The sky this week from January 7 to 14
Monday January 10
Morning watchers before the sun can enjoy a full view of Hydra the Water Serpent this morning. Covering approximately 1,303 square degrees, it is the largest of the 88 officially recognized constellations in our skies. It might seem intimidating to watch, so let’s just zoom in on its head, which covers a smaller, more maneuverable 20 °.
The head of the water serpent can be found next to Cancer the Crab and about 15.5 ° east of Luminous Procyon in Canis Minor. The head itself is represented by the stars Zeta (ζ), Epsilon (ϵ), Delta (δ), Sigma (σ) and Eta (η) Hydrae. First, focus on Epsilon with your telescope – it is not a single luminaire but actually a double star, also cataloged as Struve (STF) 1273. Its components are from magnitude 3.5 and 6.7, and are only 2.9 inches apart. You will need stable vision and a scope of about 5 inches to separate them. Can you do it ?
If you want an easier to observe double, slide to Delta, then look 1 ° north to spot STF 1245. These are both fainter at magnitudes 6.0 and 7.2, but separated by a wider 10 , 1 “. Their different spectral classes – F8 and G5 – mean that close attention can reveal different colors.
Several other double stars are found in or near the head of Hydra, including STF 1255 and STF 1290. The first is easy to split, but the second is more difficult than Epsilon.
Sunset: 4:54 p.m.
Moon setting: 00:45
Moon phase: Gibbous shoe polish (60%)
Tuesday January 11
The Moon passes 1.5 ° south of Uranus at 6 a.m. EST. As the sun sets tonight, they are at a respectable height of 5.7 ° apart in the southern sky, making it easy to perceive the dim light of Uranus after dark.
To locate the distant ice giant, which now sits southwest of the Moon, look for Hamal of magnitude 2, Ram’s brightest star. Drop 10.7 ° in the lower left (southeast) to spot the 5.8 magnitude Uranus glow through binoculars or a telescope. The planet’s disk spans nearly 4 “and should appear as a” flat “, greenish-blue star. Uranus is currently located about 19.4 astronomical units (AU) from Earth, where 1 AU is the distance. Earth-Sun average This means that the sunlight reflected off its surface must pass through the solar system for almost 3 hours to reach our eyes.
Asteroid 3 Juno is in conjunction with the Sun at 5 p.m. EST tonight.
Sunset: 4:55 p.m.
Moon setting: 01:46
Moon phase: Gibbous shoe polish (69%)