C/2007 F1 LONEOS

Closest to Earth on Oct 28 2007 at 0.71AU
Closest to Sun on Oct 28 2007 at 0.40AU
Maximum magnitude 5 in Oct 2007
Orbital Period N/A Parabolic (Dynamically new)


C/2007 F1 LONEOS on 2007 November 5.42 UT. Visual estimate = 6.0
3 minute exposure ISO 800 with a Canon 300D digital camera + 300mm zoom lens, cropped.
The ion (gas) tail of the comet seen passing through Tau Scorpii is 5 degrees long.
Antares and globular star cluster M4 to the lower right. A satellite track is also visible crossing the image.

Discovered on 2007 March 17 by the LONEOS survey, the comet was due to have a relatively close solar encounter,
0.40AU, near the mean orbital distance of Mercury.
Being a dynamically new object with an absolute magnitude of 10, this increased its risk of disintegrating at perihelion.
 
The comet was Initially only visible from northern hemisphere latitudes
and reports in September 2007 suggested a rapid rate of brightening as it approached perihelion,
possibly achieving a maximum brightness of magnitude 4 in late October.
However the brightening rate stalled during October and comet LONEOS only reached 5th magnitude during perihelion.

The first southern hemisphere observations occurred in early November 2007
when the comet was situated very low in the south-western sky in the constellation of Scorpius.
On the evening of November 3, comet C/2007 F1 was a degree west of magnitude 7.3 globular cluster M80.
Between November 4 to 5, the comet was within 2 degrees of magnitude 5.6 globular cluster M4 near Antares.


C/2007 F1 LONEOS on 2007 November 6 at 10:30UT. FOV 2 degrees. North right. Visual estimate = 6.7
3 minute exposure ISO 800 with a Canon 300D digital camera + 300mm zoom lens, cropped.

On the evenings of November 11 to 13, the comet was situated near the naked eye double star Mu Sco,
and rich star clusters surrounding the spine of the Scorpion including NGC 6231 The Gecko


C/2007 F1 LONEOS on 2007 November 10 at 10:30UT. FOV 4 degrees. North below. Visual estimate = 7.6
The bright stars in the field are Mu1 and Mu2 Sco
 


C/2007 F1 LONEOS on 2007 November 11 at 10:30UT. FOV 6 degrees. North right. Visual estimate = 7.8


C/2007 F1 LONEOS on November 11.43 UT
3x2 minute exposure ISO 800 with a Canon 300D digital camera + 100mm zoom lens, cropped.
Note a very faint 6 degree long ion tail extending towards the lower centre of the image.
The star cluster with associated nebulosity is NGC 6231.

My observations during November indicated rapid fading of this comet, a full 2 orders of magnitude fade during the week.
This was much faster than expected, indicating that the comet suffered from significant erosion during its perihelion passage
leading to the probability that the comet had not survived.

2007 Nov 5.42 UT: m1=6.0, Dia.=3', DC=7...25x100mm Binoculars
2007 Nov 6.42 UT: m1=6.7, Dia.=3', DC=6...25x100mm Binoculars
2007 Nov 7.42 UT: m1=7.4, Dia.=3', DC=6...25x100mm Binoculars
2007 Nov 8.42 UT: m1=7.4, Dia.=3', DC=6...25x100mm Binoculars
2007 Nov 10.43 UT: m1=7.6, Dia.=3', DC=6...25x100mm Binoculars
2007 Nov 11.43 UT: m1=7.8, Dia.=3', DC=6...25x100mm Binoculars
2007 Nov 13.43 UT: m1=8.3, Dia.=2', DC=5...25x100mm Binoculars