9 Andromedae
{{Short description|Star in the constellation Andromeda}}
{{about|the star|the galaxy|Andromeda IX}}
{{Starbox begin}}
{{Starbox image
| image=
{{Location mark
|image=Pegasus constellation map.svg|alt=|float=center|width=260
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=9 Andromedae
|x=370|y=36
}}
|caption=Location of 9 Andromedae (circled)
}}
{{Starbox observe
| epoch = J2000
| constell = Andromeda
| dec = {{DEC|+41|46|25.2031}}
}}
{{Starbox character
| type =
| class = A7 V or A7m
| u-b =
| variable = β Lyr
}}
{{Starbox astrometry
| parallax = 7.0976
| p_error = 0.0544
}}
{{Starbox orbit
| period_unitless = 3.2196 d
| eccentricity = 0.03
| periastron = {{Val|2436094.876|u=JD|fmt=commas}}
| k1 = 71.6
}}
{{Starbox detail
| component1 = 9 And A
| mass = 2.48
| radius = 3.51
| luminosity = 49.2
| temperature = 8,200
| metal_fe =
| gravity =
| age_gyr =
| component2 = 9 And B
| mass2 = 1.32
| luminosity2 = 17.5
| temperature2 = 6,330
}}
{{Starbox catalog
| names = {{odlist | F=9 And | V=AN And | BD=+40°5043 | HD=219815 | HIP=115065 | HR=8864 | SAO=52881 | PPM=64041 }}
}}
{{Starbox reference
| Simbad = 9+And
}}
{{Starbox end}}
Image:ANAndLightCurve.png for AN Andromedae, plotted from TESS data]]
9 Andromedae, abbreviated 9 And by convention, is a variable binary star system in the northern constellation Andromeda. 9 Andromedae is the Flamsteed designation, while it bears the variable star designation AN Andromedae, or AN And. The maximum apparent visual magnitude of the system is 5.98, which places it near the lower limit of visibility to the human eye. Based upon an annual parallax shift of {{Val|7.1|ul=mas}}, it is located 460 light years from the Earth.
This system was determined to be a single-lined spectroscopic binary in 1916 by American astronomer W. S. Adams, and the initial orbital elements were computed by Canadian astronomer R. K. Young in 1920. The pair orbit each other with a period of 3.2196 days and an eccentricity of 0.03. It is an eclipsing binary, which means the orbital plane is inclined close to the line of sight and, from the perspective of the Earth, the stars pass in front of each other, causing two partial eclipses every orbit. During the transit of the secondary in front of the primary, the visual magnitude drops to 6.16, while the eclipse of the secondary by the primary lowers the net magnitude to 6.09.
References
{{Reflist|refs=
{{cite simbad | title=9 And | access-date=September 14, 2018 }}
| title=MAST: Barbara A. Mikulski Archive for Space Telescopes
| url=https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html
| publisher=Space Telescope Science Institute | access-date=16 October 2022}}
| title=General catalogue of variable stars: Version GCVS 5.1
| last1=Samus' | first1=N. N. | last2=Kazarovets | first2=E. V.
| last3=Durlevich | first3=O. V. | last4=Kireeva | first4=N. N.
| last5=Pastukhova | first5=E. N. | journal=Astronomy Reports
| volume=61 | issue=1 | pages=80 | year=2017 | postscript=.
| doi=10.1134/S1063772917010085 | bibcode=2017ARep...61...80S | s2cid=125853869 }}
| title=XHIP: An extended hipparcos compilation
| last1=Anderson | first1=E. | last2=Francis | first2=Ch.
| journal=Astronomy Letters | arxiv=1108.4971
| volume=38 | issue=5 | pages=331 | year=2012
| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015
| s2cid=119257644 | postscript=. }}
| title=MK Classifications of some Northern Hemisphere Binary Systems
| last1=Hill | first1=G. | last2=Hilditch | first2=R. W.
| last3=Younger | first3=F. | last4=Fisher | first4=W. A.
| journal=Memoirs of the Royal Astronomical Society
| volume=79 | page=131 | year=1975 | postscript=.
| bibcode=1975MmRAS..79..131H | display-authors=1 }}
| title=Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i
| display-authors=1 | last1=Royer | first1=F.
| last2=Grenier | first2=S. | last3=Baylac | first3=M. -O.
| last4=Gómez | first4=A. E. | last5=Zorec | first5=J.
| journal=Astronomy and Astrophysics | postscript=.
| volume=393 | pages=897–911 | date=October 2002
| doi=10.1051/0004-6361:20020943 | bibcode=2002A&A...393..897R | arxiv=1201.2052 | s2cid=14070763 }}
| title=Eclipsing variables: Catalogue and classification
| display-authors=1 | last1=Avvakumova | first1=E. A.
| last2=Malkov | first2=O. Yu. | last3=Kniazev | first3=A. Yu.
| journal=Astronomische Nachrichten
| volume=334 | issue=8 | page=860 | date=October 2013
| doi=10.1002/asna.201311942 | bibcode=2013AN....334..860A | hdl=10995/27061 | hdl-access=free }}
| display-authors=1 | last1=Pourbaix | first1=D.
| last2=Tokovinin | first2=A. A. | last3=Batten | first3=A. H.
| last4=Fekel | first4=F. C. | last5=Hartkopf | first5=W. I.
| last6=Levato | first6=H. | last7=Morrell | first7=N. I.
| last8=Torres | first8=G. | last9=Udry | first9=S.
| title=SB9: The Ninth Catalogue of Spectroscopic Binary Orbits
| journal=Astronomy & Astrophysics | postscript=.
| year=2004 | pages=727–732 | volume=424
| bibcode=2004A&A...424..727P | doi=10.1051/0004-6361:20041213 | arxiv=astro-ph/0406573| s2cid=119387088 }}
| title=A Photometric Study of the Am Binary System AN Andromedae
| last1=Tremko | first1=Jozef | last2=Bakos | first2=Gustav A.
| journal=Journal of the Royal Astronomical Society of Canada
| volume=72 | page=263 | date=October 1978
| bibcode=1978JRASC..72..263T | postscript=. }}
}}
External links
- [http://aladin.u-strasbg.fr/AladinPreview?-c=23+18+23.3242%2B41+46+25.233&ident=V*+AN+And&submit=Aladin+previewer Image 9 Andromedae]
{{Stars of Andromeda}}
{{DEFAULTSORT:9 Andromedae}}