#alpha geminorum

In order of brightness:

Pollux (β Geminorum) is the brightest star in the constellation. It is an orange giant star about 34 light years from Earth. In 2006, an exoplanet was possibly detected around Pollux; it was named Thestias. The name, like Castor (α Geminorum) below, comes from the story of Castor and Pollux in Greek mythology.

Castor (α Geminorum) is the second-brightest star in the constellation. This is a sextuple star system about 49 light years from Earth. The system consists of two blue-white giants and four red dwarf stars.

Alhena (γ Geminorum) is a binary star consisting of a blue-white giant star and a yellow star like our Sun. The whole system is about 109 light years away. The name comes from the Arabic word Al Han'ah meaning "the brand."

Tejat (μ Geminorum) is a solitary red giant star about 230 light years from Earth. The name comes from the Arabic word tiḥyāt although the meaning of this word has been lost.

Mebsuta (ε Geminorum) is yellow-orange supergiant star about 860 light years from Earth. It is over 130 times the size of the Sun! The name comes from the Arabic word Mabsūṭah meaning "outstretched paw."

Propus (η Geminorum) is a triple star system consisting of a red giant, a blue-white star, and a yellow giant. The entire system is about 380 light years away. The name comes from the Greek word propus meaning "forward foot."

Alzirr (ξ Geminorum) is a blue-white giant star about 59 light years from Earth. Its name comes from the Arabic word al-zirr meaning "the button."

Wasat (δ Geminorum) is a triple star system consisting of at least a white giant star and a red dwarf. The entire system is about 60 light years from Earth. The name comes from the Arabic word for "middle."

κ Geminorum is a binary star system with the primary being a yellow-orange giant star. The system lies about 141 light years away. In Chinese astronomy, the star has the name Jīxīn (積薪) meaning "pile of firewood."

λ Geminorum is a potential multiple star system. The primary star is a blue-white giant star about 101 light years away.

θ Geminorum is a single blue-white giant star about 189 light years away.

ι Geminorum is a single yellow-orange giant star about 120 light years away. In Chinese astronomy, it has the name Wu Zhū Hóu sān (五諸侯三) meaning "third star of the five feudal kings."

Mekbuda (ζ Geminorum) is yellow-white supergiant star about 1,120 light years from Earth. Its name comes from an Arabic phrase meaning "the lion's folded paw."

ν Geminorum is a triple star system consisting of at least two blue giant stars. The system is about 540 light years away. One star catalog gave it the name Nucatai, which comes from the Arabic word Al Nuḥātai meaning "the camel's hump."

The two bright stars are Castor (blue) and Pollux (white). Pollux (β Geminorum) and Castor (α Geminorum) are named after the two twins from Greek mythology. Their mother was the mortal Leda, but they shared different fathers. Castor was the mortal son of Tyndareus, king of Sparta, while Pollux was the divine son of Zeus. Pollux asked Zeus to share his immortality with Castor and so they were transformed into the constellation of Gemini.

Other bright stars included in this image are (ordered from bright to dim):

Alhena (γ Geminorum), named after the Arabic phrase Al Han'ah, meaning "the brand [on the neck of the camel]". This is a binary system with the primary being a blue-white subgiant star.

Mebsuta (ε Geminorum), named after the Arabic word Mabsūṭah, referring to an outstretched lion's paw. This is a white supergiant star.

Alzirr (ξ Geminorum), named after the Arabic word al-zirr, meaning "the button." This is a potential binary system, with the primary being a white subgiant star.

Wasat (δ Geminorum), derived from an Arabic word meaning "middle." This is a triple star system, with the primary being a white subgiant star.

κ Geminorum, a white giant star in a binary system.

λ Geminorum, a blue-white giant star in a possible binary system.

θ Geminorum, a single blue-white subgiant star.

Mekbuda (ζ Geminorum), named after an Arabic phrase meaning "the lion's folded paw." It shares this derivation with ε Geminorum. This star is a white supergiant star.

υ Geminorum, a single red giant star.

τ Geminorum, a single red giant star with a Jupiter-mass exoplanet.

Here's an image to help you identify these stars!

Rasalgethi (α Herculis) is a true multiple star system, a triple star system. The name comes from the Arabic phrase ra'is al-jāthī meaning "head of the kneeler," the "kneeler" being Hercules.

Polaris (α Ursae Minoris) is another true triple star system. The name comes from Neo-Latin stella polaris meaning, unsurprisingly, "polar star."

Mizar (ζ Ursae Majoris) is a quadruple star system, with each pair being seen as a "single" star. The name comes from the Arabic word mi'zar meaning "apron, wrapper, or covering."

Almach (γ Andromedae) is a quadruple star system. The name comes from the Arabic word al-'anāq meaning "the caracal," also known as a desert lynx.

Albireo (β Cygni) is probably a visual binary, meaning the two stars just happen to be close to each other on the sky. The name has an uncertain origin, tracing back to Ptolemy.