C/2011 W3 Lovejoy
GREAT SOUTHERN CHRISTMAS COMET OF 2011

Closest to Sun: 2011 Dec 16 at 0.006AU
Closest to Earth: 2012 Jan 8 at 0.50AU
Maximum magnitude -3.

Terry Lovejoy, an Australian amateur astronomer, discovered a comet on 2011 Nov 27.7UT.
Orbital calculations indicated that it was a member of the Kreutz sungrazing group of comets.
The SOHO satellite has detected over 2000 fragments since it began operation in 1995
but this is the first ground based detection (pre perihelion) since comet Ikeya-Seki in 1965,
 and (post perihelion) since comet White-Ortiz-Bolelli in 1970.
It appeared intrinsically faint and was not expected to survive its fiery encounter with the Sun on Dec 16.02UT.
However, this sungrazing comet seemed to be in a class of its own, having experienced extreme heat at previous solar encounters.
It appeared quite spectacular in SOHO C3 images from Dec 14 at 0:00UT, and peaked at about magnitude -3 on Dec 16th.
It was stripped of its dust tail as it went through perihelion - only the head managed to survive,
but a new dust tail was seen rapidly developing as the head receded from the Sun.


2011 Dec 2.65 and 2.69UT
10x10second exposures. C11 SCT and Starlight Express MX7c CCD imager.
Motion is quite rapid and nucleus appears trailed


2011 Dec 6.72 UT
10x10second exposures. C11 SCT and Starlight Express MX7c CCD imager.
Left: Motion is quite rapid and nucleus appears trailed.
Right: stack on comet shows small circular haze with very little coma.
Visual estimate through C11 telescope at 84x = 11.2 (observation slightly affected by twilight)
This is a rare pre-perihelion visual observation of a Kreutz sungrazer!



2011 Dec 21.7UT
Canon 300D camera, 50mm lens, ASA 200. 30 second exposures.
Location: Adelaide, South Australia.
Moon is to the left of field. My first post perihelion view. The comets tail was very bright, brighter than any portion of the milky way,
and appeared 11 degrees long with the unaided eye through moderate light pollution and twilight.


2011 Dec 23.7UT
Canon 300D camera, 50mm lens, ASA 200. 20 second exposures.
Location: Goolwa, South Australia.
Unfortunately clouds interfered until start of twilight but comets bright tail could still be seen.


2011 Dec 24.7UT
Canon 300D, 50mm, asa800, 30 sec exposure.
Location: Goolwa Beach, South Australia
Once again poor conditions but I managed to capture the comet through a gap in clouds.
The tail had grown to a visual length of 20 degrees, but the brightness appeared to be have faded slightly.




2011 Dec 26.71UT
Left: Canon 300D, 18mm, iso1600, 10x30 sec exposures.
Middle: crop of photo. The pointers are above centre (Alpha/Beta Centauri), Southern Cross (Crux) is at top.
Right: 6x30 sec exposures at 50mm. Tail is to the left of the Norma Starfield.
Location: near Castlemaine, Victoria
My best observation of this spectacular comet. The tail continues to fade but is offset by its increasing length as it approaches Earth.
This morning the tail is seen visually for 30 degrees, extending to Beta Centauri, with the first 10 degrees particularly bright
This photo shows a fainter extension out to 40 degrees.
Note the Emu (Aboriginal sky constellation) , the dark nebulosity running through the milky way is the neck
The head and beak are at top, better known as the Coalsack nebula.


2011 Dec 27.71 and Dec 28.71
Canon 300D, 18mm, iso1600, 10x30 sec exposures. Cropped.
Location: backyard in Castlemaine, Victoria. Slight interference with local light pollution.


2011 Dec 30.71UT
Left: Canon 300D, 18mm, iso1600, 14x30 sec exposures. Cropped. Eta Carinae nebula is at top.
Right: at 50mm, 8x30 second exposures.
This image was taken from a dark site near Castlemaine.
The visual tail length with the unaided eye has reduced to 17 degrees and photographically about 25 degrees.
The bright milky way is interfering with the view.
The tail is continuing to fade with each passing morning and is now of similar surface brightness to the SMC.
Thus no longer likely to be observable from light polluted city skies.


2011 Dec 31.54UT A new Years Comet.
Left: Canon 300D, 18mm, iso1600, 6x30 sec exposures. Cropped.
Right: with added fireworks display. Comets tail can be seen faintly above the tree.
Location: Castlemaine, Victoria.


2012 Jan 04.69UT
Canon 300D, 18mm, iso1600, 12x30 sec exposures. Cropped. Southern cross is left of centre.
Location: near Castlemaine, Victoria.
Approximately 10 degrees of tail was observed with the unaided eye using averted vision, extending just beyond Alpha Apus.
The intensity has dropped off substantially since my last observation on Dec 30.71, and is now a very difficult naked eye target.
Through 8x40mm Binoculars, the tail extends through to Beta Chameleonis for a total of 20 degrees.
Photographically the tail length is about 30 degrees, passing near Beta Carinae.
Interestingly the brightest section of tail now appears to be at the head of the comet.
I estimate this to be about magnitude 6.5
 


2012 Jan 15.50UT
Canon 300D, 90mm, iso800, 4x3min stacked exposure. Cropped.
Location: Castlemaine, Victoria.
Comet is now virtually undetectable through 8x40mm binoculars and is fainter than the LMC.
Left: Photographically, a faint tail is seen about 3 degrees in length, skirting the edge of the LMC.
Right: The tail extends to Beta Doradii with image processing for a total of 9 degrees.