Icarus, Год журнала: 2024, Номер 421, С. 116227 - 116227
Опубликована: Июль 30, 2024
Язык: Английский
Monthly Notices of the Royal Astronomical Society, Год журнала: 2025, Номер 538(1), С. 470 - 479
Опубликована: Фев. 5, 2025
ABSTRACT During its most recent return, comet 12P/Pons–Brooks experienced 14 well-documented outbursts, observed between 2023 June 13 and 2024 April, at heliocentric distances ranging from $4.26\,$ to $0.85\,$ au. After perihelion, two additional outbursts were in summer 2024, of $1.20\,$ $2.26\,$ Using observational data, we developed a numerical model estimate the mass ejected during these events, focusing on sublimation ice through porous cometary nucleus. The key factors affecting estimates are outburst amplitude active surface area both quiet phases. Pogson’s law was used express magnitude, incorporating scattering cross-sections agglomerates. iteratively determined considering various types (H$_{2}$O CO$_{2}$) controlling activity. Our results indicate that ranged 10$^{10}$ 10$^{13}$ kg. findings highlight significant role morphology thermodynamic conditions providing insights into mechanisms driving phenomena their implications for evolution dust trail formation. Based analysis propose six-level classification scheme outbursts.
Язык: Английский
Процитировано
1
Icarus, Год журнала: 2024, Номер 416, С. 116087 - 116087
Опубликована: Апрель 17, 2024
The paper presents new experimental results of measurements the hemispherical albedo a potential comet analogue and an analysis its influence on change in cometary brightness. Measurements spectral properties tested analogues were performed using Cary 5000 spectrometer wavelength range from 200 to 2500 nm. Two samples used as dust analogue: mixture sand ash (sample A) charcoal B), respectively. obtained values for ranged 1.20% 32.25%. In particular, sample B, are comparable actual reflectance 67P. Based samples, thermodynamic model activity was developed used, among others, calculate power absorbed by sublimation flux occurring through porous structure fine-grained present surface. brightness during outburst, upper limit which equal 5.36 magnitude.
Язык: Английский
Процитировано
2
Astronomy and Astrophysics, Год журнала: 2024, Номер 686, С. A248 - A248
Опубликована: Май 1, 2024
The paper presents the results of spectroscopic measurements for selected dust analogues, based on which change in cometary brightness was determined. In first part article, we present laboratory hemispherical albedo analogues using a Cary 5000 spectrometer with an integrating sphere. case this system and tested samples, obtained values ranged from 0.35 ± 0.07% to 41.58 0.07%. measurement were used determine bolometric geometric albedo. For analogue consisting charcoal, Bond equal A B (charcoal) = 2.15%, whereas p v 6.76%. second analytical method allowing us calculate amplitude during outburst. calculations show that upper value is 6.5 magnitudes, within medium range Calculations have shown as increases given agglomerate porosity, temperature decreases, determines smaller sublimation flux, translates into larger brightness.
Язык: Английский
Процитировано
2
Monthly Notices of the Royal Astronomical Society, Год журнала: 2023, Номер 521(1), С. 1570 - 1577
Опубликована: Март 1, 2023
ABSTRACT The paper discusses selected mechanisms that can significantly contribute to the formation of dune structures on surface comets. In these considerations, related dynamics dust nucleus were taken into account. first step, maximum dimensions particles be entrained cometary atmosphere as a result local sublimation water ice have been determined. Then, three processes movement comet considered, such migration, landslide turn avalanche, and fluidization unstable dust. thermodynamic process responsible for initiating is sublimation. These cause move by liquefaction given layer. Due complex regular structure nucleus, moving suddenly stop flowing. For individual structures, angular width particle, particle mobility coefficient, static pressure It should noted in those parts are illuminated Sun, occur almost simultaneously, leading piling up particles.
Язык: Английский
Процитировано
5
Icarus, Год журнала: 2022, Номер 388, С. 115209 - 115209
Опубликована: Авг. 15, 2022
The paper presents experimental studies on the degassing of porous ice and mixtures sand in a vacuum. study aims to find relationship between surface recession rate subsurface temperature gradient as well granulation composition material. We propose an empirical equation tested samples with mass fraction non-volatile material range 0–3.65. Based proposed equation, calculations were carried out, which indicate possibility landslides inclined areas comet 9P/Tempel 1.
Язык: Английский
Процитировано
8
Icarus, Год журнала: 2023, Номер 398, С. 115518 - 115518
Опубликована: Март 15, 2023
Язык: Английский
Процитировано
4
Monthly Notices of the Royal Astronomical Society, Год журнала: 2023, Номер 527(3), С. 7613 - 7625
Опубликована: Ноя. 27, 2023
ABSTRACT This paper presents a new approach to determining the dimensions of particles that can be lifted coma by sublimation flux water ice. Due diverse colour cometary surfaces, in presented calculations we take into account influence reflectance coefficient (hemispherical albedo) on size from surface nucleus. A Cary 5000 spectrometer was used measure hemispherical albedo. Spectroscopic measurements dust consisted pure silicate or were mixture and organic compounds such as charcoal, soot, ash. In addition, these admixtures acted means darkening tested sample. Depending sample wavelength, measured value albedo oscillated range 4.93 per cent 48.65 cent. thermodynamic model matter emission developed based results measurements. The performed numerical simulations show temperature decreases with increase albedo, which translates dynamics dust-ice present Taking extreme values differences carried away nucleus are order centimeters.
Язык: Английский
Процитировано
4
Icarus, Год журнала: 2023, Номер 411, С. 115937 - 115937
Опубликована: Дек. 30, 2023
Язык: Английский
Процитировано
4
Monthly Notices of the Royal Astronomical Society, Год журнала: 2022, Номер 517(4), С. 4950 - 4958
Опубликована: Окт. 14, 2022
ABSTRACT The paper presents a new approach to determining the change in brightness of comet during an outburst. It was investigated how porosity dust particle translates into increase has been shown that greater given particle, scattering efficiency, which directly amplitude cometary brightness. In case dense aggregates with ψ = 0.05, rate varies from −0.74 −4.24 mag. porous agglomerates, is range 0.30 0.90, ranges −0.91 −6.66
Язык: Английский
Процитировано
7
Icarus, Год журнала: 2023, Номер 410, С. 115861 - 115861
Опубликована: Ноя. 11, 2023
In our paper we presented the results of laboratory experiments dealing with formation and sliding desiccated nonvolatile granular material down samples potential cometary analogs. The studied were composed porous aggregates containing water ice, quartz sand charcoal. Their surfaces initially free sand. We have found, that under special conditions released due to sublimation ice may almost continuously slide surface leave it compared observations scarps on nucleus comet 67P/Churyumov-Gerasimenko.
Язык: Английский
Процитировано
2