Activity on the surface of the nucleus of comet 46P/Wirtanen

Groussin, O.; Lamy, Philippe

doi:10.1051/0004-6361:20031496

Cited by 46 publications

(43 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These values can be derived if other data are available, such as gas production rate observations (Bertaux et al 1999), which would directly constrain the dust to gas ratio. It should be noted that a more recent estimate of the icy fraction f of up to 15%, has been made by Groussin and Lamy (2003), which is more consistent with our work. If the active fraction (g) were increased to 100 % as measured by Rickman and Jorda the dust to gas ratio would have to be << 1.…”

Section: P/wirtanensupporting

confidence: 92%

Perceptual Experience

2014

Cognitive Neuroscience of Human Systems

View full text Add to dashboard Cite

Inverse coma and tail modelling of comets based on the method developed by Finson & Probstein (1968) is commonly used to analyse cometary coma images. Models of this type often contain a large number of assumptions that may not be constrained unless wide temporal or spectral coverage is available and the comets are bright and at relatively small geocentric distance. They are used to predict physical parameters, such as the mass distribution of the dust, but rarely give assessments of the accuracy of the estimate. A three-dimensional cometary dust coma model in the collisionless regime has been developed to allow the effectiveness of such models to constrain dust coma properties to be tested. The model is capable of simulating the coma morphology for the following input parameters: the comet nucleus shape, size, rotation, emission function (including active fraction and jets), grain velocity distribution (and dispersion), size distribution, dust production rate, grain material and light scattering from the cometary dust.Characterisation of the model demonstrates that the mass distribution cannot be well constrained as is often assumed; the cumulative mass distribution index α can only be constrained to within ± 0.15. The model is highly sensitive to the input grain terminal velocity distribution so model input can be tested with a large degree of confidence. Complex secondary parameters such as jets, rotation and grain composition all have an effect on the structure of the coma in similar ways, so unique solutions for these parameters cannot be derived from a single optical image alone. Multiple images at a variety of geometries close in time can help constrain these effects.The model has been applied to photometric observations of comets 126P/IRAS and 46P/Wirtanen to constrain a number of physical properties including the dust production rate and mass distribution index. The derived dust production rate (Q dust ) for 46P/Wirtanen was 3 +7 / -1.5 kg s -1 at a pre-perihelion heliocentric distance of 1.8 AU, and for P/IRAS was 50 +100 / -20 kg s -1 at a preperihelion heliocentric distance of 1.7 AU; both comets exhibited a mass distribution index α= 0.8 ± 0.15.

show abstract

Section: P/wirtanensupporting

confidence: 92%

Perceptual Experience

2014

Cognitive Neuroscience of Human Systems

View full text Add to dashboard Cite

show abstract

“…According to the scenario of the evolution of the surface of 46P/Wirtanen by Groussin and Lamy (2003), such a rubble crust was likely present at the time of our HST observations (Lamy et al, 1998a). Despite these difficulties, (areas of free-sublimating ice required by the measured OH production rates) to the surface areas of spherical nuclei using the effective radii tabulated by Lamy et al (2004).…”

Section: The Color-active Fraction Relationship For Cometary Nucleimentioning

confidence: 78%

“…This idea was further reinforced by the in-situ observation of 19P/Borrelly in 2001, which shows the same properties. As new size determinations are available as well as extended measurements of water production rates (e.g., A 'Hearn et al 1995), it now appears that cometary nuclei, in particular the sub-kilometer ones, may have very large active fractions, in fact as much as 100% of their surface such as 46P/Wirtanen (Groussin and Lamy, 2003). The reality is certainly a spectrum of very different situations, from nuclei still having preserved much of their original (irradiation ?)…”

Section: The Color-active Fraction Relationship For Cometary Nucleimentioning

confidence: 99%

The colors of cometary nuclei—Comparison with other primitive bodies of the Solar System and implications for their origin

Lamy

Tóth

2009

Icarus

Self Cite

View full text Add to dashboard Cite

To cite this version:P. Lamy, I. Toth. The colors of cometary nuclei -Comparison with other primitive bodies of the Solar system and implications for their origin. Icarus, Elsevier, 2009, 201 (2) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. and Centaurs II with (B − R) < 1.4. Centaurs I could be composed of TNOs (prominently CKBO-LI) and ultra red objects from a yet unstudied family. Centaurs II could consist in a population of evolved objects which have already visited the inner solar system, and which has been scattered back beyond Jupiter. The diversity of colors of the ECs, in particular the existence of very red objects, is consistent with an origin in the Kuiper belt. Candidate dead comets represent an ultimate state of evolution as they conspicuously appear more evolved than the Trojans and Centaurs II. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT

show abstract

“…Their fall is guided by the gravitational attraction and is then oriented toward the nearest gravitational low. However, this transport mechanism is limited to boulders smaller than the meter scale because larger boulders are too big to be lifted (Groussin & Lamy 2003;Kelley et al 2013;Pajola et al 2015;Thomas et al 2015a). Since many boulders larger than one meter are visible on Imhotep, including some on smooth terrains, air-fall deposits cannot account for all of them.…”

Section: Smooth Terrainsmentioning

confidence: 99%

Geomorphology of the Imhotep region on comet 67P/Churyumov-Gerasimenko from OSIRIS observations

Auger

Groussin

Jordá

et al. 2015

A&A

Self Cite

View full text Add to dashboard Cite

Context. Since August 2014, the OSIRIS Narrow Angle Camera (NAC) onboard the Rosetta spacecraft has acquired high spatial resolution images of the nucleus of comet 67P/Churyumov-Gerasimenko, down to the decimeter scale. This paper focuses on the Imhotep region, located on the largest lobe of the nucleus, near the equator. Aims. We map, inventory, and describe the geomorphology of the Imhotep region. We propose and discuss some processes to explain the formation and ongoing evolution of this region. Methods. We used OSIRIS NAC images, gravitational heights and slopes, and digital terrain models to map and measure the morphologies of Imhotep. Results. The Imhotep region presents a wide variety of terrains and morphologies: smooth and rocky terrains, bright areas, linear features, roundish features, and boulders. Gravity processes such as mass wasting and collapse play a significant role in the geomorphological evolution of this region. Cometary processes initiate erosion and are responsible for the formation of degassing conduits that are revealed by elevated roundish features on the surface. We also propose a scenario for the formation and evolution of the Imhotep region; this implies the presence of large primordial voids inside the nucleus, resulting from its formation process.

show abstract

Activity on the surface of the nucleus of comet 46P/Wirtanen

Cited by 46 publications

References 42 publications

Perceptual Experience

Perceptual Experience

The colors of cometary nuclei—Comparison with other primitive bodies of the Solar System and implications for their origin

Geomorphology of the Imhotep region on comet 67P/Churyumov-Gerasimenko from OSIRIS observations

Contact Info

Product

Resources

About