Beta Ceti (β Ceti, abbreviated Beta Cet, β Cet), officially named Diphda/ˈdɪfdə/,[13] is the brightest star in the constellationofCetus. Although designated 'beta', it is actually brighter than the 'alpha' star in the constellation, Menkar, by half a magnitude. This orange giant is easy to identify due to its location in an otherwise dark section of the celestial sphere. Based on parallax measurements, it lies at an estimated distance of 96.3 light-years (29.5 parsecs) from the Sun.[1]
The effective temperature of the star's outer envelope is about 4,797 K,[10] giving it the characteristic orange hue of a K-type star.[16] In spite of its cooler temperature, Diphda is much more luminous than the Sun with a bolometric luminosity of about 145 times that of the Sun,[17] resulting from a radius 18[8] times as large as the Sun and a mass that is 2.8 times the Sun's mass.[7]
This star displays flaring activity that results in random outbursts that increase the luminosity of the star over intervals lasting several days. This is a much longer duration than for comparable solar flare activity on the Sun, which typically last for periods measured in hours.[14] In 2005, a relatively high rate of X-ray emission was detected with the XMM-Newton space observatory.[7] It is emitting about 2,000 times the X-ray luminosity of the Sun, allowing the star to be imaged with the Chandra X-ray Observatory.[15]
It bore the traditional names Diphda and Deneb Kaitos/ˌdɛnɛbˈkeɪtɒs/.[18]DiphdaisArabic for 'frog', from the phrase ضفدع الثانيaḍ-ḍifdaʿ aṯ-ṯānī 'the second frog' (the first frog' is Fomalhaut); Deneb Kaitos is from الذنب القيتوس الجنوب Al Dhanab al Ḳaiṭos al Janūbīyy 'southern tail of Cetus'.[19]
In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[20] to catalogue and standardize proper names for stars. The WGSN approved the name Diphda for this star on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.[21]
InChinese astronomy, Deneb Kaitos is called 土司空, Pinyin: Tǔsīkōng, meaning Master of Constructions, because this star is marking itself and stands alone in the Master of Constructions asterism, Legs mansion (see : Chinese constellation).[22] 土司空 (Tǔsīkōng), westernized into Too Sze Kung by R.H. Allen and the meaning is "Superintendent of Earthworks."[23]
^ abcdJohnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
^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.
^Wielen, R.; et al. (1999). "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions". Veröff. Astron. Rechen-Inst. Heidelb. 35 (35). Astronomisches Rechen-Institut Heidelberg: 1. Bibcode:1999VeARI..35....1W.
^Elgarøy, Øystein; Engvold, Oddbjørn; Lund, Niels (March 1999). "The Wilson-Bappu effect of the MgII K line - dependence on stellar temperature, activity and metallicity". Astronomy and Astrophysics. 343: 222–228. Bibcode:1999A&A...343..222E.
^ abcdeSägesser, S. N.; Jordan, C. (March 2005). "Emission measures for the single giant β Ceti". In Favata, F.; Hussain, G. A. J.; Battrick, B. (eds.). Proceedings of the 13th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, held 5–9 July 2004 in Hamburg, Germany. European Space Agency. p. 931. Bibcode:2005ESASP.560..931S.
^Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN978-1-931559-44-7.
00h43m35.37090s, −17° 59′ 11.7827″
