Observations by German astronomer
Ernst Zinner in 1929 gave indications that this may be a
variable star. It was listed in the New Catalogue of Suspected Variable Stars (1981) with a magnitude range of 3.74 to 3.81. Further observations up to 1991 showed a pattern of small, slow variations with a magnitude variation of 0.05. These appeared to repeat semi-regularly with a period of 183.6 days, although the spectroscopic data presented a longer period of 165.9 days.[15]
Name
It was a member of indigenous Arabic
asterismal-Nasaq al-Sha'āmī, "the Northern Line" of al-Nasaqān "the Two Lines",[16] along with
β Her (Kornephoros),
γ Ser (Zheng, Ching) and
β Ser (Chow).[17]
According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, al-Nasaq al-Sha'āmī or Nasak Shamiya were the title for three stars :
β Ser as Nasak Shamiya I,
γ Ser as Nasak Shamiya II, γ Her as Nasak Shamiya III (exclude
β Her)[18]
^
abcNicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49,
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1978A&AS...34....1N
^Gray, R. O.; Garrison, R. F. (1989), "The early F-type stars – Refined classification, confrontation with Stromgren photometry, and the effects of rotation", Astrophysical Journal Supplement Series, 69: 301,
Bibcode:
1989ApJS...69..301G,
doi:
10.1086/191315
^Samus, N. N.; Durlevich, O. V.; et al. (2009), "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)", VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S, 1,
Bibcode:
2009yCat....102025S
^
abcMassarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231,
Bibcode:
2008AJ....135..209M,
doi:10.1088/0004-6256/135/1/209
^
abBernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1): 1,
Bibcode:
1970CoAsi.239....1B
^Mason, Brian D.; et al. (December 2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471,
Bibcode:
2001AJ....122.3466M,
doi:10.1086/323920
^Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777,
Bibcode:
2005A&A...431..773R,
doi:10.1051/0004-6361:20042039
^Bakos, G. A.; Tremko, J. (1991), "Photometry and spectroscopy of Gamma Herculis", Contributions of the Astronomical Observatory Skalnate Pleso, 21: 7–14,
Bibcode:
1991CoSka..21....7B
^Kunitzsch, P.; Smart, T. (2006), A Dictionary of Modern Star names: A Short Guide to 254 Star names and Their Derivations (Second Revised ed.), Cambridge, MA: Sky Publishing, p. 31,
ISBN1-931559-44-9