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A. More. Comet. Although the next big "Comet of the Century" has not yet appeared in 2018, we have had a steady stream of binocular comets this year, including the Comets C / 2017 S3 PanSTARRS, the 38P Stephan-Oterma and the 21P Giacobini-Zinner. .
The calendar year may have kept the best for the end, while the periodic comet 46P Wirtanen occupies a central place.
The astronomer Carl Wirtanen observed for the first time the 46 e periodic comet listed in the catalog the night of 17 to 1948, while there performed a stellar survey of the movement from the Lick Observatory. Wirtanen then discovered four other comets.
Although it took more than a year to build the orbit of the comet, we quickly realized that its orbital period was really short: it only took 5 , 4 years in Wirtanen to turn around the Sun. an aphelion of 5.1 astronomical units (AU) inside Jupiter's orbit in a perihelion of 1.06 AU, just outside the Earth's path around the Sun. The orbit of the comet is also 11.7 degrees inclined to the ecliptic. The orbit of the comet 46P Wirtanen has been slightly modified by successive pbadages near Jupiter in 1972 and 1984.
Trivia: The comet 46P Wirtanen was formerly on the list of potential destinations of the Rosetta mission of the 39, European Space Agency, which was then to go to Comet. 67P Churyumov-Gerasimenko.
201P Pbad from Wirtanen, in 2018, is the closest to Earth since it was discovered 70 years ago, and the closest to 21 century. In fact, we are at 20 e best-known cometary pbadage near the Earth … period. But as we will show you in a few moments, this close approach is conducive to observation … with some caveats.
In 2018, comet 46P Wirtanen begins the month of November with a respectable magnitude of the 8th, ascending the southern hemisphere sky from the constellation of Fornax the furnace to the cetus whale . The action heats up in December as the comet picks up speed and moves 4 degrees a day (the equivalent of the diameter of a full moon every three hours!) Approaching closer in mid-December, crossing the constellations of Eridan, Taurus and Auriga as it rises above the plane of the ecliptic and in the northern hemisphere sky. From 30 degrees north latitude, comet 46P Wirtanen is just south just before midnight in December. It begins the month at 40 degrees above the horizon, crosses the midnight zenith on December 18th and rings for the New Year 2019 60 degrees above the northern horizon north at 2 o'clock local.
Not bad to observe. A global campaign is underway to observe the Comet 46P when it first appeared in 2018, including that of the University of Maryland.
Here are some key observation dates for Comet 46P Wirtanen:
] November
1-Breaks +10 th magnitude.
18-Pbades near (unless otherwise indicated, we designate as "close pbades" for this ephemeris Nu Fornacis
Star of magnitude 5 of magnitude 27 – Pbadage in the constellation Cetus.
December
5-Cross in the constellation of Eridanus
6- Pbad near the star of magnitude 3.8 Azha.
9-Cross in the constellation Cetus.
10-Crosses the celestial equator to the north.
12-Traverse to the constellation Astronomical Taurus.
13-Reaches the peribelion at 1,048 AU from the Sun
15-Crosses the ecliptic plane to the north.
16-Photo-op: pbades two degrees from the open cluster Pleiades (M45)
16 pbadages closest to the Earth, at a distance of 0.077 AU (7.16 million miles). 9659002] 19- Traverse in Perseus.
21-Traverse Auriga.
22-Crosses the galactic plane to the north.
22-Pbad near the brilliant star Capella.
28-Crosses the Lynx.
January
10-Reaches a maximum incline north of +59 degrees.
12-Pbadages in Oursa Major.
February
11 pbades near the star of magnitude +3, Theta Ursa Majoris. Its near pbadage (7.16 million miles) just 29 times farther than the Moon bodes well for a maximum magnitude of +3: possibly to the naked eye. However, keep in mind that all this brightness will be stifled by an extended coma, another consequence of its close approach. Make sure to look for dark skies in your quest for Comet 46P Wirtanen in 2018.
Good luck and clear sky!
Read all about comet observation in our new book, Ideal Guide to Visualize the Universe Cosmos: On Sale Now
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