C/2014 Q1 PANSTARRS
Closest to Sun on 6 July 2015 at 0.31AU
Closest to Earth on 20 July 2015 at 1.18AU
Maximum magnitude 4 in July 2015
With a perihelion distance of 0.31AU on 2015 July 6, this
comet had the potential to reach magnitude 4.
Unfortunately at this time, it was at very low solar elongation. C/2014 Q1 is a long period object, with an orbital period of about 38,000 years.
The comet has been baked by the Sun on previous encounters so prospects for surviving another Sun approach were good.
I managed to follow this comets development during 2015 April and May, post Solar conjunction, when the solar elongation was a mere 22-25 degrees and the
comets altitude a mere 5 degrees. Very few worldwide observations of this comet were being reported since the observing circumstances were quite poor,
slightly favouring southerners. Such is the advantage of the amateur observer that can reach low altitudes.
My photometric estimates were magnitude 12.5 on April 30, 11.5 on May 16 and 10.7 on May 26.
C/2014 Q1 PANSTARRS.
2015 April 30 at 19:40UT.
Post Solar conjunction. Photometric magnitude =12.5.
Solar Elongation was only 22 degrees and altitude 4 degrees!
C/2014 Q1 PANSTARRS on 2015 May 16 at 19:58UT.
Celestron C11 + Starlight express CCD image. 5 minute stack
Above: C/2014 Q1 PANSTARRS taken on 2015 May 26.
These estimates indicated that the comet was running a full magnitude behind prediction.
The comet arrived at perihelion on 2015 July 6 at about the same distance as Mercury to the Sun (0.3AU).
The elongation from the Sun was only 10 degrees at the time, yet Michael Jager in Austria was able to image it at magnitude 4.
A record observation for a 4th magnitude comet. The comet must have had a small outburst at perihelion to reach this peak.
By mid-July, the comet moved sufficiently far enough away from the Sun to be visible, low in the western evening sky in Cancer.
I managed several visual and photographic observations of the comet. It was an impressive object despite the difficult viewing circumstances.
On the evening of July 15, I estimated magnitude 5.0 through 25x100mm
The nucleus displayed a bright parabolic hood indicating a recent outburst. Photographically the comet showed 3 separate tails
On 2015 July 19 at 08:50UT the comet was barely detectable with the naked eye due to moonlight
but the view through 25x100mm binoculars showed a 2 degree long ion tail superimposed on a 1 degree dust tail in PA 104 and a 1 degree long dust "trail" in PA 23. Photographically, the ion tail was traced to 7 degrees.
On July 23, the fading comet appeared magnitude 5.9 through 8x40mm binoculars.
below image from July 23 showing twin dust tails accompanied by a thin ion tail winding through to top of image
below image taken on July 24
C/2014 Q1 PANSTARRS visible in evening
skies but fading. Below image taken on July 26
On Aug 2nd, the ion tail had faded considerably, but two well defined dust tails
separated by an angle of 90 degrees were visible.
There was a type II dust tail pointing Eastwards, made from fine dust blown away by solar radiation pressure,
and a type III dust "trail" pointing Northwards, made by coarse dust trailing behind the comets nucleus.
Comet PANSTARRS displays a sunward pointing "anti-tail" nearly 1 degree long in this image taken on 2015 September 4.
The type III tail gradually orientated sunwards and became an "antitail" on October 2, when the Earth crossed the comets orbital plane.
During August, the comet faded from magnitude 7.5 to 10.0 as it receded from Earth and Sun.
On August 1, the magnitude 7 comet was situated in Sextans, low in the evening sky at about 19 degrees altitude at 7pm local time.
However, moonlight interfered until the night of the 2nd.
The comet trekked slowly south-eastwards and crossed into Crater on the 5th.
On the 11th, it was 1.5 degrees west of Lambda Crt.
By the time it entered Hydra on the 18th, it had faded to magnitude 9 and moonlight once again interfered.
On the 23rd, the comet was 30' to the west of a magnitude 11 elliptical galaxy NGC 4105.
At the end of August, the magnitude 10 comet wa situated in Centaurus.