42 Draconis

42 Draconis / Fafnir

42 Draconis in optical light
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Draco
Right ascension 18h 25m 59.13696s[1]
Declination +65° 33′ 48.5313″[1]
Apparent magnitude (V) 4.82[2]
Characteristics
Spectral type K1.5 III[2]
B−V color index 1.187
Astrometry
Radial velocity (Rv)31.75±0.12[1] km/s
Proper motion (μ) RA: +105.816 mas/yr[1]
Dec.: −26.846 mas/yr[1]
Parallax (π)11.056 ± 0.0841 mas[1]
Distance295 ± 2 ly
(90.4 ± 0.7 pc)
Absolute magnitude (MV)–0.108
Details
Mass0.879±0.050[2] M☉
Radius21.25+0.41
−0.43[3] R☉
Luminosity142.55±5.77[2] L☉
Surface gravity (log g)1.86±0.04[4] cgs
Temperature4,367±46[4] K
Metallicity [Fe/H]−0.45±0.02[4] dex
Age13.19±1.92[2] Gyr
Other designations
Fafnir, BD+65° 1271, GC 25212, HD 170693, HIP 90344, HR 6945, SAO 17888, PPM 20916, GCRV 10941
Database references
SIMBADdata
Exoplanet Archivedata

42 Draconis (abbreviated 42 Dra), formally named Fafnir (/ˈfɑːvnər/ or /ˈfɑːfnɪər/),[5][6] is a 5th magnitude K-type giant star located approximately 295 light years away in the constellation of Draco. As of 2009, an extrasolar planet (designated 42 Draconis b, later named Orbitar) is thought to be orbiting the star.

Of spectral type K1.5III, the star has a mass similar to the Sun but with a radius 22 times greater. It is a metal-poor star with metallicity as low as 35% that of the Sun and its age is 9.49 billion years. It is the northern pole star of Venus.[7]

  1. ^ a b c d e Cite error: The named reference DR3 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Ligi2016 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference baines2018 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference soubiran was invoked but never defined (see the help page).
  5. ^ "Fafnir". Merriam-Webster.com Dictionary. Merriam-Webster.
  6. ^ "IAU Catalog of Star Names". Retrieved 28 July 2016.
  7. ^ ""Is Polaris the north star for all the other planets just like it is for Earth?" | Planetarium | University of Southern Maine". usm.maine.edu. Archived from the original on 2022-11-03. Retrieved 2022-07-12.