Eta Boötis

Eta Boötis
Eta Boötis
Boötes Constellation
Location of η Boötis
Observation data
Epoch J2000      Equinox J2000
Constellation Boötes
Right ascension 13h 54m 41.1s
Declination +18° 23′ 55″
Apparent magnitude (V) 2.68
Characteristics
Spectral type G0 IV
U−B color index 0.20
B−V color index 0.58
R−I color index 0.2
Astrometry
Radial velocity (Rv) 1.0 km/s
Proper motion (μ) RA: -60.95 mas/yr
Dec.: -358.1 mas/yr
Parallax (π) 88.17 ± 0.75 mas
Distance 37 ± 0.3 ly
(11.34 ± 0.1 pc)
Details
Metallicity \begin{smallmatrix}\left[\frac{Fe}{H}\right]\ =\ 0.23\end{smallmatrix}[1]
Orbit
Companion CCDM 13547+1824 B
Period (P) 1.35297 yr
Semimajor axis (a) 112.6"
Inclination (i) 103°
Other designations
Muphrid, Mufride, Muphride, Mufrid, Saak, 8 Boötis, Gl 534, HR 5235, BD +19°2725, HD 121370, LTT 14060, GCTP 3175.00, SAO 100766, FK5 513, HIP 67927.
Database references
SIMBAD data
Data sources:
Hipparcos Catalogue,
CCDM (2002),
Bright Star Catalogue (5th rev. ed.)
Database references
SIMBAD data

Eta Boötis (η Boo, η Boötis) is a star in the constellation Boötes. It has the traditional names Muphrid and Saak,[citation needed] and the Flamsteed designation 8 Boötis.

The name Muphrid is from the Arabic مفرد الرامح mufrid ar-rāmiħ "the (single) one of the lancer". In Chinese, 右攝提 (Yòu Niè Dī), meaning "the Right Conductor", refers to an asterism consisting of Eta Boötis, Tau Boötis and Upsilon Boötis.[2] Consequently, Eta Boötis itself is known as 右攝提一 (Yòu Niè Dī yī, English: the First Star of the Right Conductor.)[3]

In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, this star was designated Ramih al Ramih (رمح حالرامح - rumḥ al rāmiḥ), which was translated into Latin as Lancea Lanceator, possibly meaning the lance of the lancer.[4]

Based on its spectra, Eta Boötis has a significant excess of elements heavier than hydrogen. In fact the ratio of iron to hydrogen is considered close to the upper limit for dwarf stars in the galactic disk. The star has also been identified as a spectroscopic binary with a period of 494 days, but the companion has not been resolved through speckle interferometry.

Eta Boötis appears close to the prominent star Arcturus (Alpha Bootis) in Earth's sky, and Arcturus is in fact its closest stellar neighbor, as both stars are nearly identical in distance from the Sun. The two stars are about 3.24 light years apart [1], and each would appear bright in the other's sky. Arcturus would appear as roughly magnitude -5.2 (about 120 times brighter than it appears from Earth, or close to twice the brightness of Venus) in the night sky of a hypothetical planet orbiting Eta Boötis, while Eta Boötis would appear at about magnitude -2.5 in the sky of a hypothetical planet orbiting Arcturus, or over twice the brightness of Sirius in our night sky.[citation needed]

References

  1. ^ T. V. Mishenina (1998). "The chemical compositions of two stars with enhanced metallicities". Astronomy Reports 42 (2): 174–179. Bibcode 1998ARep...42..174M. 
  2. ^ (Chinese) 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.
  3. ^ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.
  4. ^ Knobel, E. B. (June 1895). "Al Achsasi Al Mouakket, on a catalogue of stars in the Calendarium of Mohammad Al Achsasi Al Mouakket". Monthly Notices of the Royal Astronomical Society 55: 429. Bibcode 1895MNRAS..55..429K. 

External links

v · Boötes
Bayer
Flamsteed
Nearby
  • Wolf 498
  • ξ
  • SDSS J1416+13


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