Gamma Andromedae

Gamma Andromedae (Gamma And / γ And / γ Andromedae) is the third brightest star in the constellation of Andromeda. It is also known by the traditional name Almach (also spelt as "Almaach", "Almaack", "Almak", or "Alamak"), from the Arabic "al-^canāq al-arđ̧". This Arabic phrase refers to the caracal, or desert lynx. [p. 23, "Star tales", Ian Ridpath, James Clarke & Co., 1989, ISBN 0718826957.] It was known as 天大將軍一 (the First Star of the Great General of the Heaven) in Chinese.

In the late 18th century, Johann Tobias Mayer discovered that γ Andromedae was a double star. When examined in a small telescope, it appears to be a bright, golden yellow star (γ¹ Andromedae) next to a dimmer, greenish-blue star (γ² Andromedae), separated by approximately 10 arcseconds. It is considered by stargazers to be a beautiful double star with a striking contrast of color.pp. 113–114, vol. 1, "Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System", Robert Burnham, New York: Courier Dover Publications, 1978, ISBN 048623567X.] It was later discovered that γ² Andromedae is itself a triple star system. What appears as a single star to the naked eye is thus a quadruple star system, approximately 350 light-years from the Earth. [ [http://vizier.cfa.harvard.edu/viz-bin/VizieR-5?-out.add=.&-source=J/A%2bAS/124/75/catalog&recno=53 01578+4151] , database entry, MSC - a catalogue of physical multiple stars, A. A. Tokovinin, CDS database ID [http://cdsarc.u-strasbg.fr/viz-bin/Cat?J/A%2bAS/124/75 J/A+AS/124/75] .]

γ¹ Andromedae

Starbox begin
name = γ¹ Andromedae
(γ Andromedae A)Starbox observe
epoch = J2000.0
equinox = J2000.0 (ICRS)
constell = Andromeda
ra = RA|02|03|53.9531SIMBAD link|gam01+and|NAME ALMACH -- Star in double system, database entry, SIMBAD. Accessed on line August 19, 2008.]
dec = DEC|+42|19|47.009
appmag_v=2.26Starbox character
class = K3IIb
u-b = +1.58 [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=V/50/catalog&recno=603 HR 603] , database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID [http://vizier.u-strasbg.fr/viz-bin/Cat?V/50 V/50] . Accessed on line August 19, 2008.]
b-v = +1.37
r-i = +0.68Starbox astrometry
radial_v = −11.7 ± 0.9
prop_mo_ra = 43.08
prop_mo_dec = −50.85
parallax = 9.19
p_error = 0.73
parallax_footnote =
absmag_v = −2.9From apparent magnitude and parallax.] Starbox detail
rotational_velocity = < 17
radius = 80 [http://www.astro.uiuc.edu/~kaler/sow/almach.html Almach] , Jim Kaler, "Stars". Accessed on line August 19, 2008.]
luminosity = 2,000
temperature = 4,500Starbox catalog
names=Almach, Almaach, Almak, Almaak, Alamak, γ¹ And, Gamma¹ Andromedae, Gamma¹ And, γ Andromedae A, γ And A, Gamma Andromedae A, Gamma And A, 57 Andromedae A, 57 And A, STF 205A, ADS 1630 A, BD+41 395, CCDM J02039+4220A, FK5 73, GC 2477, HD 12533, HIP 9640, HR 603, IDS 01578+4151 A, PPM 44721, SAO 37734, WDS 02039+4220A.Starbox reference
Simbad=gam01+and

γ¹ Andromedae is a bright giant star with a spectral classification of K3IIb. It has an apparent visual magnitude of approximately 2.26.

γ² Andromedae

Starbox begin
name = γ² Andromedae
(γ Andromedae BC)Starbox observe
epoch = J2000.0
equinox = J2000.0 (ICRS)
constell = Andromeda
ra = RA|02|03|54.720 (B) [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/239/h_dm_com&recno=1972 Component 2, HIP 9640] , database entry, Hipparcos catalogue, CDS ID [http://vizier.u-strasbg.fr/viz-bin/Cat?I/239 I/239] .]
dec = DEC|+42|19|51.41 (B)
appmag_v=4.84 (BC)
(combined)
5.5 (B)
6.3 (C)Starbox character
class = B9.5V/B9.5V (B)
(spectroscopic binary)
A0V (C)Entry 02039+4220, discoverer code STT 38BC, [http://ad.usno.navy.mil/wds/wdsnewweb1.txt The Washington Double Star Catalog] , United States Naval Observatory. Accessed on line August 19, 2008.]
u-b = −0.12 [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=V/50/catalog&recno=604 HR 604] , database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID [http://vizier.u-strasbg.fr/viz-bin/Cat?V/50 V/50] . Accessed on line August 19, 2008.]
b-v = +0.03Starbox astrometry
radial_v = −14 ± 5 (B)
prop_mo_ra = 37 (B)
prop_mo_dec = −57 (B)
parallax = 9.19
p_error = 0.73
parallax_footnote =
absmag_v = −0.3 (BC)Starbox visbin
reference = Entry 02039+4220, [http://ad.usno.navy.mil/wds/orb6/orb6frames.html Sixth Catalog of Orbits of Visual Binary Stars] , William I. Hartkopf & Brian D. Mason, United States Naval Observatory. Accessed on line August 21, 2007.]
period = 63.67 ± 1.0
axis = 0.302 ± 0.001
eccentricity = 0.927 ± 0.03
inclination = 109.8 ± 5.0
node = 109.6 ± 5.0
periastron = B2015.5 ± 1.5
periarg = 183.4 ± 15.0Starbox relpos
epoch = 2004
primary = γ¹ And
angdistsec = 9.6
angdistref =
posang = 63
posangref = Starbox catalog
names=γ² And, Gamma² Andromedae, Gamma² And, γ Andromedae BC, γ And BC, Gamma Andromedae BC, Gamma And BC, 57 Andromedae BC, 57 And BC, STT 38BC, ADS 1630 BC, CCDM J02039+4220BC, GC 2479, HD 12534, HIP 9640, HR 604, IDS 01578+4151 BC, SAO 37735, WDS 02039+4220BC.SIMBAD link|gam02+and|HD 12534 -- Spectroscopic binary, database entry, SIMBAD. Accessed on line August 19, 2008.] [ [http://simbad.u-strasbg.fr/simbad/sim-id?Ident=gam+and+c BD+41 395C -- Star in double system] , database entry, SIMBAD. Accessed on line August 21, 2008.] Entry 02039+4220, discoverer code STF 205, components A-BC, [http://ad.usno.navy.mil/wds/wdsnewweb1.txt The Washington Double Star Catalog] , United States Naval Observatory. Accessed on line August 27, 2008.] Starbox reference
Simbad=gam02+and

γ² Andromedae, with an overall apparent visual magnitude of 4.84, is 9.6 arcseconds away from γ¹ Andromedae at a position angle of 63 degrees. In October 1842, Wilhelm Struve found that γ² Andromedae was itself a double star whose components were separated by less than an arcsecond.p. 36–37, [http://books.google.com/books?id=5xQuAAAAIAAJ "Star-names and Their Meanings"] , Richard Hinckley Allen, New York: G. E. Stechert, 1899.] The components are an object of apparent visual magnitude 5.5, γ Andromedae B, and a type-A main sequence star with apparent visual magnitude 6.3, γ Andromedae C. They have an orbital period of about 64 years. Spectrograms taken from 1957 to 1959 revealed that γ Andromedae B was itself a spectroscopic binary, composed of two type-B main sequence stars orbiting each other with a period of 2.67 days.A Preliminary Study of the Spectroscopic Binary Gamma Andromedae B, L. A. Maestre and J. A. Wright, "Astrophysical Journal" 131 (January 1960), pp. 119–121, bibcode|1960ApJ...131..119M.]

Location

The star's location is shown in the following chart of the Andromeda constellation:

Visual companion

Starbox begin
name = CCDM J02039+4220D Starbox observe
epoch = J2000.0
equinox = J2000.0 (ICRS)
constell = Andromeda
ra = RA|02|03|51.74SIMBAD link|CCDM+J02039%2B4220D|CCDM J02039+4220D -- Star in double system, database entry, SIMBAD. Accessed on line August 19, 2008.]
dec = DEC|+42|19|35.4
appmag_v=15.0Starbox relpos
epoch = 1898
primary = γ¹ And
angdistsec = 27.9
angdistref =
posang = 245
posangref = Starbox reference
Simbad = CCDM+J02039+%2B4220DStarbox catalog
names=WDS 02039+4220D.

CCDM J02039+4220D, a star with apparent visual magnitude 15.0, has been observed 28 arcseconds away from γ¹ Andromedae.Entry 02039+4220, discoverer code BAR 22, components AD, [http://ad.usno.navy.mil/wds/wdsnewweb1.txt The Washington Double Star Catalog] , United States Naval Observatory. Accessed on line August 19, 2008.]

ee also

* Gamma Andromedae in fiction
* NGC 752

References

External links

* [http://www.alcyone.de/cgi-bin/search.pl?object=HR0603 Alamak] at Alcyone Software's Star Data Pages
* [http://www.daviddarling.info/encyclopedia/A/Almaak.html Almaak (Gamma Andromedae)] at "The Internet Encyclopedia of Science"
* [http://aladin.u-strasbg.fr/AladinPreview?02%2003%2053.95%20%2B42%2019%2047.0&ident=NAME%20ALMACH Image ALMACH]
*