2. • C/2014 Q2 (Lovejoy) is a new discovery -
August 18, 2014 by Terry Lovejoy
(Brisbane), his 5th.
• At the time in Puppis was “shining” at
15th magnitude.
• As of January 2nd it was being reported
at about magnitude 4.7 to 5.2, but the
light of the waxing gibbous Moon filling
the sky has made it a lot harder to see.
3. Comet Lovejoy features.
• This is a very LONG-PERIOD** comet (orbital
period of +/- 11 500 years).
• Due to perturbations by the planets – shortened
to about 8000 yrs.
• ** Orbital periods depend on origin of the
comet:
– Long period comets (> 200 yrs) originate from the
Oordt Cloud (can be thousands to millions of years),
– Short period comets ( < 200 yrs) are from the Kuiper
Belt (Two families: Jupiter family < 20 yrs, Halley
family: 20 – 200 yrs).
4. • The green colour : Usual for comets’ heads – Molecules of
diatomic carbon (C2) fluorescing in the Sun’s UV light,
• Also some violet (to which our eyes are insensitive) – from
cyanogen (CN),
• The gas tail (ion tail):
– Points away from the sun,
– Tinted blue: Carbon Monoxide ions fluorescing,
– NOT visible in these images - taken from a LIGHT POLLUTED site.
• Dust: appears Sun-coloured: reflected sunlight,
• (Lovejoy had LITTLE dust…),
• “Great” comets usually thus very dusty/ visible, like Lovejoy
of 2011; Hale-Bopp of 1997 etc.
Comet Lovejoy features.
5. “Angular Displacement/ Distance
travelled” in +/- 50 minutes.
• The next slides demonstrate the movement of the
comet against background stars over a period of
50 minutes.
• Jan 2nd, 2015: Two images taken at 21h10 and
21h59: Comet Lovejoy was travelling at +/- 36
km/ sec** relative to the Sun,
• **On Jan 6th : 36.38 km/s (speeding up); +/- 200
mill. km from the Sun, +/- 70 mill. km from Earth.
• The field of view** is +/-0.66 deg. (Horizontal) –
see next slide.