13P/Olbers

Observational history

Discovery

Heinrich Wilhelm Matthias Olbers discovered the comet on 6 March 1815 and described it as small. The comet came to perihelion on 26 April 1815 and reached an apparent magnitude of about 5, and was faintly visible by naked eye. Its orbit was first computed by Carl Friedrich Gauss on March 31 as parabolic, and Friedrich Bessel calculated an orbital period of 73.9 years using observations from June. Calculations by other astronomers during that era resulted anywhere between 72 and 77 years. Modern solutions give an orbital period of 74.9 years for the 1815 epoch.

1887

There were unsuccessful searches for the comet throughout 1887, until it was accidentally found by William Robert Brooks on 25 August 1887. The comet brightened to an apparent magnitude of about 9. On 28 July 1887 the comet passed 0.081 AU from Mars and then passed perihelion on 8 October 1887.

1956

The comet was recovered on 4 January 1956 by Antonín Mrkos. The comet was then located in Eridanus and its apparent magnitude was estimated to be 16. He then found the comet in plates obtained by the McDonald Observatory on 12 November 1955. The comet passed perihelion on 19 June 1956 and reached an apparent magnitude of 6.5, while its tail was about one degree long.

2024

The comet was recovered on 24 August 2023 by Alan Hale with the Las Cumbres Observatory at Siding Spring, and then additional pre-recovery images from August 13 were located. The comet then had an estimated apparent magnitude of about 22. It came to perihelion on June 30, 2024, when it was 1.18 AU from the Sun and 1.94 AU from Earth. It was expected to brighten to about apparent magnitude 7−8 but peaked at 6–7.

2094

Before the 2023 recovery, while the last observation was in 1956, Kinoshita calculated that the comet would come to a future perihelion passage (closest approach to the Sun) on 22 March 2094. Accounting for observations in 2023–4, the nominal time of perihelion passage is now calculated to be 20 March 2094.

Meteor showers

There is some speculation that 13P/Olbers has an associated annual meteor shower on Mars coming from the direction of Beta Canis Majoris. The minimum orbit intersection distance of the orbits of comet Olbers and Mars is 0.0266 AU and the meteors impact the planet with a velocity of 27 km/s. An intersection distance of less than 0.1 AU and an impact speed high enough for the meteors to become ablaze are considered good predictors for a potential meteor shower.

Notes

References

• 13P at Gary W. Kronk's Cometography
• 13P at Kazuo Kinoshita's Comets
• 13P at Seiichi Yoshida's Comet Catalog

References

1. {{mpc. 13p
2. (1 January 1888). "The Olbers-Brooks Comet". The Observatory.
3. (1956). "Comet Notes". Publications of the Astronomical Society of the Pacific.
4. (29 April 2024). "COMET 13P/OLBERS". Central Bureau for Astronomical Telegrams.
5. "Meteor Showers And Their Parent Bodies".
6. (December 2004). "Predicting Martian and Venusian Meteor Shower Activity". Earth, Moon, and Planets.