Main Belt asteroid as a Possible Younger Dryas impactor

Usatov, Maxim

doi:10.1002/asna.202013817

Cited by 3 publications

(2 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…-candidate PAH galaxies from the IRAC We then took advantage of the expected blue optical colors and faint magnitudes of extragalactic sources to reclassify some sources marked as possible galaxies as stars with a disk. We first used the catalogs published by Brescia et al (2015) and Usatov (2018) to define a locus populated by extragalactic sources in the following diagrams: r vs. r − i, g vs. g − r, and r vs. g − r (both VPHAS and Pan-STARRS, see Fig. D.2).…”

Section: Candidate Extragalactic Sourcesmentioning

confidence: 99%

Dispersal timescale of protoplanetary disks in the low-metallicity young cluster Dolidze 25

Guarcello

Biazzo

Drake

et al. 2021

A&A

View full text Add to dashboard Cite

Context. The dispersal of protoplanetary disks sets the timescale that is available for planets to assemble, and thus it is one of the fundamental parameters in theories of planetary formation. Disk dispersal is determined by several properties of the central star, the disk itself, and the surrounding environment. In particular, the metallicity of disks may affect their evolution, but controversial results have been published so far: disks in low-metallicity clusters appear to disperse rapidly, while some evidence supports the existence of accreting disks that are several million years old in the Magellanic Clouds. Aims. We study the dispersal timescale of disks in Dolidze 25, the young cluster in the proximity of the Sun with the lowest metallicity, to understand whether disk evolution is affected by the low metallicity of the cluster. Methods. We analyzed Chandra ACIS-I observations of the cluster and combined the resulting source catalog with existing optical and infrared catalogs of the region. We selected the disk-bearing population in a circular region with a diameter of 1° centered on Dolidze 25 from criteria based on infrared colors, and we selected the disk-less population within a smaller central region from the X-ray sources with O infrared counterparts. In both cases, criteria were applied to discard contaminating sources in the foreground or background. We derived stellar parameters from isochrones that were fit to color-magnitude diagrams. Results. We derived a disk fraction of ∼34% and a median age of the cluster of 1.2 Myr. To minimize the effect of incompleteness and spatial inhomogeneity in the list of members, we restricted this calculation to stars in a magnitude range within which our selection of cluster members is fairly complete. We also adopted different cuts in stellar masses. When we compare this estimate with existing estimates of the disk fraction of clusters younger than 10 Myr, the disk fraction of Dolidze 25 appears to be lower than what is expected based on its age alone. Conclusions. Even though our results are not conclusive given the intrinsic uncertainty on stellar ages estimated from isochrone fitting to color-magnitude diagrams, we suggest that disk evolution in Dolidze 25 may be affected by the environment. Given the poor O-star population and low stellar density of the cluster, it is more likely that the disk dispersal timescale is dictated more by the low metallicity of the cluster than by external photoevaporation or dynamical encounters.

show abstract

Section: Candidate Extragalactic Sourcesmentioning

confidence: 99%

Dispersal timescale of protoplanetary disks in the low-metallicity young cluster Dolidze 25

Guarcello

Biazzo

Drake

et al. 2021

A&A

View full text Add to dashboard Cite

show abstract

“…5 and Table 4 (inclusive) provide new details. As well, main belt asteroids that may provide a possible YD impactor (Usatov, 2020) have yet to be identi ed. As noted by Napier (2019), Earth's 'encounter with Encke would take the form of an intense meteor hurricane lasting a few days, putting enough dust in the mesosphere to block sunlight for settling time of a few years along with enough reballs to create a global wild re (documented by Wolbach et al, 2018a, b).…”

Section: Cosmic Theorymentioning

confidence: 99%

The Encke Comet Impact/Airburst and the Younger Dryas Boundary: Testing the Impossible Hypothesis (YDIH)

Mahaney

Somelar

2023

Preprint

View full text Add to dashboard Cite

Many have tagged the Younger Dryas Impact Hypothesis, (YDIH) an ethereal expression to explain the Younger Dryas (YD) climatic reversal, namely the Younger Dryas Boundary (YDB), a theory, deniers state, lacking convincing evidence in support. The core of the hypothesis lies squarely on anti-uniformitarianism, that is, uniform processes moving uniformly with no room for catastrophic events, specifically cosmic catastrophic forces. Beyond philosophically based aversion to the YDIH, specific criticism comes from megafauna and archaeologic corners, related to the near coeval disappearance of specific Late Pleistocene species on the one hand, and relation to disruption and temporary disappearance of the Clovis people on the other. Coupled to all this, breakup of the Laurentide Ice Sheet (LIS) and resultant Lake Agassiz-Mackenzie River floods, disrupting the thermohaline circulation of the North Atlantic, all meltwater induced marine coupled atmospheric cooling is at the heart of the Late Glacial/Younger Dryas transition. In short, deniers of the cosmic link—the black mat----use geohydrologic explanations to explain the foremost climatic reversal of the Late Pleistocene. The geologic paradigm, firmly in place with meltwater release into the Atlantic in tow, attention slowly drifted to explanation of an innocuous looking, thin (~ 1–2 cm), black sediment bed found in lacustrine and fluvial deposits of the American southwest, and other places. Thus, with thin dark beds of Gubbio in mind, the quest to explain black mat (BM) beds took on a cosmic aspect, one with growing, supporting evidence on several continents. The impossible hypothesis, now the probable explanation of the YD climatic reversal, is at center stage, set at 12.8 ka, with a burgeoning corpus of undeniable evidence its cornerstone. It is this undeniable evidence that is the subject of this paper.

show abstract

The Encke comet impact/airburst and the Younger Dryas Boundary: Testing the impossible hypothesis (YDIH)

Mahaney,

Somelar

2024

logos

View full text Add to dashboard Cite

Many have tagged the Younger Dryas Impact Hypothesis (YDIH), a supposition, lacking convincing evidence in support. The core of criticism lies squarely on uniformitarianism, that is, uniform processes moving uniformly with no room for catastrophic events, specifically cosmic catastrophic forces. Beyond philosophically based aversion to the YDIH, specific criticism comes from megafauna and archaeologic corners, related to the near coeval disappearance of specific Late Pleistocene species on the one hand, and relation to disruption and temporary disappearance of the Clovis people et al. on the other. The Younger Dryas geologic paradigm, originally in place with meltwater release into the Atlantic in tow, attention slowly drifted to explanation of an innocuous looking, thin (~1-3 cm), black sediment bed found in lacustrine and fluvial deposits of the American southwest, and other intercontinental places. Thus, with thin dark beds of Gubbio in mind, the quest to explain black mat (BM) beds took on a cosmic aspect, one with growing, supporting evidence on several continents. The impossible hypothesis, now the probable explanation of the Younger Dryas climatic reversal, is at center stage, set at 12.8 ka, with a burgeoning corpus of evidence its cornerstone.

show abstract

Main Belt asteroid as a Possible Younger Dryas impactor

Cited by 3 publications

References 75 publications

Dispersal timescale of protoplanetary disks in the low-metallicity young cluster Dolidze 25

Dispersal timescale of protoplanetary disks in the low-metallicity young cluster Dolidze 25

The Encke Comet Impact/Airburst and the Younger Dryas Boundary: Testing the Impossible Hypothesis (YDIH)

The Encke comet impact/airburst and the Younger Dryas Boundary: Testing the impossible hypothesis (YDIH)

Contact Info

Product

Resources

About