A comet first seen by a German amateur astronomer in July, then lost for five days, is now an easy target for small telescopes in the Northern Hemisphere. This unexpectedly bright comet (magnitude 7.5 or so) is currently moving through Draco, heading toward Ursa Major and Canes Venatici.
It was shortly after midnight on July 22nd that Sebastian Hoenig of Dossenheim, Germany, found himself unable to sleep. So he got up, loaded his Meade 10-inch telescope into the car, and drove to his favorite observing site in the Odenwald woods near Heidelberg. He soon stumbled upon a fuzzy glow just north of the Great Square of Pegasus, in a region he knew to be almost devoid of galaxies and other deep-sky objects. But Hoenig had no star atlas with him — not even a scrap of paper for making notes — so he rummaged through the car and turned up an empty water bottle! Its small white label was just large enough for him to make a careful sketch of the star field. He kept the object in view long enough to determine that it was moving slowly to the north, at about 3 arcminutes per hour.
Later that day Hoenig e-mailed the discovery details to the Central Bureau of Astronomical Telegrams (CBAT) in Cambridge, Massachusetts. But neither he nor any other observer could locate the object again, owing to a very bright Moon and the object's uncertain location. Finally on July 27th, Ken-ichi Kadota in Saitama, Japan, captured a CCD image of the comet 8° north of Hoenig's initial position, thus confirming the discovery. With this find, Sebastian Hoenig becomes the first amateur astronomer to discover a comet from German soil since 1946.
But he's no stranger to comets; he is also credited with locating 20 comets in SOHO spacecraft images of the Sun's vicinity.
Calculations by Brian G. Marsden(Smithsonian Astrophysical Observatory), announced August 6th, indicate that Comet Hoenig will reach perihelion (its closest point to the Sun) around October 2nd. It'll then be situated between the orbits of Venus and the Earth, traveling in a near-parabolic orbit inclined 73° to the plane of the ecliptic.
The ephemeris below gives the comet's right ascension and declination (equinox 2000.0) at 0 hours Universal Time, its predicted magnitude, and the constellation though which it's passing.
|Comet Hoenig (C/2002 O4)|
|Sep 15||12 51.9||+48 56||8.4||CVn|
|Sep 17||12 48.8||+47 07||8.4||CVn|
|Sep 19||12 45.9||+45 21||8.4||CVn|
|Sep 21||12 43.4||+43 38||8.4||CVn|
|Sep 23||12 41.0||+41 58||8.4||CVn|
|Sep 25||12 38.7||+40 20||8.4||CVn|
|Sep 27||12 36.7||+38 43||8.4||CVn|
|Sep 27||12 34.7||+37 09||8.4||CVn|
|Oct 1||12 32.9||+35 35||8.5||CVn|
|Oct 3||12 31.3||+34 03||8.5||CVn|
|Oct 5||12 29.7||+32 31||8.6||CVn|