The constellation is not particularly bright, having no stars brighter than fourth magnitude. β Comae Berenices is the brightest star in the constellation, at magnitude 4.26. It is intrinsically only slightly brighter than the Sun, which gives us an idea of how faint the Sun would appear seen from 27 light years away.
The second brightest star in Coma Berenices is α Comae Berenices (4.32m), also called Diadem. The name represents the gem in Berenice's crown. It is a binary star, with two components of almost equal magnitude. Because the orbital plane is so close to the Earth's line of sight, it was long suspected of being an eclipsing binary, but it now appears that the orbital tilt is 0.1° relative to the line of sight, so the stars do not eclipse each other as seen from Earth.
The only other fourth magnitude star in Coma Berenices is γ Comae Berenices (4.36m).
Over 200 variable stars are known in Coma Berenices, although many of them are obscure. FK Comae Berenices, which varies between 8.14m and 8.33m over a period of 2.4 days, is the prototype for the FK Com class of variable stars. It is believed that the variability of FK Com stars is caused by large, cool spots on the rotating surfaces of the stars. FS Comae Berenices is a semiregular variable that varies between 5.3m and 6.1m over a period of 58 days. R Comae Berenices is a Mira variable star that varies between 7.1m and 14.6m over a period of 363 days.
|β Com||Al Ḍafīrah||Arabic||the curl|
|ρ Com||Shang Tseang||Chinese||higher army general|
|21 Com||Kissīn||Greek???||species of ivy|
M100 (NGC 4321) is a 9.4m spiral galaxy seen face-on. At 7 arcminutes across, it has the largest apparent size of any galaxy in the Virgo cluster. It is located about 56 million light-years away. Its diameter is over 120,000 light years, making it among the largest spiral galaxies in the Virgo cluster. Photographs reveal a brilliant core, two prominent spiral arms and an array of secondary ones, as well as several dust lanes.
M85 (NGC 4382) is a lenticular galaxy that is the northernmost outlier of the Virgo cluster. It is one of the brighter members of the cluster. M98 (NGC 4192) is a bright, elongated spiral that is seen nearly edge-on. It has a small nucleus and faint but vast spiral arms. M99 (NGC 4254), about 1.5° southeast of M98, is a bright, round spiral seen face-on. R.H. Allen called it the "Pinwheel nebula", although this name is more often applied to the Triangulum Galaxy.
M88 (NGC 4501) is a multi-arm spiral galaxy, seen about 30° from edge-on.
Due to the great distance to the cluster, most of the galaxies are only visible in large telescopes. The brightest members are NGC 4889 and NGC 4874, both of which are of thirteenth magnitude, with most of the other members being of fifteenth magnitude or dimmer. NGC 4889 is a giant elliptical galaxy.
M64 (NGC 4826) is known as the Black Eye Galaxy because of its prominent dark dust lane in front of the galaxy's bright nucleus. It is relatively nearby, at around 17 million light years away from Earth. Recent studies have revealed that the interstellar gas in the outer regions of the galaxy rotates in the opposite direction from that in the inner regions, leading astronomers to believe that at least one satellite galaxy had collided with it less than a billion years ago.
NGC 4565 is a spiral galaxy that is seen edge-on, and is called the "Needle Galaxy" for that reason. With an apparent length of 16 arcminutes, it has the largest apparent size of any galaxy seen edgewise from Earth. It appears quite thin and has a dark dust lane.
Coma Berenices has been known as a distinct asterism since the Hellenistic period. Eratosthenes referred to it as both "Ariadne's Hair" and "Berenice's Hair". Ptolemy referred to it as "the lock" (of hair); however, he did not list it as one of his 48 constellations, considering it as part of Leo. For many years, Coma Berenices was considered usually as the tuft in Leo's tail, or sometimes as part of Virgo.
During the 16th century, a few maps that were made of the sky pictured two new constellations, including Coma Berenices. Tycho Brahe, who is usually given credit for the creation of the constellation, listed it as a distinct constellation in his star catalogue of 1602, and it appeared in Johann Bayer's Uranometria of 1603.
Even though this constellation is a modern constellation, it is associated with a charming legend. It is one of the few constellations (with Scutum) to owe its name to a historical figure, in this case Queen Berenice II of Egypt, wife of Ptolemy III Euergetes (fl. 246 BC–221 BC), the king under whom Alexandria became an important cultural center.
Circa 243 BC, the king undertook a dangerous expedition against the Syrians, who had murdered his sister. Berenice swore to the goddess Aphrodite to sacrifice her famous long hair, of which she was extremely proud, if her husband returned safely. He did, and she had her hair cut and placed it in the goddess' temple.
By the next morning the hair had disappeared. To appease the furious king and queen (and save the lives of the temple priests), the court astronomer, Conon, announced that the offering had so pleased the goddess, that she had placed it in the sky. He indicated a cluster of stars that at the time were identified as Leo's tail, but which have since been called Berenice's Hair. (Cf. Gaius Julius Hyginus, Astronomica 2.24)