450P/LONEOS

For other comets of the same name, see Comet LONEOS.

450P/LONEOS, also known by its formal designations P/2004 A1 and P/2022 Q3, is a distant periodic comet with a 22-year orbit around the Sun.

450P/LONEOS

Infrared image of 450P/LONEOS taken by the Spitzer Space Telescope on 4 March 2007
Discovery[1][2]
Discovery site	LONEOS
Discovery date	13 January 2004
Designations
MPC designation	P/2004 A1, P/2022 Q3
Alternative designations	LONEOS 8
Orbital characteristics[3][4]
Epoch	5 May 2024 (JD 2460800.5)
Observation arc	21.39 years
Earliest precovery date	25 October 2003
Number of observations	629
Aphelion	10.442 AU
Perihelion	5.449 AU
Semi-major axis	7.945 AU
Eccentricity	0.31423
Orbital period	22.396 years
Inclination	10.653°
Longitude of ascending node	124.35°
Argument of periapsis	23.148°
Mean anomaly	332.08°
Last perihelion	25 August 2004
Next perihelion	29 January 2027
TJupiter	2.961
Earth MOID	4.465 AU
Jupiter MOID	0.184 AU
Physical characteristics[3][5]
Mean radius	0.5–3.5 km (0.31–2.17 mi)
Spectral type	(V–R) = 0.51±0.21
Comet total magnitude (M1)	6.7
Comet nuclear magnitude (M2)	11.3

Observational history

Discovery

The comet was discovered as an 18th-magnitude object on CCD images taken by Brian A. Skiff as part of the Lowell Observatory's LONEOS program.^[1] The LONEOS images show the object with a stellar-like appearance, but its motion prompted Skiff to request additional observations. H. R. Miller (Perkins Observatory) and J. Young (Table Mountain Observatory) later found a coma about 4 arcseconds in diameter and a very faint tail about 10 arcseconds in length, confirming its cometary nature.^[1] The first orbital calculations were later published on the Minor Planet Center's website on 13 January 2004, alongside precovery images taken by the Kitt Peak Observatory dating as far back as 18 December 2003.^[2]

Follow-up observations

The comet was successfully recovered from observations taken by the Gemini North Observatory in August 2022, where it was noted to be 4.5 magnitudes fainter than previously predicted.^[6][7]

Orbit

As of 2024^[update], 450P/LONEOS has a heliocentric orbit inclined about 10.65 degrees from the ecliptic. Its perihelion distance is about 5.45 AU (815 million km) while its aphelion goes as far back as 10.44 AU (1.562 billion km) from the Sun.^[4] Orbital calculations indicated that it made a close encounter with Saturn in 1992, when it came within 0.031 AU (4.6 million km) to the giant planet.^[3] This resulted in its semimajor axis to be significantly decreased by 5.2 AU (780 million km).^[8] A long-term orbital investigation indicated that this is likely its first sojourn to the inner Solar System as it transitions from a centaur into a Jupiter-family comet.^[8][9]

Physical characteristics

Based on its measured dust activity, the nucleus of 450P/LONEOS is likely somewhere between 0.5 km (0.31 mi) to 3.5 km (2.2 mi) in radius.^[5]