HD 98618

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HD 98618
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ursa Major
Right ascension 11h 21m 29s
Declination +58° 53′ 18″
Apparent magnitude (V) 7.66
Characteristics
Spectral type G5V
U−B color index  ?
B−V color index 0.642
Variable type none
Astrometry
Radial velocity (Rv) 16 km/s
Proper motion (μ) RA: 41.28 mas/yr
Dec.: 29.19 mas/yr
Parallax (π) 25.82 ± 0.86 mas
Distance 126 ly
(38.7 pc)
Absolute magnitude (MV) 4.74 ± 0.07
Details
Mass 1.02±0.03 M
Radius 1.00 R
Luminosity 1.06 ± 0.05 L
Temperature 5843 ± 30 K
Metallicity 1.05 sol
Rotation 24 days
Age 4210 ± 900 million years
Other designations
BD +59°1369, HIP 55459

Coordinates: Sky map 11h 21m 29s, +58° 53′ 18″

HD 98618 is a star 126 light years from Earth that is almost identical in most respects to the Sun; it has therefore been proposed as a candidate solar twin.[1] However, like the solar twin 18 Scorpii, HD 98618 has a lithium abundance significantly higher than that of the Sun ([Li/H] = +0.45 ± 0.08).[2] Meléndez & Ramírez (2007) have suggested that HD 98618 be considered a "quasi solar twin", since they have now identified a solar twin, HIP 56948, with lithium content identical within the observational error to the Sun's.

See also[edit]

References[edit]

  1. ^ Meléndez, J., & Dodds-Eden, K., & Robles, J. A. (2006). "HD 98618: A Star Closely Resembling Our Sun". The Astrophysical Journal 641 (2): L133–L136. arXiv:astro-ph/0603219. Bibcode:2006ApJ...641L.133M. doi:10.1086/503898. 
  2. ^ Meléndez, J., & Ramírez, I. (2007). "HIP 56948: A Solar Twin with a Low Lithium Abundance". The Astrophysical Journal 669 (2): L89–L92. arXiv:0709.4290. Bibcode:2007ApJ...669L..89M. doi:10.1086/523942. 

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