C/2012 E2 (SWAN)

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Comet C/2012 E2 (SWAN) was a Kreutz group sungrazing comet discovered by Vladimir Bezugly in publicly available images taken by the SWAN instrument (Solar Wind ANisotropies) on board the SOHO spacecraft. It is recognized for being the first Kreutz sungrazer observed in SWAN imagery.

Contents

Discovery

On March 8, 2012, Ukrainian amateur astronomer Vladimir Bezugly reported an unknown comet in 3 images taken by the SWAN instrument on board the SOHO spacecraft. Further study of this object revealed that it was a Kreutz group sungrazer with a perihelion date on March 15, 2012. This was particularly interesting because no Kreutz sungrazer had ever been bright enough to be observed by the SWAN cameras, not even Comet C/2011 W3 (Lovejoy) which was visible to the naked-eye three months earlier. This meant that Comet SWAN had a chance of being an exceptionally bright comet. [1]

SECCHI and LASCO Observations

The SECCHI HI1 camera on board the STEREO-B spacecraft was the first to observe the comet after the SWAN instrument. It entered the field of view on March 11 and appeared reasonably bright, though not as bright as it could have been. The comet entered the visibility of SOHO's LASCO telescopes on March 13, there too the comet did not appear exceptionally bright, it was fainter in comparison to Comet C/2011 W3 (Lovejoy) at this stage of its orbit. Though it certainly appeared brighter than most sungrazing comets of the Kreutz group. It reached a maximum apparent brightness of mag +1 before it declined in brightness due to disintegration. The comet did not survive perihelion. SECCHI's COR instruments on both STEREO spacecraft also observed the comet's final moments. [2] [1] [3]

Other observations

The reason of the comet's brightness in SWAN remains unknown, though it is thought that the comet experienced an outburst a few days before discovery which rendered it much brighter than it was otherwise. [1] No ground-based observations of the comet were available.

Due to a short 2-day observation arc, the long-term trajectory of the comet is poorly constrained. The orbital period is unknown with an orbital inclination of 144 degrees. [4]

Related Research Articles

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The Solar and Heliospheric Observatory (SOHO) is a European Space Agency (ESA) spacecraft built by a European industrial consortium led by Matra Marconi Space that was launched on a Lockheed Martin Atlas IIAS launch vehicle on 2 December 1995, to study the Sun. It has also discovered over 5,000 comets. It began normal operations in May 1996. It is a joint project between the European Space Agency (ESA) and NASA. SOHO was part of the International Solar Terrestrial Physics Program (ISTP). Originally planned as a two-year mission, SOHO continues to operate after over 25 years in space; the mission has been extended until the end of 2025, subject to review and confirmation by ESA's Science Programme Committee.

<span class="mw-page-title-main">Sungrazing comet</span> Comet that is extremely close to the sun during part of its orbit

A sungrazing comet is a comet that passes extremely close to the Sun at perihelion – sometimes within a few thousand kilometres of the Sun's surface. Although small sungrazers can completely evaporate during such a close approach to the Sun, larger sungrazers can survive many perihelion passages. However, the strong evaporation and tidal forces they experience often lead to their fragmentation.

<span class="mw-page-title-main">Great Comet of 1843</span> Long-period comet visible in March 1843

The Great Comet of 1843, formally designated C/1843 D1 and 1843 I, was a long-period comet which became very bright in March 1843. It was discovered on February 5, 1843, and rapidly brightened to become a great comet. It was a member of the Kreutz Sungrazers, a family of comets resulting from the breakup of a parent comet into multiple fragments in about 1106. These comets pass extremely close to the surface of the Sun—within a few solar radii—and often become very bright as a result.

<span class="mw-page-title-main">Great Comet of 1882</span> Astronomical object

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<span class="mw-page-title-main">Comet White–Ortiz–Bolelli</span>

Comet White–Ortiz–Bolelli was a bright comet which appeared in 1970. It was a member of the Kreutz Sungrazers, a family of comets which resulted from the break-up of a large parent comet several centuries ago. It was already easily visible to the naked eye when first discovered, and reached a maximum apparent magnitude of +1.

<span class="mw-page-title-main">Comet Pereyra</span>

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<span class="mw-page-title-main">Comet McNaught</span> Non-periodic comet

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.

<span class="mw-page-title-main">96P/Machholz</span> Periodic comet with 5 year orbit

Comet 96P/Machholz or 96P/Machholz 1 is a short-period sungrazing comet discovered on May 12, 1986, by amateur astronomer Donald Machholz on Loma Prieta peak, in central California using 130 millimetres (5.1 in) binoculars. On June 6, 1986, 96P/Machholz passed 0.404 AU from the Earth. 96P/Machholz last came to perihelion on January 31, 2023. The comet has an estimated diameter of around 6.4 km (4.0 mi).

<span class="mw-page-title-main">Terry Lovejoy</span> Australian information technologist (born 1966)

Terry Lovejoy is an information technologist from Thornlands, Queensland, Australia, most widely known as an amateur astronomer. He has discovered six comets, including C/2011 W3 (Lovejoy), the first Kreutz Sungrazing comet discovered by ground-based observation in over 40 years. He is also known for popularizing procedures for modifying consumer-grade digital cameras so that they can be used for digital camera astrophotography.

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<span class="mw-page-title-main">Great Southern Comet of 1887</span> Kreutz comet

The Great Southern Comet of 1887, or C/1887 B1 using its International Astronomical Union (IAU) designation, was a bright comet seen from the Southern Hemisphere during January 1887. Later calculations indicated it to be part of the Kreutz Sungrazing group. It came to perihelion on 11 January 1877 at a distance of 0.00483 AU (723 thousand km) with a velocity of 606.1 km/s. Since the Sun has a radius of 696000 km, the comet passed about 27000 km from the surface of the Sun.

<span class="mw-page-title-main">C/2011 L4 (PanSTARRS)</span>

C/2011 L4 (PanSTARRS), also known as Comet PANSTARRS, is a non-periodic comet discovered in June 2011 that became visible to the naked eye when it was near perihelion in March 2013. It was discovered using the Pan-STARRS telescope located near the summit of Haleakalā, on the island of Maui in Hawaii. Comet C/2011 L4 probably took millions of years to come from the Oort cloud. After leaving the planetary region of the Solar System, the post-perihelion orbital period is estimated to be roughly 107000 years. Dust and gas production suggests the comet nucleus is roughly 1 kilometer (0.62 mi) in diameter, while based on the absolute nuclear magnitude and a geometric albedo of 0.04 the diameter of the nucleus is over 2.4 kilometers (1.5 mi). A method based on coma magnitude decay function estimated the effective radius at 2.317 ± 0.190 km.

<span class="mw-page-title-main">C/2011 W3 (Lovejoy)</span> Kreutz Sungrazer comet

Comet Lovejoy, formally designated C/2011 W3 (Lovejoy), is a long-period comet and Kreutz sungrazer. It was discovered in November 2011 by Australian amateur astronomer Terry Lovejoy. The comet's perihelion took it through the Sun's corona on 16 December 2011, after which it emerged intact, though greatly impacted by the event.

<span class="mw-page-title-main">Comet ISON</span> Oort cloud comet

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The Great Comet of 372–371 BC was a comet that is thought to possibly be the source of the Kreutz sungrazer family.

References

  1. 1 2 3 "The 2012 "SWAN-grazer": Comet Lovejoy version 2.0?". Archived from the original on 2018-12-23. Retrieved 2013-03-16.
  2. Musgrave, Ian. "Comet Swan Enters LASCO C2, and STEREO COR1 and 2".
  3. "Bright comet makes SWAN dive into sun today".
  4. "JPL Small-Body Database: C/2012 E2 (SWAN)". Jet Propulsion Laboratory . Retrieved 2023-09-02.