Discovery | |
---|---|
Discovered by | Donald Machholz |
Discovery date | 2004 |
Designations | |
Comet Machholz | |
Orbital characteristics | |
Epoch | 2453415.5 (February 14, 2005) |
Aphelion | ~5000 AU (inbound) [1] ~1100 AU (outbound) |
Perihelion | 1.205 AU |
Eccentricity | 0.9995 |
Orbital period | ~130,000 yr (inbound) [1] ~12,400 yr (outbound) |
Inclination | 38.6° |
Last perihelion | January 24, 2005 |
Comet Machholz, formally designated C/2004 Q2, is a long-period comet discovered by Donald Machholz on August 27, 2004. It reached naked eye brightness in January 2005. Unusual for such a relatively bright comet, its perihelion was farther from the Sun than the Earth's orbit.
Given the orbital eccentricity of this object, different epochs can generate quite different heliocentric unperturbed two-body best-fit solutions to the aphelion distance (maximum distance) of this object. For objects at such high eccentricity, the Suns barycentric coordinates are more stable than heliocentric coordinates. Using JPL Horizons the barycentric orbital elements for epoch 2050 generate a semi-major axis of 537 AU and a period of approximately 12,400 years. [1]
There are six other long-period comets named Machholz: C/1978 R3 (a.k.a. 1978 XIII, 1978l), C/1985 K1 (a.k.a. 1985 VIII, 1985e), C/1988 P1 (a.k.a. 1988 XV, 1988j), C/1992 N1 (a.k.a. 1992 XVII, 1992k), C/1994 T1 (a.k.a. 1994 XXVII, 1994r), and C/2010 F4. In addition, there are C/1992 F1 (Tanaka-Machholz), C/1994 N1 (Nakamura-Nishimura-Machholz) and C/2018 V1 (Machholz-Fujikawa-Iwamoto).
JPL Horizons On-Line Ephemeris System provides access to key Solar System data and flexible production of highly accurate ephemerides for Solar System objects.
Comet C/2006 M4 (SWAN) is a non-periodic comet discovered in late June 2006 by Robert D. Matson of Irvine, California and Michael Mattiazzo of Adelaide, South Australia in publicly available images of the Solar and Heliospheric Observatory (SOHO). These images were captured by the Solar Wind ANisotropies (SWAN) Lyman-alpha all-sky camera on board the SOHO. The comet was officially announced after a ground-based confirmation by Robert McNaught on July 12.
Comet McNaught, also known as the Great Comet of 2007 and given the designation C/2006 P1, is a non-periodic comet discovered on 7 August 2006 by British-Australian astronomer Robert H. McNaught using the Uppsala Southern Schmidt Telescope. It was the brightest comet in over 40 years, and was easily visible to the naked eye for observers in the Southern Hemisphere in January and February 2007.
Comet Zhu–Balam, formally designated C/1997 L1, is a long-period comet first identified by David D. Balam on June 8, 1997, and originally photographed by Jin Zhu on June 3, 1997. The comet is estimated at 10 kilometres in diameter with a period of approximately 36,895 years.
(308933) 2006 SQ372 is a trans-Neptunian object and highly eccentric centaur on a cometary-like orbit in the outer region of the Solar System, approximately 123 kilometers (76 miles) in diameter. It was discovered through the Sloan Digital Sky Survey by astronomers Andrew Becker, Andrew Puckett and Jeremy Kubica on images first taken on 27 September 2006 (with precovery images dated to 13 September 2005).
Comet Lulin, formal designation C/2007 N3, Traditional Chinese:鹿林彗星) is a non-periodic comet. It was discovered by Ye Quanzhi and Lin Chi-Sheng from Lulin Observatory. It peaked in brightness at magnitude between +4.5 and +5, becoming visible to the naked eye, and arrived at perigee for observers on Earth on February 24, 2009, and at 0.411 AU from Earth.
C/1992 J1 (Spacewatch) is a comet that was discovered 1 May 1992 by David Rabinowitz of the Spacewatch Project. This was the first comet to be discovered using an automated system.
C/2007 Q3 , is an Oort cloud comet that was discovered by Donna Burton in 2007 at Siding Spring Observatory in New South Wales, Australia. Siding Spring came within 1.2 astronomical units of Earth and 2.25 AU of the Sun on October 7, 2009. The comet was visible with binoculars until January 2010.
(523622) 2007 TG422 (provisional designation 2007 TG422) is a trans-Neptunian object on a highly eccentric orbit in the scattered disc region at the edge of Solar System. Approximately 260 kilometers (160 miles) in diameter, it was discovered on 3 October 2007 by astronomers Andrew Becker, Andrew Puckett and Jeremy Kubica during the Sloan Digital Sky Survey at Apache Point Observatory in New Mexico, United States. According to American astronomer Michael Brown, the bluish object is "possibly" a dwarf planet. It belongs to a group of objects studied in 2014, which led to the proposition of the hypothetical Planet Nine.
C/1999 F1 (Catalina) is one of the longest known long-period comets. It was discovered on March 23, 1999, by the Catalina Sky Survey. The current perihelion point is outside of the inner Solar System which helps reduce planetary perturbations to this outer Oort cloud object and keep the inbound and outbound orbital periods similar.
(668643) 2012 DR30 is a trans-Neptunian object and centaur from the scattered disk and/or inner Oort cloud, located in the outermost region of the Solar System. The object with a highly eccentric orbit of 0.99 was first observed by astronomers with the Spacewatch program at Steward Observatory on 31 March 2009. It measures approximately 188 kilometers (120 miles) in diameter.
(709487) 2013 BL76 is a trans-Neptunian object and centaur from the scattered disk and Inner Oort cloud approximately 30 kilometers in diameter.
2005 VX3 is trans-Neptunian object and retrograde damocloid on a highly eccentric, cometary-like orbit. It was first observed on 1 November 2005, by astronomers with the Mount Lemmon Survey at the Mount Lemmon Observatory in Arizona, United States. The unusual object measures approximately 7 kilometers (4 miles) in diameter. It has the 3rd largest known heliocentric semi-major axis and aphelion. Additionally its perihelion lies within the orbit of Jupiter, which means it also has the largest orbital eccentricity of any known minor planet.
C/2014 Q2 (Lovejoy) is a long-period comet discovered on 17 August 2014 by Terry Lovejoy using a 0.2-meter (8 in) Schmidt–Cassegrain telescope. It was discovered at apparent magnitude 15 in the southern constellation of Puppis. It is the fifth comet discovered by Terry Lovejoy. Its blue-green glow is the result of organic molecules and water released by the comet fluorescing under the intense UV and optical light of the Sun as it passes through space.
C/2013 US10 (Catalina) is an Oort cloud comet discovered on 31 October 2013 by the Catalina Sky Survey at an apparent magnitude of 19 using a 0.68-meter (27 in) Schmidt–Cassegrain telescope. From September 2015 to February 2016 the comet was around apparent magnitude 6. The comet took around a million years to complete half an orbit from its furthest distance in the Oort cloud and should be ejected from the Solar System over many millions of years.
2010 BK118 (also written 2010 BK118) is a centaur roughly 20–60 km in diameter. It is on a retrograde cometary orbit. It has a barycentric semi-major axis (average distance from the Sun) of ~400 AU.
(418993) 2009 MS9, provisionally known as 2009 MS9, is a centaur roughly 30–60 km in diameter. It has a highly inclined orbit and a barycentric semi-major axis (average distance from the Sun) of ~353 AU.
C/2017 U7 (PanSTARRS) is a hyperbolic comet, first observed on 29 October 2017 by astronomers of the Pan-STARRS facility at Haleakala Observatory, Hawaii, United States when the object was 7.8 AU (1.2 billion km) from the Sun. Despite being discovered only 10 days after interstellar asteroid 1I/'Oumuamua, it was not announced until March 2018 as its orbit is not strongly hyperbolic beyond most Oort Cloud comets. Based on the absolute magnitude of 10.6, it may measure tens of kilometers in diameter. As of August 2018, there is only 1 hyperbolic asteroid known, ʻOumuamua, but hundreds of hyperbolic comets are known.
C/2021 O3 (PanSTARRS) is perhaps an Oort cloud comet, discovered on 26 July 2021 by the Pan-STARRS sky survey. It came to perihelion on 21 April 2022 at 0.287 AU (42.9 million km). from the Sun.