BAA Comet Section : Comets discovered in 2013
Updated 2013 May 13
When observing a comet please try to forget how bright you think the comet
should be, what it was when you last viewed it, what other observers think
it is or what the ephemeris says it should be.
The equations for the light curves of comets that are currently visible
use only the raw observations and should give a reasonable prediction for
the current brightness. If the comet has not yet been observed or has
gone from view a correction for aperture is included, so that telescopic
observers should expect the comet to be fainter than given by the equation.
The correction is about 0.033 per centimetre. Values for the r parameter
given in square brackets [ ] are assumed. The form of the light curve is
either the standard m = H0 + 5 log d + K0 log r or the linear brightening
m = H0 + 5 log d + L0 abs(t - T + D0) where T is the date of perihelion,
t the present and D0 an offset, if L0 is +ve the comet brightens towards
perihelion and if D0 is +ve the comet is brightest prior to perihelion.
Observations of new comets in 2013 are given in ICQ format. More
recent ones may be available in TA format from the main page.
Full details of recently discovered objects will not appear until they are
available on the CBAT web pages, which is usually a fortnight after the
publication of the IAUC.
2013 A1 (Siding Spring)
An 18th magnitude comet was discovered at Siding Spring on January 3.54. Follow-up
observations led to pre-discovery observations from the Catalina Sky Survey made on
2012 December 8. It was discovered when still 7.2 au from the Sun, and does not
reach its 1.4 au perihelion until 2014 October. [MPEC 2013-A14, 2013 January 5] It will be a southern hemisphere
object when at its brightest of around 7th magnitude, and will have faded to around
10th magnitude when it enters UK skies in 2015 January. The comet will pass very
close to Mars on 2014 October 19 at 21:00, missing by a nominal 0.0007 au. This is
based on 134 observations over a 74 day arc when the comet is still 6.7 au from the
Earth. The real errors are therefore likely to be larger than the published nominal
errors, though at least JPL does publish the errors, whereas the MPECs do not. Both
JPL and MPEC give far greater precision to the published elements than is warranted by the
error bars.
2013 A2 (P/Scotti)
Jim Scotti discovered a 20th magnitude comet in Spacewatch images taken with the 0.9-m f/3 reflector
at Kitt Peak on January 6.29. The
preliminary orbit was based on a two day arc, yet gave values to five significant figures.
[MPEC 2013-A45, 2013 January 8] It has a period of 8 years and was at perihelion at
2.2 au in February.
2013 A3 (P/LINEAR)
Jim Scotti recovered 2005 YQ127 in Spacewatch II images taken with the 1.8-m f/2.7 reflector
at Kitt Peak on January 7.10. It has a period of 7.6 years and is at perihelion at 1.9 au in June, 0.12
days later than predicted from the discovery apparition. [MPEC 2013-B18, 2013 January 18]
2013 AL76 (P/Catalina)
A 20th magnitude asteroid discovered by the Catalina Sky Survey on January 14.21, was found to
be cometary during follow-up
observations by professional and amateur astrometrists, including Peter Birtwhistle, Gary Hug and
Hirohisa Sato.
The comet was at perihelion at 2.0 au in 2012 December and has a period of around 16
years. [MPEC 2013-B77, 2013 January 23]
A/2013 AS105 [ESAOGS]
This unusual asteroid was discovered by the ESA Optical Ground Station at Tenerife with the 1.0m
reflector on January 15.07. The initial orbit gave a period of around 160
years with perihelion at
5.4 au in 2011 May. [MPEC 2013-B21, 2013 January 18, 11-day orbit].
Aphelion was at around 55 au.
In this orbit it could approach to within 0.5 au of Jupiter. The Tisserand parameter
of the orbit with respect to Jupiter was 2.84. Such an orbit is typical of a potential Jupiter family comet.
The object was subsequently linked to 2010 AO137 with other observations back to
2007. The more definitive orbit is less interesting, with no Jupiter encounters, and
a period of 65 years. Tj is 2.93. [MPEC 2013-B21, 2013 January 19]
2013 B1 (P/McNaught)
Jim Scotti recovered 2006 K2 in Spacewatch II images taken with the 1.8-m f/2.7 reflector
at Kitt Peak on January 19.53. It has a period of 7.1 years and is at perihelion at 2.1 au in August, 0.17
days earlier than predicted from the discovery apparition. [MPEC 2013-B58, 2013 January 21]
2013 B2 (Catalina)
The Catalina Sky Survey discovered a 19th magnitude comet on January 16.23. [MPEC 2013-B84, 2013 January 23]
It is at perihelion in July at 3.7 au.
2013 BL76 (Lemmon)
Elements for a 21st magnitude object discovered by the Mt Lemmon Survey on January 20.08 are
listed amongst those of comets. It is also classed as Centaur/SDO.
The object was at perihelion at 8.37 au in 2012 October and has a slightly retrograde orbit
with a period of around 40,000 years. [MPEC 2013-C12, 2013 February 3]
A/2013 BN27 [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m
Schmidt on January 17.33. The initial retrograde orbit gave a period of around 20
years with perihelion at
1.4 au in 2012 October. [MPEC 2013-B64, 2013 January 21, 4-day orbit].
Aphelion was at around 13 au.
The Tisserand parameter of the orbit with respect to Jupiter was 0.52.
2013 C1 (P/Larsen)
Jim Scotti recovered 2004 H2 in Spacewatch II images taken with the 1.8-m f/2.7 reflector
at Kitt Peak on February 5.50. It has a period of 9.6 years and is at perihelion at 2.6 au in December, 0.58
days earlier than predicted from the discovery apparition. [MPEC 2013-C25, 2013 February 6]
2013 C2 (Tenagra)
Michael Schwartz and Paulo Holvorcem discovered a very distant comet on 2013 February 14.24 at the Tenagra II Observatory
in Arizona. At discovery the comet was around 19th magnitude and over 9 au from the
Earth. [MPEC 2013-D22, 2013 February 17] Perihelion is at 9.1 au in 2015
September. It has a period of around 60 years.
2013 CE31 (281P/MOSS)
Claudine Rinner at the Morocco Oukaimeden Sky Survey (MOSS) discovered an object on February 5.11,
that was initially flagged as an asteroid. Pre-discovery images were found in Spacewatch data from January.
Cometary features were found.
It reached perihelion at 4.0 au in 2012 May and has a period of around 11 years.
With further astrometry leading to an improved orbit, Maik Meyer found and measured the
comet in NEAT images from February and March 2002, and the comet was also found in
Spacewatch images from 2000 November.
A/2013 CY133 [Pan-STARRS]
This unusual asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on February 14.40. The asteroid has a period of around 27
years with perihelion at
5.5 au in 2014 May. [MPEC 2013-D25, 2013 February 18, 4-day orbit].
Aphelion was at around 12 au. It can pass within 0.5 au of Jupiter.
The Tisserand parameter of the orbit with respect to Jupiter was 2.92.
2013 D1 (Holvorcem)
Paulo Holvorcem discovered a comet on 2013 February 16.31 with the 0.41m astrograph at the Tenagra II Observatory
in Arizona. At discovery the comet was around 19th magnitude. [MPEC 2013-D41, 2013 February 20]
It has perihelion at 2.5 au in 2013 April. It has a period of around 40 years.
2013 E1 (McNaught)
Rob McNaught discovered a 19th magnitude comet on March 4.74 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet reaches perihelion at 7.8 au in 2013 June. The latest orbit is strongly
hyperbolic.
2013 E2 (Iwamoto)
Masayuki Iwamoto discovered a 14th magnitude comet on images taken with his 10cm refractor at Tokushima on March 10.83.
The comet was near perihelion at 1.4 au and is just over 40 degrees elongation from the Sun in the dawn sky.
Calculations by Hirohisa Sato show that the comet is in a long period orbit. Marco Antônio Coelho Goiato
estimated the comet at about 11.0 in his 0.22-m reflector on March 23.35.
2013 EV9 (P/Spacewatch)
A 19th magnitude asteroid was discovered by Spacewatch on March 2.28 with the 0.9m reflector.
Cometary characteristics were noted in images taken by Hidetaka Sato in 2013 April using
the remote 0.51m telescope at the iTelescope Observatory at Siding Spring, and confirmed
by other observers, and earlier observations were found from 2013 February. The comet was at perihelion at
2.1 au in 2013 April and has a period of around 8 years. [MPEC 2013-J07, 2013 May 2]
This was another confirmation of cometary features by the T3 project. Andrew Lowe quickly reported that he found astrometry from 1996 and 2005 and that the comet had
made a number of approaches to within 0.5 au of Jupiter between 1600 and 2400.
2013 EW90 (P/Tenagra)
Michael Schwartz and Paulo Holvorcem discovered an asteroid like object of 19th magnitude on 2013 March 3.19
at the Tenagra II Observatory
in Arizona. Later observations then showed cometary features. [MPEC 2013-J52, 2013 May 13]
Perihelion was at 3.3 au in 2012
October. It has a period of around 8 years.
2013 F1 (Boattini)
Andreas Boattini discovered an 18th magnitude comet on March 23.34 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. The comet was at perihelion at 1.9 au in 2012 December.
2013 F2 (Catalina)
An 18th magnitude comet was discovered on March 24.18 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. Pre-discovery images from 2012 December, 2013 January, and March were found
in Pan-STARRS data. The comet is at perihelion at 6.2 au in 2013 April.
2013 F3 (McNaught)
Rob McNaught discovered a 17th magnitude comet on March 29.76 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet reaches perihelion at 2.3 au in 2013 May. It has a period of around 80
years.
2013 G1 (Kowalski)
Richard Kowalski discovered an 18th magnitude comet on April 2.43 on images taken during the Mt Lemmon Survey with
the 1.5m reflector. This was the 150th comet discovered by the Catalina
/Mt Lemmon Sky Survey. The orbital inclination is low, and an orbit computation by
Hirohisa Sato suggests an elliptical orbit with a period of 17 years and perihelion at 3.4
au in 2013 November is fitted by the astrometry.
2013 G2 (McNaught)
Rob McNaught discovered a 17th magnitude comet on April 8.72 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet was at perihelion at 2.1 au in 2012 December. This was Rob McNaught's 75th discovery.
Elements by Hirohisa Sato suggest an orbit with a period of about 110 years and
perihelion at 1.8 au in 2012 November.
2013 G3 (PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on April 10.42. The discovery MPEC reported
that it reaches perihelion at 4.3 au in 2015 January and
has a period of 33.2 years.
The MPEC orbit was based on only a four day arc and seemed unduly precise for this limited amount of data. As a contrast the JPL
orbit viewed on April 16 was hyperbolic! This indicates that not too much credence should be given on preliminary orbits - they
are an aid to predicting the position over the next few days, but not much more. The
latest orbit [MPEC 2013-H38, 2013 April 23] gives perihelion at 3.8 au in 2014 November.
2013 G4 (P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on April 12.49. It was at perihelion at 2.6 au in 2013
February and
has a period of around 10 years.
2013 G5 (Catalina)
An 18th magnitude comet was discovered on April 13.46 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. The initial MPEC orbit puts the comet at perihelion at 0.9 au in 2013 September.
The JPL 1-sigma uncertainty is around 3 days. JPL give a MOID of 0.08 au, so a meteor shower is a possibility.
2013 G6 (Lemmon)
A 19th magnitude comet was discovered on April 13.48 on images taken during the Mt Lemmon Survey with
the 1.5m reflector. It will reach perihelion in 2013 July at 2.1 au.
2013 G7 (McNaught)
Rob McNaught discovered an 18th magnitude comet on April 13.65 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet will reach perihelion at 4.7 au in 2014 March.
2013 G8 (PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on April 14.60. [MPEC 2013-H22, 2013 April 19]. It reaches perihelion at
5.1 au in 2013 November.
2013 G9 (Tenagra)
Michael Schwartz and Paulo Holvorcem discovered a distant comet on 2013 April 15.39 at the Tenagra II Observatory
in Arizona. At discovery the comet was around 20th magnitude and over 6 au from the
Earth. [MPEC 2013-H23, 2013 April 19] Perihelion is at 5.0 au in 2015
January.
A/2013 GY54 [Pan-STARRS]
This unusual asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on April 4.38. The asteroid has a period of around 50 years with perihelion at
4.6 au in 2014 October. [MPEC 2013-G47, 2013 April, 34-day orbit].
Aphelion is at around 22 au. The Tisserand parameter of the orbit with respect to Jupiter was
2.78.
2013 H1 (La Sagra)
The La Sagra team at the OAM Observatory discovered an 18th magnitude comet on April 19.11 with the 0.45m reflector.
The comet is at perihelion at 2.6 au in 2013 June. [MPEC 2013-H27, 2013 April 22]
2013 H2 (Boattini)
Andreas Boattini discovered an 18th magnitude comet on April 22.45 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-H45, 2013 April 25] The preliminary MPEC orbit suggests that the
comet was at perihelion at 2.5 au in 2011 March and has a period of 36.5 years. This is based on a three day arc.
A/2013 HA [Mt Lemmon]
This unusual asteroid was discovered during the Mt Lemmon survey with the 1.5m
telescope on April 16.24. The orbit has a period of around 10
years with perihelion at
1.7 au in 2013 May. [MPEC 2013-H14, 2013 April 17, 3-month orbit].
The Tisserand parameter of the orbit with respect to Jupiter is 2.55 and the object can approach within 0.5 au of the planet.
2013 J1 (P/McNaught)
Jim Scotti recovered 2007 H1 with the Spacewatch 1.8m reflector on May 1.41. The comet will return 0.22 days earlier than
predicted.
2013 J2 (P/McNaught)
Rob McNaught discovered an 18th magnitude comet on May 8.75 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet will reach perihelion at 2.1 au in 2013 August. [MPEC 2013-J38, 2013 May 10]
2013 J3 (McNaught)
Rob McNaught discovered a 17th magnitude comet on May 8.55 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet is near perihelion at 4.0 au. [MPEC 2013-J40, 2013 May 11]
2013 J4 (P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on May 5.26. It will reach perihelion at 2.3 au in 2013
July and
has a period of around 16 years.
A/2013 JD4 [Mt Lemmon]
This unusual asteroid was discovered during the Mt Lemmon survey with the 1.5m
telescope on May 3.32. The orbit has a high inclination with a period of around 40
years and perihelion at
1.6 au in 2012 December. [MPEC 2013-J19, 2013 May 5, 2-day orbit].
The Tisserand parameter of the orbit with respect to Jupiter is 0.91 and the object can approach within 0.4 au of the planet.
Ephemerides of current comets are available on the CBAT
ephemeris page and positions of newly discovered comets are on the
NEO confirmation page.
More information on LINEAR. A list of comets
discovered by selected search programs.
The Northumberland refractor
is the telescope that was used in the search for Neptune.
It now has a 0.30-m f20 doublet lens which gives a stellar limiting magnitude of around
15 at the zenith on good nights.
The Thorrowgood refractor was
built in 1864 and has a 0.20-m f14 doublet lens.
Published by Jonathan Shanklin. Jon Shanklin - jds@ast.cam.ac.uk