Omega Eridani

{{Starbox begin

| name = ω Eridani}}

{{Starbox observe

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Eridanus

| ra = {{RA|04|52|53.66995}}

| dec = {{DEC|−05|27|09.6972}}

| appmag_v = 4.37

}}

{{Starbox character

| class = A9 IVn

| u-b = +0.12

| b-v = +0.26

| r-i =

}}

{{Starbox astrometry

| radial_v = −8.3

| prop_mo_ra = −17.86

| prop_mo_dec = +25.57

| parallax = 13.88

| p_error = 0.24

| parallax_footnote =

| absmag_v = 0.10

}}

{{Starbox detail

| mass =

| radius = 6.7

| luminosity = 69

| temperature = 6,878

| gravity = 3.4

| metal_fe = 0.18

| rotational_velocity = 186

| rotation =

| age_myr =

}}

{{Starbox catalog

| names = ω Eri, BD−05° 1068, 61 Eridani, HD 31109, HIP 22701, HR 1560, SAO 131568.

}}

{{Starbox reference

| Simbad = ome+Eri

}}

Omega Eridani (ω Eri) is a single star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude is 4.37. The distance to this star, as determined by the parallax method, is around 235 light years.

It is an A-type subgiant star with a stellar classification of A9 IVn, where the 'n' suffix indicates a broad ("nebulous") absorption due to rotation. The projected rotational velocity is 186 km/s. This gives the star an oblate shape with an equator that is 13% wider than the polar radius. The angular size of Omega Eridani is 0.87 mas. At an estimated distance of the star, this yields a physical size of around 6.7 times the radius of the Sun.

Omega Eridani was long thought to be a is a single-lined spectroscopic binary system, with an orbital period of 3,057 days (8.4 years) and an eccentricity of 0.46. However, newer and higher-quality radial velocity observations find no evidence for a companion, casting serious doubt on the status of Omega Eridani as a binary star.

References

{{reflist|refs=

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| postscript=. }} The radius (R_*) is given by:

: $\begin{align} 2\cdot R_*
& = \frac{(72\cdot 0.87\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\
& \approx 13.4\cdot R_{\bigodot}
\end{align}$

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