey. University of British Columbia (Thesis). doi:10.14288/1.0099308. S2CID 124888408.
11. Hynek, J. A. (1938). "A survey of stars with composite spectra". Contributions of Perkins Observatory. 1: 10. Bibcode:1938CoPer...1...10H.
12. McAlister, H. A.; Hendry, E. M.; Hartkopf, W. I.; Campbell, B. G.; Fekel, F. C. (1983). "Speckle interferometric measurements of binary stars. VIII". The Astrophysical Journal Supplement Series. 51: 309. Bibcode:1983ApJS...51..309M. doi:10.1086/190851.
13. Bonneau, D.; Carquillat, J. M.; Vidal, J. L. (1984). "Observations d'etoiles doubles par interferometrie des tavelures AU T2m du PIC du Midi". Astronomy and Astrophysics Supplement Series. 58: 729. Bibcode:1984A&AS...58..729B.

v t e Constellation of Andromeda
Adhil Andromeda in Chinese astronomy List of Andromeda's satellite galaxies List of stars in Andromeda
Stars	Bayer α (Alpheratz) β (Mirach) γ (Almach) δ ε ζ η θ ι κ λ μ ν ξ (Adhil) ο π ρ σ τ υ (Titawin) φ χ ψ ω A b c υ Per (Nembus) Flamsteed 2 3 4 5 6 7 8 9 10 11 12 13 14 (Veritate) 15 18 22 23 26 28 32 36 39 41 44 45 47 55 56 58 59 63 64 65 66 6 Per Variable R T U W Z RT RV RX SU SW TU TW WZ XZ AB AC AD AE AF AR BM BX CC CG CN DS DX EG ET EU FF GO GP GQ GX GR GY HH HN IW KK KX KZ LL LN LP LQ OP OS OU PX PY QR QV QX V385 V428 V439 V455 V529 V807 HR 1 40 56 78 104 122 134 178 275 282 283 289 379 410 483 687 746 748 8884 8925 8950 8962 8973 9011 9074 9075 9105 HD 16175 (Buna) 222155 Other 3XMM J004232.1+411314 ADS 48 HAT-P-6 (Sterrennacht) HAT-P-16 HAT-P-19 HAT-P-28 M31-RV KELT-1 NGC 44 NGC 82 NGC 84 NGC 91 NGC 162 NGC 464 Qatar-3 Qatar-4 Qatar-5 PA-99-N2 WASP-1 WISE 0146+4234 WISE J0005+3737 WISE J004945.61+215120.0
Exoplanets 14 Andromedae b κ Andromedae b υ Andromedae b c d Gliese 15 Ab c HD 13931 b HD 16175 b HAT-P-6b HAT-P-32b WASP-1b WASP-33b Qatar-4b Qatar-5b
Star clusters	NGC 206 272 752 956 7686 Other Mayall II RBC EXT8
Nebulae	NGC 7662
Galaxies	Messier 32 110 NGC 5 11 13 19 20 21 27 39 43 48 49 51 67 68 69 70 71 72 74 76 79 80 81 83 85 86 90 93 94 96 97 108 109 112 140 149 160 169 181 183 184 214 218 226 228 229 233 243 252 258 260 262 280 304 317 389 393 404 425 431 477 512 513 523 528 529 531 536 542 561 605 620 668 679 687 700 703 704 705 708 709 710 712 714 717 721 732 753 759 801 812 834 891 906 910 911 912 913 920 937 980 995 996 999 1000 7640 7836 Numbered I II III IV V VIII IX X XI XVIII XIX XXI Other 3C 66A 3C 66B Andromeda Galaxy Arp 273 Donatiello I UGC 1840
Galaxy clusters Abell 262 NGC 68 group
Astronomical events GRB 101225A SN 1885A (S)
Category

• Andromeda (constellation)
• Henry Draper Catalogue objects
• Am stars
• Bright Star Catalogue objects
• Suspected variables
• Hipparcos objects
• Durchmusterung objects