Eta Arietis

From Conservapedia
Jump to: navigation, search
Eta Arietis
Observational Data
Designation 17 Arietis
η Ari
HD 13555
Right ascension 02h 12m 48.0856s[1][2]
Declination +21° 12′ 39.5775″[1][2]
Constellation Aries
Type of object Main sequence star
Magnitude Apparent Mag: +5.23[3]
Absolute Mag: 2.84 / 2.93[3]
Distance from Earth 94.16 ly[3]
Radial velocity 5.506 ± 0.0009 km/s[1][4]
Proper motion RA: 163.917 mas/yr[1][2]
Dec: 5.000 mas/yr[1][2]
Parallax 33.3383 ± 0.1196 mas[1][2]

Eta Arietis (17 Arietis, η Ari, HD 13555) is a main sequence star in the constellation of Aries, the ram.[5] It is one of the closest stars to the Sun at just 94.16 light years from Earth. Its name comes from the Bayer method of naming stars. The Greek first letter indicates the brightness of the star compared to other stars in the constellation, with higher letters indicating dimmer stars. As such, Eta Arietis is one of the dimmer stars in the constellation. It can be observed with the unaided eye in the Northern hemisphere, but its faintness means that dark skies with little to no light pollution are required.

The star is thought to be quite similar to the Sun, with a radius 1.91 larger and a surface temperature slightly higher at 6,500 kelvin.[3] These combine to mean Eta Arietis emits 6 times more radiation than Sol.


  1. 1.0 1.1 1.2 1.3 1.4 1.5 Eta Arietis. Simbad Astronomical Database. Retrieved on July 16, 2020.
  2. 2.0 2.1 2.2 2.3 2.4 Gaia Collaboration (2018). "VizieR Online Data Catalog: Gaia DR2". VizieR Online Data Catalog I/345: I/345. Bibcode2018yCat.1345....0G.  arXiv:0708.1752
  3. 3.0 3.1 3.2 3.3 Eta Arietis (17 Arietis) Star Facts. Retrieved on July 16, 2020.
  4. Soubiran, C.; Jasniewicz, G.; Chemin, L. et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars.". Astronomy and Astrophysics 616A (8). doi:10.1051/0004-6361/201832795. Bibcode2018A&A...616A...7S.  arXiv:1804.09370
  5. Eta Arietis. Retrieved on July 16, 2020.