324P/La Sagra
Periodic comet
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324P/La Sagra is an active asteroid with an orbital period of 5.44 years. It has been found to be active in more than one perihelia, indicating that the source of activity is sublimation.[5]
324P/La Sagra by Hubble Space Telescope on 7 December 2015 | |
| Discovery[1] | |
|---|---|
| Discovered by | La Sagra Observatory |
| Discovery date | 14 September 2010 |
| Designations | |
| P/2010 R2 P/2015 K3 | |
| Orbital characteristics[2] | |
| Epoch | 12 December 2012 |
| Earliest precovery date | 12 August 2010 |
| Aphelion | 3.569 AU |
| Perihelion | 2.618 AU |
| Semi-major axis | 3.094 AU |
| Eccentricity | 0.1538 |
| Orbital period | 5.44 years |
| Inclination | 21.42° |
| 270.65° | |
| Argument of periapsis | 58.90° |
| Last perihelion | 5 May 2021 |
| Next perihelion | 14 October 2026[3] |
| Earth MOID | 1.67 AU |
| Jupiter MOID | 1.83 AU |
| Physical characteristics | |
Mean diameter | 1.6 km [2] 1.1±0.1 km [4] |
| Comet total magnitude (M1) | 7.5 [2] |
| Comet nuclear magnitude (M2) | 15.6 [2] |
The asteroid was first noticed in images taken by La Sagra Observatory on 14.9 September 2010 with a 0.45-m f/2.8 reflector by J. Nomen, who also noticed it was diffuse. The asteroid was also found in images obtained in 13 August, but showed no cometary features. On 17 September was noticed that it has a coma with a diameter of 6 arcseconds and a tail 11 arcseconds long.[1]
The comet was recovered on 21 March 2015 by Scott S. Sheppard at Las Campanas Observatory.[6] The object was one magnitude brighter than expected, indicating dust production at a heliocentric distance of 2.8 AU, and in May and June a dust tail was observed.[5]
The nucleus of the comet has an effective radius of 0.55±0.05 km.[4] The source of activity is water ice sublimation from an area that covers about 0.2% of the surface of the nucleus. The mass loss of the comet is estimated to be 0.2 kg/s[7] and reached 4 kg/s during the 2010 perihelion.[8]
It exhibits non-gravitational acceleration due to outgassing.[9]