C/2007 W1 (Boattini)


C/2007 W1 (Boattini)
Discovered byAndrea Boattini
Mt. Lemmon Survey (G96)[1]
Discovery date20 November 2007
Orbital characteristics A
Epoch28 May 2008
(JD 2454614.5)
Aphelion~3,163 AU[2] (Q)
Perihelion0.84972 AU (q)
Semi-major axis~1,582 AU[2] (a)
Orbital period~63,000 yr[2][4]
Earth MOID0.0178 AU (2,660,000 km)
Last perihelion2008-Jun-24[3]
Next perihelionunknown

C/2007 W1 (Boattini) is a long-period comet discovered on 20 November 2007, by Andrea Boattini at the Mt. Lemmon Survey.[1] At the peak the comet had an apparent magnitude around 5.[5]

On 3 April 2008, when C/2007 W1 was 0.66AU from the Earth and 1.7AU from the Sun, the coma (expanding tenuous dust atmosphere) of the comet was estimated to be as large as 10 arcminutes.[6] This made the coma roughly 290,000 km in diameter.[7]

On 12 June 2008, the comet passed within about 0.21005 AU (31,423,000 km; 19,525,000 mi) of the Earth.[8] The comet came to perihelion (closest approach to the Sun) on 24 June 2008 at a distance of 0.8497 AU.[3]

The comet has an observation arc of 285 days[3] allowing a good estimate of the orbit. The orbit of a long-period comet is properly obtained when the osculating orbit is computed at an epoch after leaving the planetary region and is calculated with respect to the center of mass of the solar system. Using JPL Horizons, the barycentric orbital elements for epoch 2020-Jan-01 generate a semi-major axis of 1,582 AU, an apoapsis distance of 3,163 AU, and a period of approximately 63,000 years.[2][4]

Before entering the planetary region, C/2007 W1 had a hyperbolic trajectory.[2] The comet was probably in the outer Oort cloud with a loosely bound chaotic orbit that was easily perturbed by passing stars.


  1. ^ a b "MPEC 2007-W63 : COMET C/2007 W1 (BOATTINI)". IAU Minor Planet Center. 23 November 2007. Retrieved 13 April 2011.
  2. ^ a b c d e Horizons output. "Barycentric Osculating Orbital Elements for Comet C/2007 W1 (Boattini)". Retrieved 13 April 2011. (Solution using the Solar System Barycenter and barycentric coordinates. Select Ephemeris Type:Elements and Center:@0)
  3. ^ a b c d "JPL Small-Body Database Browser: C/2007 W1 (Boattini)". Jet Propulsion Laboratory. 31 August 2008. Retrieved 13 April 2011.
  4. ^ a b Tammy Plotner (12 June 2008). "Comet Boattini Sails Towards the Sun". Universe Today. Retrieved 13 April 2011.
  5. ^ "Comet for Windows magnitude plot for C/2007 W1". aerith.net. Retrieved 13 April 2011.
  6. ^ "IAUC 8931: NR Tri AUSTRALIS = N Tri AUSTRALIS 2008; C/2007 W1". IAU Central Bureau for Astronomical Telegrams. 4 April 2008. Retrieved 13 April 2011.
  7. ^ Math: 10' * 60" / 206265 * 0.66AU * 149,597,870.7km = 287,207 km
  8. ^ "JPL Close-Approach Data: C/2007 W1 (Boattini)". 31 August 2008. Retrieved 13 April 2011.

External links

  • Orbital simulation from JPL (Java) / Horizons Ephemeris
  • Look quick to spot a bright comet (Astronomy 20 May 2008)
  • Comet Boattini Brightens (Sky and Telescope 16 May 2008)
  • Comet Boattini Sails Towards the Sun (Universe Today 12 June 2008)
  • C/2007 W1 ( Boattini ) – Seiichi Yoshida @ aerith.net (with pictures taken by different astronomers around the world)
  • Reconstructing the Morphology of an Evolving Coronal Mass Ejection (1 June 2008)