289P/Blanpain
Lost comet rediscovered after 194 years, linked to Phoenicid meteors.
289P/Blanpain is a Jupiter-family comet that orbits the Sun every 5.2 years. It was first spotted on 28 November 1819 by Jean-Jacques Blanpain, who noted its "very small and confused nucleus." Jean-Louis Pons independently found it a week later. After that, the comet vanished from view and was labeled "D" for disappeared or dead.
For nearly two centuries, Blanpain was considered lost. Then, in 2003, astronomers calculated that the orbit of a newly discovered asteroid, 2003 WY25, closely matched the missing comet. On 12 December 2003, that object passed within 0.025 AU of Earth. In 2005, David C. Jewitt used the University of Hawaii’s 2.2-meter telescope on Mauna Kea and detected a faint coma around 2003 WY25, suggesting it was either the lost comet or a fragment of it. The object was officially reclassified as periodic comet 289P in July 2013, after the Pan-STARRS survey caught it during a major outburst.
That outburst, one of the largest ever observed for a comet, saw 289P brighten by 9 magnitudes. First spotted in Pan-STARRS images on 4 July 2013 at magnitude 20, it soon reached magnitude 17.5, with a coma about 30 arcseconds across and a broad tail. The comet shed roughly 108 kg of dust—about 1% of its total mass—while 3.9 AU from the Sun.
Better views came near and after the December 2019 perihelion. On 11 January 2020, 289P passed Earth at 0.091 AU. Its next close approach is predicted for 6 November 2035, at 0.082 AU.
The nucleus is tiny. Assuming an albedo of 0.04 (typical for short-period comets), its radius is about 160 meters, though the coma and unknown phase function introduce uncertainty. At the time of those measurements, it was the smallest known cometary nucleus. NEOWISE observations from 2019–20 suggest a rotational period of either 8.85 or 15.6 hours, with the shorter period more likely. The comet ejected 4100±200 kg of dust inbound and 1700±200 kg outbound, with dust production rates of 0.01–0.02 kg/s and a dust-to-gas ratio between 2 and 6. Its fractional active area, 3.8±1.9 × 10⁻⁵, is the smallest ever reported. The lack of a 4.6 μm excess indicates negligible CO₂ and CO. Its perihelion-normalized nongravitational acceleration is about an order of magnitude weaker than that of well-studied comets, consistent with weak outgassing.
Quick Facts
- Discovery Ref
- Kronk_2003 · CBET_3574
- Discoverer
- Jean-Jacques Blanpain
- Discovery Site
- Marseille, France
- Discovery Date
- 28 November 1819 / 22 November 2003MPEC_2003-W41
- Mpc Name
- D/1819 W1, P/2003 WY · 25
- Designations
- 1819 IVICQ1
- Orbit Ref
- MPC
- Epoch
- 21 November 2025 (JD 2461000.5)
- Obs
- 690
- Semimajor
- 3.044 AU
- Perihelion
- 0.954 AU
- Aphelion
- 5.133 AU
Facts from the source article.
Lore & Background
The comet was discovered by Jean-Jacques Blanpain on 28 November 1819, who described it as having a 'very small and confused nucleus'. An independent discovery was made by Jean-Louis Pons on 5 December 1819. The comet was subsequently lost and given the designation 'D' (Disappeared or Dead). In 2003, orbital elements of asteroid 2003 WY25 were calculated by Marco Micheli and others to be a probable match for the lost comet. On 12 December 2003, it approached Earth at 0.025 AU. Observations in 2005 by David C. Jewitt using the University of Hawaii 2.2 m telescope revealed a faint coma, supporting the theory that 2003 WY25 is the lost comet or part of it. The comet was officially established as periodic comet 289P in July 2013 after being rediscovered by the Pan-STARRS survey during an outburst event.
The comet underwent a major outburst in July 2013, brightening by 9 magnitudes—one of the largest observed comet outbursts. It was first spotted by Pan-STARRS on 4 July 2013 at magnitude about 20, then brightened to about 17.5 with a coma 30 arcseconds across and a broad tail. It lost about 108 kg of dust, about 1% of its mass, while 3.9 AU from the Sun. The nucleus is quite small; assuming an albedo of 0.04, its radius is about 160 m, making it at that time the smallest known cometary nucleus. Observations by NEOWISE in 2019–20 indicate a rotational period of 8.8536±0.386 hours or 15.6 hours, with the former more likely. The comet has negligible amounts of CO2 and CO, and its nongravitational acceleration is about an order of magnitude smaller than the trend for well-studied comets, consistent with weak outgassing.
Reader's Guide
289P/Blanpain holds significance as a lost comet that was recovered after nearly two centuries, bridging historical and modern astronomy. Its rediscovery via asteroid 2003 WY25 and confirmation through a major outburst in 2013 highlight the dynamic nature of small solar system bodies. The comet is the probable source of the Phoenicid meteor stream, first observed as a storm in 1956, with analysis of 2003 WY25 orbits supporting this link. Elevated Phoenicid activity in December 2014 further indicates the comet's ongoing dust production. However, a 2025 study expressed doubt that 289P/Blanpain is the sole parent body, as its nucleus is too small to account for the total meteoroid mass, suggesting contributions from comets 46P/Wirtanen and 104P/Kowal. The comet has been proposed as the primary target for Japan's Next Generation Small-Body Return mission, aiming to return a comet sample, and as a backup target for ESA's Comet Interceptor mission, with a potential flyby by 23 November 2035. Its small nucleus, weak outgassing, and favorable orbital characteristics make it a scientifically valuable object for understanding comet evolution and meteor stream formation.
Frequently Asked Questions
Who discovered 289P/Blanpain and when?
Jean-Jacques Blanpain first observed the comet on 28 November 1819, describing its nucleus as very small and confused. Jean-Louis Pons independently recovered it roughly a week later.
Why was 289P/Blanpain declared lost?
After its single 1819 apparition the comet vanished and was given the "D" designation, meaning it was presumed dead or irrecoverable. For about 194 years no one could locate it again.
How did astronomers find 289P/Blanpain after nearly two centuries?
In 2003, orbital calculations showed that the newly catalogued asteroid 2003 WY25 followed a path matching Blanpain's predicted trajectory. The object's close pass within 0.025 AU of Earth on 12 December 2003 confirmed the long-lost comet had been found.
What are 289P/Blanpain's basic physical and orbital characteristics?
This Jupiter-family comet circles the Sun every 5.2 years and has a nucleus roughly 160 meters across. Its rotation period is estimated at around 8.85 hours, though some measurements suggest 15.6 hours.
Is 289P/Blanpain connected to a meteor shower?
Yes — the comet is the parent body of the Phoenicid meteor shower. Its minimum orbit intersection distance with Earth is only about 0.015 AU (roughly 2.2 million km), placing it among the closer near-Earth objects.
More in Periodic Comets 1-24
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