Eta Boötis

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**Eta Boötis**
Observation data Epoch J2000
Constellation (pronunciation)	Boötes
Right ascension	13^h 54^m 41.1^s
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
Variable type	None
Astrometry
Radial velocity (R_v)	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)
Absolute magnitude (M_V)	2.38
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.

Eta Boötis (η Boo / η Boötis) is a star in the constellation Boötes. It also has the traditional names Muphrid or Mufrid (Arabic for "the particular") or Saak and the Flamsteed designation 8 Boötis.

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. However the companion has not been resolved through speckle interferometery.

The star 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 Sol system. The two stars are about 3.24 light years apart [1], and each would appear brightly 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 Muphrid, while Muphrid 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.

[edit] Eta Boötis in fiction

In the RPG 2300ad, published by GDW, Eta Boötis is an important system, with a habitable moon named Aurore orbiting a Brown dwarf which orbits Eta Boötis. Due to the limited distance starships can travel in this fictional universe, Eta Boötis lies at juncture in the frontier with an alien race called Kafers. 2300ad was designed with the gliese 2 starmap, now outdated. The same starflight rules applied to the gliese 3 starmap would not result in the same starship routes.