Astronomy January 2022

When in 1774 the French comet hunter Charles Messier began listing fuzzy patches of light in the sky, wanting to separate them from the comets that interested him, he started quite a trend. His list of Messier objects — originally 45 targets, eventually expanded to 109 — constitutes the most famous of the checklists that provide backyard astronomers with a rounded survey of celestial delights. But Messier’s list is hardly the only such compilation. For instance, dedicated deep-sky observers know the New General Catalogue, assembled by J.L.E. Dreyer in 1888 and expanding on work done by the Herschels. It contains a whopping 7,840 galaxies, clusters, and nebulae, and two additions, the Index Catalogues, add another 5,386 objects. These lists, coupled with a dark sky and a moderate-sized telescope, offer literally a…

1 Centaurus A Centaurus A (NGC 5128) is a standout object for Southern Hemisphere observers. NGC 5128 is often called the Hamburger Galaxy because of the two regions of stars (the bun) that surround a dark dusty lane (the burger). And it’s a heck of a meal: A mere 12 million light-years away, Centaurus A has a diameter of about 60,000 light-years. Scottish astronomer James Dunlop discovered NGC 5128 in 1826 using a 9-inch reflecting telescope in his observatory in Parramatta, New South Wales, Australia. Astronomers gave it the catalog name Centaurus A because it was the first radio source discovered in the constellation. Both NGC 5128’s appearance and its radio emission have their roots in a galactic collision. The main body of Centaurus A — a giant elliptical galaxy — is absorbing…

Visible to the naked eye Visible with binoculars Visible with a telescope The new year opens with a spectacular array of planets lined up in the western sky soon after sunset. Mercury, Venus, Jupiter, and Saturn offer nightly fascination. A crescent Moon skips along this line of planets over a few nights early in the month. The inner pair of planets, Mercury and Venus, swaps places in the first week of January. Mercury remains in view through midmonth, while Jupiter and Saturn are visible all month. Uranus and Neptune can be spotted with binoculars, riding high in the southern sky after sunset. Only Mars is missing from the nightly lineup — it’s over in the morning sky, transiting the rich star clouds of the Milky Way. Four major planets crowd the evening twilight sky…

THERE’S NO HIDING the crater Kepler! The youthful impact scar stands out on the Moon’s equator, a veritable island in Oceanus Procellarum, the large basin on the eastern flank of our satellite. Kepler is a smaller version of the prominent Copernicus, which lies closer to the Moon’s center. Kepler is a round, sharply defined deep bowl. On the 13th, the low Sun angle highlights the rough skirt of debris that spread out during the impact event that created it. A bit to the south lies Encke, similar in size to Kepler, but its older, bombarded rims are softer and, more importantly, it is filled with Kepler’s rubble. Return in the next couple of evenings to see how a higher Sun angle transforms the roughness and shadows into a bright apron with rays.…

Quadrantid meteor shower THE QUADRANTIDS, which originate in what is now the northern region of Boötes, are active between Dec. 28 and Jan. 12. The narrow peak of activity (six hours, according to the International Meteor Organization) occurs Jan. 3. With the Moon near New, if the weather cooperates, the chances are good for a fine view. The predawn hours are always the best time to view meteor showers, and the Quadrantids are no exception. The radiant rises late in the evening and by 4 A.M. local time, it’s about 40° high. Expect about 25 to 30 meteors per hour if the peak occurs during the dark window of your observing site, corresponding to a zenithal hourly rate of 100 to 120. Look also for the occasional fireball known to occur…

HOW TO USE THIS MAP This map portrays the sky as seen near 35° north latitude. Located inside the border are the cardinal directions and their intermediate points. To find stars, hold the map overhead and orient it so one of the labels matches the direction you’re facing. The stars above the map’s horizon now match what’s in the sky. The all-sky map shows how the sky looks at: 9 P.M. January 1 8 P.M. January 15 7 P.M. January 31 Planets are shown at midmonth MAP SYMBOLS STAR MAGNITUDES STAR COLORS A star’s color depends on its surface temperature. • The hottest stars shine blue• Slightly cooler stars appear white• Intermediate stars (like the Sun) glow yellow• Lower-temperature stars appear orange• The coolest stars glow red• Fainter stars can’t excite our eyes’ color receptors, so they appear white unless you…