Low thermal conductivity of the superfast rotator (499998) 2011 PT

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F21%3A10438677" target="_blank" >RIV/00216208:11320/21:10438677 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=o94czJm31p" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=o94czJm31p</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202039628" target="_blank" >10.1051/0004-6361/202039628</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Low thermal conductivity of the superfast rotator (499998) 2011 PT

Popis výsledku v původním jazyce

Context. Asteroids with a diameter of up to a few dozen meters may spin very fast and complete an entire rotation within a few minutes. These small and fast-rotating bodies are thought to be monolithic objects because the gravitational force due to their small size is not strong enough to counteract the strong centripetal force caused by the fast rotation. This argument means that the rubble-pile structure is not feasible for these objects. Additionally, it is not clear whether the fast spin prevents dust and small particles (regolith) from being kept on their surface.Aims. We develop a model for constraining the thermal conductivity of the surface of the small, fast-rotating near-Earth asteroids. This model may suggest whether regolith is likely present on these objects.Methods. Our approach is based on the comparison of the measured Yarkovsky drift and a predicted value using a theoretical model that depends on the orbital, physical and thermal parameters of the object. The necessary parameters are either deduced from statistical distribution derived for near-Earth asteroids population or determined from observations with associated uncertainty. With this information, we performed Monte Carlo simulations and produced a probability density distribution for the thermal conductivity.Results. Applying our model to the superfast rotator asteroid (499998) 2011 PT, we find that the measured Yarkovsky drift can only be achieved when the thermal conductivity K of the surface is low. The resulting probability density function for the conductivity is bimodal, with two most likely values being around 0.0001 and 0.005 W m(-1) K-1. Based on this, we find that the probability that K is lower than 0.1 W m(-1) K-1 is at least 95%. This low thermal conductivity might indicate that the surface of 2011 PT is covered with a thermal insulating layer, composed of a regolith-like material similar to lunar dust.

Název v anglickém jazyce

Low thermal conductivity of the superfast rotator (499998) 2011 PT

Popis výsledku anglicky

Context. Asteroids with a diameter of up to a few dozen meters may spin very fast and complete an entire rotation within a few minutes. These small and fast-rotating bodies are thought to be monolithic objects because the gravitational force due to their small size is not strong enough to counteract the strong centripetal force caused by the fast rotation. This argument means that the rubble-pile structure is not feasible for these objects. Additionally, it is not clear whether the fast spin prevents dust and small particles (regolith) from being kept on their surface.Aims. We develop a model for constraining the thermal conductivity of the surface of the small, fast-rotating near-Earth asteroids. This model may suggest whether regolith is likely present on these objects.Methods. Our approach is based on the comparison of the measured Yarkovsky drift and a predicted value using a theoretical model that depends on the orbital, physical and thermal parameters of the object. The necessary parameters are either deduced from statistical distribution derived for near-Earth asteroids population or determined from observations with associated uncertainty. With this information, we performed Monte Carlo simulations and produced a probability density distribution for the thermal conductivity.Results. Applying our model to the superfast rotator asteroid (499998) 2011 PT, we find that the measured Yarkovsky drift can only be achieved when the thermal conductivity K of the surface is low. The resulting probability density function for the conductivity is bimodal, with two most likely values being around 0.0001 and 0.005 W m(-1) K-1. Based on this, we find that the probability that K is lower than 0.1 W m(-1) K-1 is at least 95%. This low thermal conductivity might indicate that the surface of 2011 PT is covered with a thermal insulating layer, composed of a regolith-like material similar to lunar dust.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA18-06083S" target="_blank" >GA18-06083S: Vývoj pevných těles v protoplanetárních discích a během kolizí</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astronomy &amp; Astrophysics

ISSN

0004-6361

e-ISSN

—

Svazek periodika

647

Číslo periodika v rámci svazku

březen

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

12

Strana od-do

A61

Kód UT WoS článku

000627401500003

EID výsledku v databázi Scopus

2-s2.0-85102351047