Iota Ursae Majoris

Iota Ursae Majoris
Diagram showing star positions and boundaries of the Ursa Major constellation and its surroundings
Diagram showing star positions and boundaries of the Ursa Major constellation and its surroundings

Location of ι Ursae Majoris (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Major
Right ascension 08h 59m 12.45362s[1]
Declination +48° 02′ 30.5741″[1]
Apparent magnitude (V) 3.14[2]/10.1/10.3
Characteristics
Spectral type A7V(n)[3] + M3V + M4V[4]
U−B color index +0.08[2]
B−V color index +0.19[2]
Variable type Suspected
Astrometry
Radial velocity (Rv)+9.0[5] km/s
Proper motion (μ) RA: -441.29[1] mas/yr
Dec.: -215.32[1] mas/yr
Parallax (π)68.92 ± 0.16 mas[1]
Distance47.3 ± 0.1 ly
(14.51 ± 0.03 pc)
Absolute magnitude (MV)+2.31[6]
Orbit[7]
Primaryι UMa A
Companionι UMa BC
Period (P)2084 ± 15 yr
Semi-major axis (a)16.7 ± 0.3″
Eccentricity (e)0.90 ± 0.02
Inclination (i)54 ± 4°
Longitude of the node (Ω)134 ± 2°
Periastron epoch (T)B 2029 ± 1
Argument of periastron (ω)
(secondary)		23 ± 5°
Details
ι UMa Aa
Mass1.7 ± 0.1[4] M☉
Radius1.67[8] R☉
Luminosity8.98[8] L☉
Surface gravity (log g)4.30 ± 0.07[4] cgs
Temperature8,242[9] K
Metallicity [Fe/H]0.01±0.05[8] dex
Rotational velocity (v sin i)154[10] km/s
Age620[11] Myr
Bb
Mass1±0.3[4][12] M☉
ι UMa B
Mass0.35 ± 0.05[4] M☉
Radius0.46[13] R☉
ι UMa C
Mass0.30 ± 0.05[4] M☉
Radius0.43[13] R☉
Other designations
Talitha, ι Ursae Majoris, ι UMa, Iota UMa, 9 Ursae Majoris, BD+48 1707, FK5 335, GJ 331, HD 76644, HIP 44127, HR 3569, SAO 42630, WDS J08592+4803A,BC.[3]
Database references
SIMBADι UMa
ι UMa A
ι UMa BC
ARICNSι UMa A
ι UMa B
ι UMa C

Iota Ursae Majoris (ι Ursae Majoris, abbreviated Iota UMa, ι UMa), also named Talitha /ˈtælɪθə/,[14] is a star system in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of 3.14,[2] making it visible to the naked eye and placing it among the brighter members of this constellation. Based upon parallax measurements, it is located at a distance of 47.3 light-years (14.5 parsecs) from the Sun.

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  2. ^ a b c d Cite error: The named reference clpl4 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference simbad was invoked but never defined (see the help page).
  4. ^ a b c d e f Cite error: The named reference Zhuchkov2012 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. Retrieved 16 May 2017.
  8. ^ a b c Cite error: The named reference gaspar was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference draper was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference aaa463_2_671 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference apj653_1_675 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference kirkpatrick was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference predicted was invoked but never defined (see the help page).
  14. ^ "IAU Catalog of Star Names". Retrieved 28 July 2016.