Originally detected independently by Rob Matson (USA) and Michael
Mattiazzo (Australia) from SOHO/SWAN satellite images in late June
2006, details were circulated to selected observers in the southern
hemisphere to try and confirm the new comet, even though it was
close to the Sun in the sky and difficult to observe. The comet was announced officially
on 12 July 2006 in IAUC
8729 (subscription
required).
Terry Lovejoy found he had images of the new comet from wide field
survey images he had taken on 30 June 2006 with a digital camera and
100mm focal length lens, noting the comet as about ½° diameter
while Rob McNaught using the 0.5-m Uppsala Schmidt telescope on July 12
noted a concentrated coma and a short tail less than 1½' long.
The comet was on its way into perihelion at that time, with
closest approach to the Sun due on 28 Sep 2006 at a distance of 0.78
AU. However, the elongation of the comet steadily decreased as well
and indeed it passed almost exactly behind the Sun.
Unfortunately, this time coincided with a "SOHO
Keyhole" (when little or no data is obtained from the
spacecraft) and together with the comet being predicted to be as
faint as 9th magnitude at that time, being twice as far away from us
as the Sun during its passage through the field of view, nothing
was seen of the comet.
With astrometry reported for the comet from 16-27 July 2006 from
the southern hemisphere, it was next reported from the Ageo
Observatory in Japan as early as 18 September 2006 (after conjunction
with the Sun) at 8th magnitude and at
a solar elongation of only 25°. Over the next few weeks it
gradually pulled away from the Sun and moved into the evening sky,
reaching its closest to Earth at the end of Oct 2006 but still 1 AU
away. Maximum elongation of 62° from the Sun will be achieved by
mid-November 2006 but the comet will then close in to another
conjunction with the Sun in Feb 2007. By the time the comet
reappears out of the solar glow in April/May 2007 it will be well
over 3 AU from both Sun and Earth and likely to be very faint.
|