Beta Delphini
{{Short description|Binary star in the constellation of Delphinus}}
{{Starbox begin
| name = β Delphini
}}
{{Starbox image
| image=
{{Location mark
|image=Delphinus constellation map.svg|alt=|float=center|width=240
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=β Delphini
|x=411|y=375
}}
|caption=Location of β Delphini (circled)
}}
{{Starbox observe
| epoch = J2000
| equinox = J2000
| dec = {{DEC|+14|35|42.3195}}
| appmag_v = {{val|3.617|0.016}} {{nowrap|(4.11 + 5.01)}}
| constell = Delphinus
}}
{{Starbox character
| class = {{nowrap|F5 III + F5 IV}}
| b-v = A: {{val|0.43|0.14}}
B: {{val|0.56|0.25}}
| u-b =
| variable =
}}
{{Starbox astrometry
| component1 = Beta Delphini A
| radial_v =
| parallax = 32.33
| p_error = 0.47
| absmag_v = {{val|1.58|0.12}}
| component2 = Beta Delphini B
| absmag_v2 = {{val|2.79|0.14}}
}}
{{Starbox orbit
| period = 26.660
| axis = 0.440
| eccentricity = 0.36
| inclination = 61
| node = 177
| periastron = {{val|1989.50|u=yr}}
| periarg = 349
}}
{{Starbox detail
| component1 = Beta Delphini A
| radius =
| age_gyr = {{val|1.79|+0.17|-0.72}}
| component2 = Beta Delphini B
}}
{{Starbox catalog
| names = Rotanev, Rotanen, Venator, β Del, Beta Delphini, Beta Del, 6 Delphini, 6 Del, BD+14 4369, HD 196524, HIP 101769, HR 7882, SAO 106316, WDS 20375+1436AB.
}}
{{Starbox reference
|Simbad=bet+Del
}}
{{Starbox end}}
Beta Delphini (β Delphini, abbreviated Beta Del, β Del) is a binary star in the constellation of Delphinus. It is the brightest star in Delphinus.
The two components of the system are designated Beta Delphini A (officially named Rotanev {{IPAc-en|'|r|ou|t|@|n|E|v}}, which is historically the name of the system){{cite book
|last1=Kunitzsch |first1=Paul
|last2=Smart |first2=Tim
|date = 2006 |edition = 2nd rev.
|title = A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations
|publisher = Sky Pub |location = Cambridge, Massachusetts
|isbn = 978-1-931559-44-7
Nomenclature
β Delphini (Latinised to Beta Delphini) is the binary's Bayer designation. The designations of the two components as Beta Delphini A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).{{cite arXiv |title=On the naming convention used for multiple star systems and extrasolar planets |date=2010 |eprint=1012.0707 |class=astro-ph.SR |last1= Hessman |first1=F. V. |last2= Dhillon |first2=V. S. |last3= Winget |first3=D. E. |last4= Schreiber |first4=M. R. |last5= Horne |first5=K. |last6= Marsh |first6=T. R. |last7= Guenther |first7=E. |last8= Schwope |first8=A. |last9= Heber |first9=U. }}
Beta Delphini bore an historical name, Rotanev, which arose as follows: Niccolò Cacciatore was the assistant to Giuseppe Piazzi, and later his successor as Director of the Palermo Observatory. The name first appeared in Piazzi's Palermo Star Catalogue. When the Catalogue was published in 1814, the unfamiliar names Sualocin and Rotanev were attached to Alpha and Beta Delphini, respectively. Eventually the Reverend Thomas Webb, a British astronomer, puzzled out the explanation.{{cite book|last1=Webb|first1=T.W.|title=Celestial Objects for Common Telescopes|date=1859|publisher=Longmans, Green and Co.|location=London|pages=193–194}} Cacciatore's name, Nicholas Hunter in English translation, would be Latinized to Nicolaus Venator. Reversing the letters of this construction produces the two names. They have endured, the result of Cacciatore's little practical joke of naming the two after himself. How Webb arrived at this explanation 45 years after the publication of the catalogue is still a mystery.{{cite web|last1=Hurn |first1=Mark |title=Secrets of the 1814 Palermo Star Catalogue |url=http://www.star-names.freeserve.co.uk/SECRETS2.HTM |website=The Story of Star Names |publisher=Mark Hurn, Institute of Astronomy Library, Univ. of Cambridge |access-date=11 May 2015 |archive-url=https://web.archive.org/web/20160304023454/http://www.star-names.freeserve.co.uk/SECRETS2.HTM |archive-date=4 March 2016 }}
In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN){{citation
| url=https://www.iau.org/science/scientific_bodies/working_groups/280/
| title=IAU Working Group on Star Names (WGSN)
| publisher=International Astronomical Union
| access-date=22 May 2016 | postscript=. }} to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.{{cite web | url=https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf | page=5 | title=WG Triennial Report (2015-2018) - Star Names |access-date=2018-07-14}} It approved the name Rotanev for the component Beta Delphini A on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.
In Chinese, {{lang|zh|瓠瓜}} ({{lang|zh-Latn|Hù Guā}}), meaning Good Gourd, refers to an asterism consisting of Beta Delphini, Alpha Delphini, Gamma2 Delphini, Delta Delphini, and Zeta Delphini.{{in lang|zh}} 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, {{ISBN|978-986-7332-25-7}}.
Properties
Beta Delphini was found to be a binary star system in 1873 by the American astronomer S. W. Burnham. The system consists of a pair of F-type stars that orbit each other with a period of 26.66 years and an eccentricity of 0.36. The plane of the orbit is inclined by an angle of 61° to the line of sight from the Earth. The two stars have an angular separation of about 0.44 arcseconds, making them a challenge to resolve with a telescope. The larger member of the pair is a giant star with 1.75 times the mass and 24 times the luminosity of the Sun, while the secondary component is a subgiant star that has 1.47 times the Sun's mass and around 8 times the Sun's luminosity. The system is around 1.8 billion years old.
See also
References
{{reflist|30em|refs=
{{citation | first1=Robert | last1=Burnham | title=Burnham's celestial handbook: an observer's guide to the universe beyond the Solar System | volume=2 | series=Dover Books on Astronomy | edition=2nd | publisher=Courier Dover Publications | year=1978 | isbn=0-486-23568-8 | page=820 | url=https://books.google.com/books?id=wB9uZ9lH5bgC&pg=PA820 }}
[http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=V/50/catalog&recno=7882 HR 7882], 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 October 1, 2008.
{{SIMBAD link|beta+del|HD 196524 -- Spectroscopic binary}}, database entry, SIMBAD. Accessed on line October 1, 2008.
Entry 20375+1436, [http://ad.usno.navy.mil/wds/wdsnewframe4.html The Washington Double Star Catalog] {{webarchive |url=https://web.archive.org/web/20080908010456/http://ad.usno.navy.mil/wds/wdsnewframe4.html |date=September 8, 2008 }}, United States Naval Observatory. Accessed on line October 1, 2008.
}}
External links
- {{Cite web|title = Special Stars: Rotanev|url = http://jumk.de/astronomie/special-stars/rotanev.shtml|website = jumk.de|access-date = 2015-08-23|first = Juergen|last = Kummer}}
{{Stars of Delphinus}}
{{Authority control}}
{{DEFAULTSORT:Beta Delphini}}