This month, a periodically returning comet designated 21P/Giacobini-Zinner will be bright enough to be seen in binoculars and small telescopes. It is expected to continue to brighten until the morning of Sept. 10, when it will pass within 36.3 million miles (58.5 million kilometers) of Earth on its way around the sun.
Sometimes, if its orbit is just right, a comet will appear to pass close to major stars in the sky, which makes it easier for non-experts to find the object. And, even better, comets occasionally pass close to the positions in the sky of distant deep-sky objects. This sets up spectacular telescope views and wide-field photo opportunities for tripod-mounted cameras or close-up views using DSLR cameras affixed to tracking telescopes.
Lucky for us, Comet 21P’s path will take it along the Milky Way, setting up a series of spectacular close encounters during September and October. And many of the best ones will occur when the moon is not very bright, as is the case this week.
Sept. 8 after midnight EDT (after 0500 GMT) — The comet will pass 2.5 degrees west (left) of two bright open star clusters in Auriga designated Messier 38 and Messier 36 (use binoculars).
Sept. 9 to 10 — On these nights, the comet will pass between the bright stars Mahasim (Theta Aurigae) and Elnath (Beta Aurigae) while heading south (downward). The object will be somewhat closer to Mahasim, the dimmer, left-hand star (use binoculars).
Sept. 10 — On Sept. 10, the comet will reach its closest point to both the sun and to Earth. Around this date, we expect the object to peak in visual brightness: around magnitude 7.0.
Sept. 10 to 11 — On these nights, the comet will glide past the open star cluster designated Messier 37, passing only 10 arc minutes (or one-third of the full moon’s diameter) from the cluster at 1900 GMT on Sept. 10. Observers in Asia and Oceania will see the objects close together. Most of the Western Hemisphere will have to settle for seeing the comet 1 degree from the cluster on each night (best viewed in a telescope).
Sept. 15 — At about 6 a.m. in the Eastern time zone (1000 GMT), the comet will glide directly through the open star cluster designated Messier 35 (use a telescope).
Sept. 16 — During the night, the comet will approach the bright star Propus (Eta Geminorum), passing within 0.5 degrees west (to the upper right) of the star just before dawn. The Jellyfish Nebula (IC 443) will be within a telescope’s field of view at low magnification. Closest approach to Propus will occur at around 1500 GMT. And the event is visible only for skywatchers in Asia and Oceania (use binoculars or a telescope).
Sept. 17 — In the early hours of Sept. 17, the comet will be positioned below Propus and approximately midway between the bright star Tejat (Mu Geminorum) and NGC 2174, also known as the Monkey Head Nebula. The comet and the nebula will appear together in the field of view of a low-magnification telescope.
Sept. 23 — The comet will begin to move across the plane of our galaxy. During this night, the comet will pass near a collection of dim deep-sky objects in northern Monoceros, including the star clusters and nebulas designated NGC 2247, NGC 2245, IC 2167, IC 2169 and NGC 2259 (use a telescope). Note: The nearly full moon will wash out the sky somewhat for this encounter.
Sept. 24 — On this night, the comet will pass about 1 degree east (to the right) of NGC 2264, also known as the Christmas Tree Cluster. Both objects will fit in the field of view of a telescope. On the next night, the nebula will still be less than 2 degrees from the comet. Note: The full moon will wash out the sky somewhat for this encounter.
Sept. 26 — Look for the comet sitting 3 degrees northeast (to the left) of the spectacular star cluster and nebula combination known as the Rosette Nebula (NGC 2244) in Monoceros. This pairing will make an excellent wide-field photo opportunity and sight in binoculars. Note, the waning full moon will wash out the sky somewhat for this encounter.
Oct. 7 to 8 — On these dates, it will glide past the open star cluster designated Messier 50 in southern Monoceros. Closest approach, with the comet skimming the cluster’s outskirts, will occur at 1900 GMT on Sept. 7 — an event visible only to Asia and Oceania. North American observers will see the comet positioned about 0.5 degrees from the cluster on those two mornings. (Use binoculars or a telescope.)
Oct. 9 to 10 — On these two mornings in the predawn hours, the comet will move past the bright Seagull Nebula (IC 2177) and then descend through the large and faint reflection nebula designated IC 2327. Other nearby objects will include the star clusters NGC 2335 and NGC 2343. This will be another wide-field photo opportunity, as well as a sight visible via binoculars and telescope.
Video Courtesy – ” Riccardo Furgoni “
News Courtesy – ” Space.com “
Akshat Mishra is a Physics Undergraduate at Centre for Excellence in Basic Sciences, Mumbai. He feels the need to explore the depths of the not-so-dark universe while at the same time watch the quanta in action. Electronic Music is what puts him in the thinking zone.