Observational Characterization of Main-belt Comet and Candidate Main-belt Comet Nuclei
The Planetary Science Journal, 2023 We report observations of nine main-belt comets (MBCs) or candidate MBCs, most of which were obtained when the targets were apparently inactive. We find effective nucleus radii (assuming albedos of p _V = 0.05 ± 0.02) of r _n = (0.24 ± 0.05) km for 238P ...
Henry H. Hsieh +11 more
doaj +3 more sources
Low YTHDC1 Expression Upregulates FSCN1 to Promote Nuclear F-Actin Formation and Facilitate Double-strand DNA Breaks Repair in TMZ-Resistant Glioblastoma. [PDF]
Adv Sci (Weinh)This study revealed that low expression of YTHDC1 in TMZ‐resistant GBM cells leads to increased FSCN1 expression, which is suppressed by m6A modification. FSCN1 activates the CDC42/N‐WASP/Arp2/3 axis in the cell nucleus by recruiting the guanine nucleotide exchange factor (GEF) family member FGD1, thereby promoting F‐actin polymerization in the nucleus.
Yang M +9 more
europepmc +2 more sources
Direct Simulation Monte Carlo Modeling of Ammonia in Comet C/2014 Q2 (Lovejoy)
The Astronomical Journal, 2023 Ammonia (NH _3 ), likely the most abundant nitrogen-bearing molecule in cometary ices followed by hydrogen cyanide, is believed to be stored in the nucleus predominantly as a parent ice.
Hideyo Kawakita +7 more
doaj +1 more source
Status of the COMET experiment [PDF]
EPJ Web of Conferences, 2023 The COMET (COherent Muon to Electron Transition) experiment, currently being built in Tokai, Japan, will search for the coherent neutrinoless transition of muons to electrons in the coulomb field of atomic nuclei.
Jansen Andreas
doaj +1 more source
TNO or Comet? The Search for Activity and Characterization of Distant Object 418993 (2009 MS9)
The Planetary Science Journal, 2023 The perihelion of the trans-Neptunian object (TNO) 2009 MS9 brings it close to the distance where some long-period comets are seen to become active.
Erica Bufanda +12 more
doaj +1 more source
On Averaging Eccentric Orbits: Implications for the Long-term Thermal Evolution of Comets
The Astronomical Journal, 2023 One of the common approximations in long-term evolution studies of small bodies is the use of circular orbits averaging the actual eccentric ones, facilitating the coupling of processes with very different timescales, such as the orbital changes and the ...
Anastasios Gkotsinas +2 more
doaj +1 more source
Disintegration of Long-period Comet C/2021 A1 (Leonard)
The Astronomical Journal, 2023 We present imaging observations of the disintegrating long-period comet C/2021 A1 (Leonard). High-resolution observations with the Hubble Space Telescope show no evidence for surviving fragments, and place a 3 σ upper limit on their possible radius of ...
David Jewitt +5 more
doaj +1 more source
The Gateway from Centaurs to Jupiter-family Comets: Thermal and Dynamical Evolution
The Astrophysical Journal, 2023 It was recently proposed that there exists a “gateway” in the orbital parameter space through which Centaurs transition to Jupiter-family comets (JFCs).
Aurélie Guilbert-Lepoutre +3 more
doaj +1 more source
Pits on Jupiter-family Comets and the Age of Cometary Surfaces
The Planetary Science Journal, 2023 Large and deep depressions, also known as pits, are observed at the surface of all Jupiter-family comets (JFCs) imaged by spacecraft missions. They offer the opportunity to glimpse the subsurface characteristics of comet nuclei and study the complex ...
Aurélie Guilbert-Lepoutre +6 more
doaj +1 more source
Comet P/2021 HS (PANSTARRS) and the Challenge of Detecting Low-activity Comets
The Planetary Science Journal, 2023 Jupiter-family comet (JFC) P/2021 HS (PANSTARRS) only exhibits a coma within a few weeks of its perihelion passage at 0.8 au, which is atypical for a comet.
Quanzhi Ye +10 more
doaj +1 more source