Mesarthim (γ Ari)

Mesarthim (γ Ari) is a double star in the constellation Aries, magnitude 4.5.

An easy pair of near-twin white stars, one of the first doubles discovered with a telescope (Robert Hooke, 1664). Its components (magnitudes 4.5 and 4.6; spectral types A2 IV (white) and B9 V (blue-white)) lie 7.3″ apart at PA 1° (measured 2024).

When and where to see it

It is best placed in the evening sky around November, when it crosses the meridian at about 10 pm local time (around midnight in October). It can be seen from everywhere north of 71°S and never sets north of 71°N.

At its highest it stands 59° up from 50°N, 74° up from 35°N, 71° up from the equator, 36° up from 35°S.

Facts

Type

Double star

Constellation

Aries

Designations

γ Ari, Gamma Arietis, γ¹ Ari, Gamma¹ Arietis, 5 Ari, 5 Arietis, STF 180, HIP 8832

Magnitude

4.5

Position

RA 1h 53.5m, Dec +19° 18′ (J2000)

Open AstroPilot to see when Mesarthim (γ Ari) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view.