MAY 2020 OBSERVING Celestial Calendar by Bob King Comet T2 Hits the Big Time What might prove to be the year's finest comet is at its best in May. G rab our chart and click on your red flashlight. You'll want to spend a few nights with Comet PanSTARRS (C/2017 T2) this month. Now at its brightest, the comet was discovered by the Panoramic Survey Telescope and Rapid Response System (PanSTARRS) in May 2017, when the object was well beyond the orbit of Saturn. Three years later, it finally reaches perihelion on May 4th, at distance of 1.6 a.u. (242 million kilometers) from the Sun. Amateurs have been watching T2 slowly blossom from the 14th-magnitude midge it was more than a year ago into a binocular target. The comet should reach and sustain at least 8th magnitude through May and into June as it ambles southeast from Camelopardalis to Ursa Major. 18h 19h 20h 22h 0h 2h With a minimum declination of +66°, the comet will be circumpolar and visible all night, even from the southern United States. As May begins, Comet T2 will be traveling toward the Big Dipper at around 40 arcminutes per day, increasing to 50 arcminutes after mid-month. The chart below shows notable celestial pairings on its route that include the 3h Apr 18 α DRACO γ Polaris α 22 η γ May 4 β C/ 20 17 T2 8 Pa th of α λ 28 M101 CAMELOPARDALIS 2 3 4 5 6 7 12 16 Co m et URSA MINOR Star magnitudes 26 30 20 0 24 M82 M81 +50° June 1 Mizar η M51 5 ε ζ M40 CANES VENATICI M109 γ LYNX β 13 M63 M97 M108 URSA MAJOR 13h 48 α 9 Big δ Dipper M106 M AY 2 0 2 0 * S K Y & T E L E S C O P E 12 h 11 h 10h 9h +40°