Closest to Earth: 2005 Jan 5 at 0.34AU
Closest to Sun: 2005 Jan 24 at 1.20AU
Maximum magnitude 3.5 in Jan 2005.
On August 27, 2004, Don E. Machholz (Colfax, CA, USA) discovered his 10th comet visually with a 0.15-m reflector.
His last discovery occurred in 1994.
During October 2004, the magnitude 8 comet was well placed for southern hemisphere observers in the Eastern sky, rising about 9pm local time.
By the start of December, the comet had brightened to magnitude 6.0, trekking slowly northward through Eridanus and visible all night.
This photo was taken on the evening of December 10.
Ion tail is over 1 degree long, with the hint of dust tail to the right of the head.
3 minute exposure with Canon 300D through canon EF lens at 300mm
January 2005, comet Machholz reached a peak brightness of magnitude 3.5
and was well situated in the evening sky in the constellation of Taurus.
On the nights of January 7th and 8th, the comet was less than 3 degrees west of the Pleiades star cluster in Taurus.
2005 Jan 6
1x3 minute exposure with Canon 300D through canon EF lens at 90mm.
Note the ion tail towards the right, stretching for more than 6 degrees, whilst the dust trail above is 2 degrees long.
2005 Jan 7
9 minute exposure with Canon 300D digital camera through Canon EF 55mm zoom lens.
Pleiades star cluster is below ( note nebula surrounding Merope) and Aldebaran is the bright star at right
along with the Hyades star cluster.
Jan 7th at 12:20UT
40x10 second exposures, Starlight Express MX7c imager + C11 at f/3.3
Larsen-Sekania filter applied. Note the 2 prominent jets (6 and 7 o'clock positions) in the sunward direction.
The ion tail streamer points towards the upper right.
By the end of January, the show was over for Southern Hemisphere observers as comet Machholz trekked towards the North Celestial Pole.
Below are my visual observations in ICQ format
2004Q2 2004 09 17.67 S 10.4 TK 10 B 25 2 5
ICQ nn MAT08
2004Q2 2004 09 19.79 S 10.0 TK 10 B 25 2 4 5 m 290 ICQ nn MAT08
2004Q2 2004 10 08.73 S 8.9 TK 10 B 25 4 5 8 m 250 ICQ nn MAT08
2004Q2 2004 11 06.56 S 7.0 TK 10 B 25 7 5 ICQ nn MAT08
2004Q2 2004 11 16.59 S 6.4 TK 5 B 7 9 5 ICQ nn MAT08
2004Q2 2005 01 06.48 3.6 TK 0.7E 1 25 5 ICQ nn MAT08
2004Q2 041116.59 In 38cm reflector, dust tail 20' long in PA 265, short ion tail in PA 330. Stellar nucleus of
magnitude 11 is visible. [MAT08]
2004Q2 050106.48 Pleiades cluster used for coma measurement. In 25x100mm Binoculars, coma diameter is 22', ion tail is
>3 degrees in PA 70, dust tail >1 degree in PA 175. [MAT08]