I associate April evenings with the arrival in the ENE of the bright orange star Arcturus, in the constellation Bootes, the Herdsman. A red giant, Arcturus is the fourth brightest star in the entire night sky. It’s 37 light years away — the light you see tonight is what Arcturus looked like in 1984.
Arcturus is Greek for ‘Guardian of the Bear,’ the ‘Bear’ being the neighboring constellation, Ursa Major (Latin for ‘Great Bear’). A curve following the tail of Ursa Major passes through Arcturus and leads to Spica, the brightest star in Virgo, the second largest constellation in the heavens.
During the entire month of April, for an hour or so after darkness falls, the Zodiacal Light is faintly visible in the west. The Zodiacal Light is sunlight reflecting off of small interplanetary particles.
Mars continues to fade as it moves to the opposite side of its orbit, as seen from Earth. During April, it’s visible in the west as it moves from Taurus into Gemini.
At the end of April, Mercury begins to climb out of strong evening twilight, becoming an easy evening object in May.
Just below Mercury in the twilight glare, Venus has also moved to the east of the Sun. It, too, will become an easy evening object, beginning in May.
Jupiter and Saturn are now morning objects, rising before dawn in the constellation Capricorn.
Coma Berenices is a constellation few pay attention to – it has no bright stars; it’s not on the ecliptic, so no planets pass through it; and there’s no pattern to its stars, unlike neighboring Leo’s lionesque profile. Yet, since moving to Santa Fe, Coma Berenices has become one of my favorite constellations.
The constellation looks like a faint sprinkle of stardust and our dark skies make Coma Berenices easy to see and appreciate — the constellation’s practically invisible in suburban and urban settings.
The reason Coma Berenices looks to some like an open star cluster is because part of the constellation is one. The Coma Star Cluster consists of about 40 stars, located in the northwest part of the constellation. The cluster is relatively close to our solar system, so the stars appear spread out, even to the unaided eye.
More importantly to astronomers, Coma Berenices is home to a large cluster of galaxies, known as the Coma Cluster. With over 1,000 galaxies, the Coma Cluster, along with the Leo Cluster, comprise the Coma Supercluster of galaxies. So, this seemingly barren part of the sky is chock-full of deep sky objects.
Until about 2,000 years ago, the stars comprising current day Coma Berenices were considered part of the constellation Leo. Coma Berenices was first recognized as a constellation in its own right in the 1500s. It’s the only modern-day constellation named for a historical figure: Berenice II.
Berenice II married Ptolemy III, becoming Queen of Egypt in 246 BC. The Egyptian people worshipped Berenice II as a goddess – she was considered the protector of sailors, helping them avoid fatal shipwrecks.
When Ptolemy III went to battle in the Third Syrian War, Berenice II said that if her husband safely returned, she’d cut off her long tresses as a votive offering. She placed her cut tresses in a temple, only to learn that her hair had disappeared by the following day. Ptolemy III’s court astronomer claimed that the goddess Aphrodite had placed the tresses in the sky, in honor of Berenice II’s ‘sacrifice’ (My wife recently cut my hair; the birds used my cut tresses as nesting material. As of last night, there were no new constellations).
One aboriginal tribe in Australia described the asterism we call Coma Berenices as a ‘small flock of birds drinking rainwater from a puddle in the crotch of a tree.’ Personally, I like that better than the royal hair story.
April Night Sky Events:
April 11: New moon.
April 14: This is the last evening to view the Zodiacal Light before moonlight interferes for two weeks.
April 22-23: The Lyrid meteor shower peaks on the night of the 22nd and morning of the 23rd. Under optimal conditions, about 20 meteors per hour can be seen. Some shower meteors are known as ‘Lyrid fireballs’ for their brightness and the lingering trains they leave in their wakes.
April 26: As the Sun sets, a full supermoon rises in the east, in the constellation Virgo. A supermoon is a full moon occurring when the Moon is closest to the Earth. It’s slightly larger than an average full moon.
April 30: See if you can find Mercury and Venus setting in the WNW during twilight.