The 2009 Apparition of methuselah comet 107P/Wilson–Harrington: A case of comet rejuvenation?

Planetary and Space Science

Perez

2017

Self Cite

From 1996 to 2015 sixteen main belt asteroids were discovered exhibiting cometary activity (less than one per year), all of them during searches at the telescope. In this work we will explore another way to discover them. We reduced 192016 magnitude observations of 165 asteroids of the Themis family, using data from the astrometric-photometric database of the Minor Planet Center, MPCOBS, and measuring the absolute magnitudes from the phase plots. 25 objects of 165 (15.2%), exhibited bumps or enhancements in brightness that might indicate low level cometary activity. Since activity repeats at the same place in different orbits and in many occasions is centered at perihelion, activity might be due to water ice sublimation. As of September 2016, there are 717768 asteroids listed in the Minor Planet files. If we assume that we do not have any false positives and the above percentage can be extrapolated to the whole Main Belt, the number of potentially active asteroid gets to the very large number of ~111.000. This number is much larger than the ones predicted in previous surveys and indicates one of three scenarios: A) there are many false positives in our detections and the real number of active asteroid is much smaller than we found. This would be tantamount to saying that the MPC astrometric-photometric database is only astrometric and not photometric, invalidating absolute magnitude determinations based on this database. B) The location of active asteroids is restricted to the Themis family and an extrapolation to the whole belt is not possible. Or C) there are few false positives in our candidates and the main belt actually contains many low level active asteroids undetected by current surveys. Case C) would imply that the main belt is not a field of bare rocks but a graveyard of extinct comets, changing our current paradigm of the main belt. So it is of the outmost importance to verify observationally our candidates, and determine which of these scenarios is valid.

Section: Failure Of Previous Detection Methodsmentioning

confidence: 99%

“…The candidates to active asteroids presented in this work exhibit low activity that resembles that of comet 107P/Wilson-Harrington, a well-studied and characterized object (Ferrín, 2012). The reduction procedure used in this work is the same used to reduce this comet.…”

Section: Comparison Light Curve: 107p Wilson Harringtonmentioning

confidence: 99%

“Secular light curves of 25 members of the themis family of asteroids, suspected of low level cometary activity”

Planetary and Space Science

Perez

2017

Self Cite

“…Additional comets have been added to the original RR versus ML-AGE diagram (Ferrín et al 2012;2013a) We find that Δr N should be approximately a constant, assuming that the orbit does not change, that there is no change in the active fraction of the nucleus surface, and that the pole orientation remains stationary.…”

Section: The Remaining Returns Vs the Mass Loss Age Diagrammentioning

confidence: 96%

“…The Remaining Returns versus Mass Loss Age diagram (Figure 25) (Ferrín et al, 2012;2013a), is an evolutionary diagram that makes use of the Mass Loss Budget (the total amount of gas and dust expelled by the comet per orbit), and the diameter of the comet. These two parameters have to be calculated in advance to plot a comet on the diagram.…”

Section: The Remaining Returns Vs the Mass Loss Age Diagrammentioning

confidence: 99%

The location of Oort Cloud comets C/2011 L4 Panstarrs and C/2012 S1 ISON on a comet evolutionary diagram

Monthly Notices of the Royal Astronomical Society

2014

Self Cite

We plot the Secular Light Curves (SLCs) of comets C/2011 L4 Panstarrs and C/2012 S1 ISON. The brightness of C/2011 L4 Panstarrs and C/2012 S1 ISON increase steeply after discovery but both decrease in slope sharply at ~4-5 AU, a characteristic of Oort Cloud cometary light curves that we refer to as a Slope Discontinuity Event (SDE). After the SDE, the SLC of C/2011 L4 continues to increase and has a surge near perihelion. The SLC of comet C/2012 S1 ISON on the other hand, is very odd and exhibits a SDE plus a near-standstill after the event. We found five comets with similar behavior: C/1996 Q1 Tabur, C/1999 S4 LINEAR, C/2002 O4 Hönig, C/2010 X1 Elenin and C/2012 T5 Bressi, all of which disintegrated. Thus we predict that comet ISON will disintegrate too. We compiled published production rates of water, dust and CO and used them to calculate the Mass Loss Budget. We use this information for ISON to calculate the diameter and to plot 29 comets in an Evolutionary Diagram that separates comets by class. We find a diameter D = 1030±70 m in excellent agreement with the upper limit found by Delamere et al. (2013), D(mean) < 1126 m. It is evident that the Secular Light Curves, exhibit complexity beyond current scientific understanding. Note: The comet disintegrated as predicted (CBET 3731), while this paper was being refereed.

“…Thus there seems to be an intermediate value at which the coma disappears hidden inside the seeing disk. This quantity is defined as the Threshold Coma Magnitude and its estimated value is TCM = ~3.0±0.2 magnitudes (Ferrín, 2012). The dependence of this value on the FWHM of the seeing disk, has not yet been quantified.…”

Section: Definition Of Threshold Coma Magnitudementioning

confidence: 99%

Secular light curves of NEAs 2201 Oljato, 3200 Phaethon, 99942 Apophis, 162173 Ryugu, 495848 and 6063 Jason

Monthly Notices of the Royal Astronomical Society

Arcila

Saldarriaga

2018

Using the Secular Light Curve (SLC) formalism (Ferrín, 2010a; PSS, 58, 365-391), we searched for cometary activity of six NEAS: 2201 Oljato. The SLC exhibits significant cometary activity and evidence of an eclipse. 3200 Phaethon. Is the parent of the Geminid meteor stream and exhibited a faint tail at perihelion in several oppositions. The SLC fails to show cometary activity using a 1995 to 2017 data set, suggesting that we are in the presence of a dormant cometary nucleus. 99942 Apophis. This SLC does not shows evidence of cometary activity, however it shows evidence of an eclipse. The evidence of a double nature is confirmed with Goldstone and Arecibo radar observations. 162173 Ryugu. This NEA is the target of the Hayabusa 2 spacecraft mission. The SLC exhibits an enhancement consistent with cometary activity. It may be possible to confirm or deny this activity by the end of the mission. 495848= 2002 QD7. This NEA shows deviations from a flat distribution near perihelion in 2007 and 2017. However our own observations in 2018 show a bare nucleus, from which we obtain an absolute nuclear magnitude mV(nucleus) = 18.32±0.03 (using pV=0.04). The equivalent diameter is D=1.43±0.10 km. 6063 Jason. The SLC of this NEA exhibits low level cometary activity centred at perihelion. The fact that a cursory search for low level active comets among NEAs has uncovered four positive objects out of 6, hints that many more faint comets should exist as yet undetected.