This Week in the Sky-January 15-21, 2023
January 15, 2023
The Spectacular Orion Nebula (all night) The sword of Orion, which descends from his three-starred belt, contains the spectacular and bright Messier 42 (aka the Orion Nebula). Even binoculars will reveal the fuzzy nature of this central object in the hunter’s sword that covers an area of 1.5 by 1 degrees. Messier 43, a section of the same nebula which lies just to the north of M42, has been separated from the main gas cloud by dark foreground dust. Medium-to-large aperture telescopes will reveal a complex pattern of veil-like gas and dark dust lanes in M42 and M43. O-III or broadband nebula filters will reveal more details. The nebula and the stars forming within it are approximately 1,350 light-years from the sun and about 24 light-years across.
January 16, 2023
The Pleiades (all night) At about 8 p.m. local time on mid-January evenings, the Pleiades open star cluster, also known as the Seven Sisters and Messier 45 is positioned high in the southern sky. The rest of its home constellation Taurus, the Bull will be situated below the cluster. Visually, the Pleiades are composed of medium-bright, hot blue stars named Asterope, Merope, Electra, Maia, Taygeta, Celaeno, and Alcyone. In Greek mythology, those characters were the daughters of Atlas, and half sisters of the Hyades. They are indeed related – born of the same primordial gas cloud. To the naked eye, only six of the sister stars are usually apparent; their parents Atlas and Pleione are huddled together at the east end of the grouping. In binoculars and backyard telescopes, hundreds of stars appear. Not surprisingly, many cultures, including Aztec, Maori, Sioux, Hindu, and more, have noted this object and developed stories around it. In Japan, it is called Subaru, and forms the logo of the eponymous car maker. Due to its shape, the cluster is sometimes confused with the Little Dipper.
January 17, 2023
The Top of Orion’s Sword (all night) Orion’s position within the plane of the Milky Way has populated it with numerous nebulas and star-forming regions. The sword of Orion, which descends from his three-starred belt, contains a chain of worthy targets in addition to the famous Orion Nebula (Messier 42). The top of the sword consists of the scattered stars of NGC 1981. A telescope will reveal about forty 6th to 9th magnitude stars in a 0.5 degree field. The next object, called The Running Man Nebula (Sh2-279), is one the sky’s brightest reflection nebulas – composed of blue gas, darker dust, and stars in a package spanning 42 by 26 arc-minutes across. The medium-bright stars 42 and 45 Orionis sit mostly to the south of the gas components NGC 1973, NGC 1975, and NGC 1977.
January 18, 2023
Crescent Moon near Antares (pre-dawn) After the waning crescent moon rises in the southeastern pre-dawn sky on Wednesday morning, January 18, it will be accompanied by the bright, reddish star Antares, the heart of Scorpius, twinkling just 1.5 degrees to its southwest. The pair will be close enough to share the view in binoculars until the brightening sky hides Antares. Watch for Mercury shining off to their east (lower left).
January 19, 2023
Nebulas near Orion’s Belt (evening) In late January, mighty Orion stands over the southern horizon, crossing into the western half of the sky at about 9:30 p.m. local time. A number of interesting targets are located in the region around Orion’s famous three-starred belt. Alnitak’s radiation causes the hydrogen in the large, but faint Horsehead Nebula (IC 434), located half a degree south of the star, to emit red light from beyond distinctively silhouetted dust. Use a large aperture telescope or a long exposure image. The Flame Nebula (NGC 2024) is a half-degree wide emission and reflection nebula located just 0.25 degrees to the east of Alnitak. Several nearby 7th-magnitude stars sport blue reflection nebulosity.
January 20, 2023
Jupiter at Perihelion (all day) On Friday, January 20, the giant planet Jupiter will reach perihelion, its minimum distance from the sun for its current orbit. Today Jupiter will be 460.224 million miles, 740.659 million km, or 4.95 times the mean Earth-sun distance. From here on Earth Jupiter won’t look any larger or brighter tonight, but at Jupiter’s next six oppositions the planet will show a diminishing disk size in telescopes. Jupiter will grow in size during the years preceding the next perihelion on December 5, 2034, but it won’t be this close to the sun again until the late 2050’s.
January 21, 2023
New Moon The moon will reach its new phase on Saturday, January 21 at 3:53 p.m. EST, 12:53 p.m. PST, or 20:53 UT. At that time our natural satellite will be located in southwestern Capricornus, 5.5 degrees south of the sun. This new moon will occur while the moon is at perigee, its closest approach to Earth, producing high tides worldwide. While new, the moon is travelling between Earth and the sun. Since sunlight can only reach the far side of the moon, and the moon is in the same region of the sky as the sun, the moon becomes unobservable from anywhere on Earth for about a day (except during a solar eclipse). On the evenings following the new moon phase, Earth’s planetary partner will return to shine in the western sky after sunset.
The information presented here is taken from my personal copy of Starry Night 8 Pro Plus, all rights belong to Starry Night Education/Simulation Curriculum.