Comets have been the most unpredictable celestial travellers. They suddenly appear out of nowhere and then disappear. One such apparition of the skies is the recent discovery, comet Howell. A tailless comet, it shows up in the twilight hour, is the brightest in the sky and travels through the eastern skies. Comet Howell is visible only in the southern hemisphere. It is a short–period comet that belongs to the Jupiter family. Let us explore this comet in detail.
Student–astronomer Ellen Howell from the California Institute of Technology, California USA was the first to discover this comet. She discovered this comet on photographic plates obtained with the help of a 0.46 m Schmidt at the Palomar Observatory This discovery of 29th August, 1981 was confirmed by Howell on 30th August, 1981. The comet was located within the constellation of Cetus.
Observations made about comet 88P/Howell include:
- The comet appeared diffused and tailless.
- Well–known astronomer B G Marsden computed two orbits for this comet, parabolic and elliptical. Finally, an elliptical orbit was confirmed by him.
- The coma was between 3–5 arc minutes when it had steadily brightened by October–November 1998.
On its discovery in 1981, the magnitude of the comet 88P/Howell was revealed at 15. On its 1987 apparition, the comet reached its brightness at magnitude 12. The comet reached a declination of –7 0 and by the end of February 1998 and by October–November, it brightened with a magnitude of about 10.5.
Perihelion (closest to the sun) distance of comet 88P/ Howell is 1.40 AU while its aphelion (farthest from the sun) distance is 4.87 AU.
The orbital period of comet Howell was computed at 5.94 years. Also, its orbit is elliptical and has an angular inclination of about 4.30.
Comet Howell had a close approach to Jupiter in the year 1990, which decreased its perihelion distance. The comet also had a close approach to Earth in May 1998.
The comet had closely approached the earth during May, 1998. Perihelion of comet 88P/Howell is in year 2020. It had last appeared on 12th October, 2009 and 6th April, 2015. The comet appears every 5.5 years and is expected to appear in 2020.
