479P/Elenin

479P/Elenin, with provisional designation P/2011 NO₁ (Elenin), is a periodic comet with an orbital period estimated at 13.3 years.^[4]

479P/Elenin

Comet 479P/Elenin photographed on 10 April 2024
Discovery
Discovered by	Leonid Elenin[1] 0.45-m reflector (H15)[2][3]
Discovery date	7 July 2011[2]
Designations
MPC designation	P/2011 NO1 P/2023 WM26
Orbital characteristics
Epoch	15 June 2020[4] (JD 2459015.5)
Aphelion	9.98 AU (Q)
Perihelion	1.24 AU (q)
Semi-major axis	5.61 AU (a)
Eccentricity	0.779
Orbital period	13.28 yr
Inclination	15.40°
Longitude of ascending node	295.81°
Argument of periapsis	263.64°
Last perihelion	20 January 2011[4]
Next perihelion	10 September 2037
TJupiter	2.183
Earth MOID	0.38 AU
Comet total magnitude (M1)	15.2[4]

Observational history

The comet was discovered on 7 July 2011^[2] when the comet was 2.38 AU from the Sun and 1.4 AU from the Earth and had an apparent magnitude of 19.5. It had come to perihelion (closest approach to the Sun) around 20 January 2011 at 1.2 AU from the Sun.^[4] P/2011 NO1 was the second comet discovered by Leonid Elenin. The first comet discovered by Elenin was comet C/2010 X1. Both comets were discovered with the aid of the automatic detection program CoLiTec.^[5] It came to opposition 178.6° from the Sun on 22 July 2011 in the constellation Sagittarius.

On 29 January 2013 the Minor Planet Center awarded Leonid Elenin a 2012 Edgar Wilson Award for the discovery of comets by amateurs.^[6]

Maik Meyer proposed that asteroid 2023 WM₂₆, which was discovered by PanSTARRS on 18 November 2023, is the return of P/2011 NO₁ (Elenin).^[7][8] The link was later confirmed by Shuichi Nakano and Daniel Green.^[9] The 2024 apparition was the most favorable in decades, with the comet approaching 0.62 AU to Earth on 4 May 2024, one day before perihelion. The comet appeared gasy and diffuse and brightened to an apparent magnitude of 10 to 11.^[10]

The radius of the nucleus is estimated to be less than one kilometre.^[11]