Statistical Investigation and Modeling of Sungrazing Comets Discovered with the<i>Solar and Heliospheric Observatory</i>

Sekanina, Z.

doi:10.1086/324335

Cited by 56 publications

(65 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, most of the small Kreutz objects may have been heavily depleted of water and other volatiles when they split from their parent fragment on a previous apparition. Notable exceptions to this are C/2012 E2 SWAN, the only Kreutz comet to be detected by SOHO-SWAN, which brightened near r −4 H (Ye et al 2014) and several of the historic ground-observed Kreutz (Sekanina 2002b) which survived perihelion and were orders of magnitude larger than typical SOHO-observed Kreutz (e.g., Sekanina 2002b). It is likely that the small Kreutz objects are minimally active or inactive at ordinary heliocentric distances (e.g., beyond ∼ 0.5 AU; ∼ 107 R ).…”

Section: Lightcurve Profilesmentioning

confidence: 96%

“…Interest in the groups' dynamical history was rekindled by the spectacular appearance of three bright members between (e.g., Öpik 1963Kresák 1966;Marsden 1967;Sekanina 1967). The SOLWIND and SMM discoveries, followed soon after by SOHO and eventually STEREO, have yielded extensive investigations into the group's hierarchy and the processes driving its creation (e.g., Weissman 1983;Marsden 1989;Sekanina 2002b). Whilst there is no consensus about the specific fragmentation history of the Kreutz group, most investigators (Marsden 1967(Marsden , 1989Sekanina and Chodas 2002a,b, 2004, 2008 are in agreement about the general picture of the group's evolution.…”

Section: Kreutz Groupmentioning

confidence: 99%

“…Knight et al (2010) showed that if the distribution of small Kreutz comets seen by SOHO during 1996-2005 is representative of the distribution all the way around the Kreutz orbit, then the total mass of all small Kreutz comets is likely smaller than a single ∼ km scale nucleus. At least four of the brightest Kreutz comets of the last 200 years (C/1843 D1, C/1882 R1, C/1963 R1 Pereyra, C/1965 S1 Ikeya-Seki) were likely larger than a km in radius, suggesting that the majority of the mass of the system remains locked in the largest few fragments and that the Kreutz system is still evolutionarily young (Sekanina 2002b;Knight et al 2010). Despite the many spectacular apparitions of Kreutz comets throughout history, the original progenitor need not have been exceptionally large; a comet a few km to tens of km in radius (e.g., C/1995 O1 Hale-Bopp sized or smaller; Weaver et al 1997) could have produced the entire known Kreutz group.…”

Section: Kreutz Groupmentioning

confidence: 99%

See 2 more Smart Citations

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

et al. 2017

View full text Add to dashboard Cite

This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all ob- jects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun's centre, equal to half of Mercury's perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground-and space-based facilities that will allow us to address those science topics.

show abstract

Section: Lightcurve Profilesmentioning

confidence: 96%

Section: Kreutz Groupmentioning

confidence: 99%

Section: Kreutz Groupmentioning

confidence: 99%

See 1 more Smart Citation

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

et al. 2017

View full text Add to dashboard Cite

show abstract

“…We feel that GTO time should definitely be reserved for Dorrit to carry out this search! The sungrazing comets seen in recent years by SOHO all came from a single breakup event (Sekanina 2002). The little SOHO ones all vanish at perihelion, while some of the large sungrazers found earlier from the ground survive (e.g., C/1882R1).…”

Section: Comets: Now You See It Now You Don'tmentioning

confidence: 99%

Astrophysics in 2002

Trimble

Aschwanden

2003

PUBL ASTRON SOC PAC

View full text Add to dashboard Cite

ABSTRACT. This has been the Year of the Baryon. Some low temperature ones were seen at high redshift, some high temperature ones were seen at low redshift, and some cooling ones were (probably) reheated. Astronomers saw the back of the Sun (which is also made of baryons), a possible solution to the problem of ejection of material by Type II supernovae (in which neutrinos push out baryons), the production of R Coronae Borealis stars (previously-owned baryons), and perhaps found the missing satellite galaxies (whose failing is that they have no baryons). A few questions were left unanswered for next year, and an attempt is made to discuss these as well.

show abstract

“…The observational evidence (as illustrated in figure 2) reveals that there is a great deal of dynamical activity within the hypothesized Vulcanoid zone (recall figure 1) -comets, as the SOHO coronagraph data indicates, continuously passing through the region on an almost daily basis [53]. The Vulcanoid zone is not only dynamically active it is also a region where any passing cometary nuclei will be placed under considerable tidal and thermal stress.…”

Section: Discussionmentioning

confidence: 94%

Vulcanoid Asteroids and Sun-Grazing Comets – Past Encounters and Possible Outcomes

Beech

Peltier

2015

AJAA

View full text Add to dashboard Cite

Abstract:The region between 0.07 to 0.25 au from the Sun is regularly crossed by sungrazing and small perihelion distance periodic comets. This zone also supports stable orbits that may be occupied by Vulcanoid asteroids. In this article we review the circumstances associated with those comets known to have passed through the putative Vulcanoid region, and we review the various histories associated with a sub-group of these comets that have been observed to displayed anomalous behaviors shortly before or after perihelion passage. In all 406 known comets are found to have passed through the Vulcanoid zone; the earliest recorded comet to do so being C/400 F1, with comet C/2008 J13 (SOHO) being the last in the data set used (complete to 2014). Only two of these comets, however, are known to be short period comets, C/1917 F1 Mellish and 96P / Machholz 1, with the majority being sungrazing comets moving along parabolic orbits. We examine the case history of comet C/1917 F1 Mellish in some detail since numerical simulations suggest that over the past ~ 40 thousand years it has regularly passed through the Vulcanoid zone. Additionally, this particular comet is linked to the December Monocerotid meteor shower, which is known to have produced a series of very bright fireball displays in the 11 th Century. An extremely small impact probability of order 10 -19 per perihelion passage with a Vulcanoid of diameter 1 km or larger is determined for comet Mellish, and we conclude that the ancient fireball display is not likely associated with a Vulcanoid collision. Indeed, while we find no evidence to indicate that any historical collisions between a cometary nucleus and a Vulcanoid have occurred, this result, we suggest, does not automatically mean that no Vulcanoids exist at the present time, or that collisions have not taken place in the past. Likewise, these results do not rule out the possibility of collisions being observable at future times. As ever, since first being hypothesized, if they exist at all, the Vulcanoid asteroids remain elusive.

show abstract

Statistical Investigation and Modeling of Sungrazing Comets Discovered with theSolar and Heliospheric Observatory

Cited by 56 publications

References 37 publications

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

Astrophysics in 2002

Vulcanoid Asteroids and Sun-Grazing Comets – Past Encounters and Possible Outcomes

Contact Info

Product

Resources

About