Icarus, Год журнала: 2023, Номер 411, С. 115937 - 115937
Опубликована: Дек. 30, 2023
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
Scientific Reports, Год журнала: 2023, Номер 13(1)
Опубликована: Окт. 10, 2023
Abstract The problem of sky pollution with artificial light currently affects practically all branches that are related to the broadly understood environment. This is especially true for astronomical observations. paper presents results measurements surface brightness night city Rzeszów and surrounding area, which were made in 2015, 2018 2021 using photometer Sky Quality Meter (SQM-L). show 2015 was range from 19.20 18.67 mag/arcsec 2 , value oscillated 18.53 16.47 this 17.13 by 15.11 . Translating obtained values on Bortle scale, we can see an increase class VI IX 2021. A similar trend applies neighboring towns, IV VIII also observed. An causes a deterioration or even loss visibility objects sky. comets low-brightness stars. Based measurement results, forecast development prepared study areas until 2025. shows will still have deal Due further projected sky, it should be expected observers small towns experience changes quality over coming years, undoubtedly make observations difficult, particular faint celestial bodies such as comets.
Язык: Английский
Процитировано
5
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