Results 91 to 100 of about 32,395 (222)

SPHEREx Pre-perihelion Mapping of H2O, CO2, and CO in Interstellar Object 3I/ATLAS

The Astrophysical Journal Letters
From 2025 August 1 to August 15 UT, the SPHEREx spacecraft observed interstellar object 3I/ATLAS. Using R = 40–130 spectrophotometry at λ = 0.7–5 μ m, lightcurves, spectra, and imaging of 3I were obtained.
Carey M. Lisse, Yoonsoo P. Bach, Brendan P. Crill, Phil M. Korngut, Ari J. Cukierman, Sean A. Bryan, Asantha Cooray, C. Darren Dowell, Michael W. Werner, Joseph L. Hora, Zafar Rustamkulov, Jeong-Eun Lee, Bumhoo Lim, Y. R. Fernandez, Volker Tolls, W. T. Reach, O. Doré, Michael Zemcov, James J. Bock, Yun-Ting Cheng, C. Champagne, Seungwon Choi, M. Connelley, J. P. Emery, Spencer Everett, Andreas L. Faisst, Jooyeon Geem, Howard Hui, Masateru Ishiguro, Sunho Jin, Hangbin Jo, Max Mahlke, Daniel C. Masters, Gary J. Melnick, Chi H. Nguyen, Roberta Paladini, M. L. Sitko, Yujin Yang   +37 more
doaj   +1 more source

A Large Outburst, Coma Asymmetries, and the Color of Comet 243P/NEAT

The Planetary Science Journal
Water ice is a fundamental building material of comets and other bodies in the outer solar system. Yet the properties of cometary water ice are challenging to study, due to its volatility and the typical distances at which comets are observed.
Michael S. P. Kelley, Silvia Protopapa, Dennis Bodewits, Aren N. Heinze, Youssef Moulane, Quanzhi Ye, Bryce Bolin, Simon Conseil, Tony L. Farnham, Lori Feaga, Xing Gao, Chih-Hao Hsia, Emmanuel Jehin, Shrinivas R. Kulkarni, Russ R. Laher, Tim Lister, Frank J. Masci, Josiah Purdum, Bin Yang   +18 more
doaj   +1 more source

The Evolving Activity of the Dynamically Young Comet C/2009 P1 (Garradd)

, 2014
We used the UltraViolet-Optical Telescope on board Swift to observe the dynamically young comet C/2009 P1 (Garradd) from a heliocentric distance of 3.5 AU pre-perihelion until 4.0 AU outbound.
A'Hearn, M. F., Bodewits, D., Farnham, T. L., Feaga, L. M., McKay, A., Schleicher, D. G., Sunshine, J. M   +6 more
core   +1 more source

Dust Production Rates in Jupiter-family Comets: A Two Year Study with ATLAS Photometry

The Planetary Science Journal
Jupiter-family comets (JFCs) exhibit a wide range of activity levels and mass loss over their orbits. We analyzed high-cadence observations of 42 active JFCs with the wide-field Asteroid Terrestrial-impact Last Alert System (ATLAS) in 2020–
A. Fraser Gillan, Alan Fitzsimmons, Larry Denneau, Robert J. Siverd, Ken W. Smith, John L. Tonry, David R. Young   +6 more
doaj   +1 more source

Color gradients in the coma of P/Halley [PDF]

Some important information relevant to the understanding of the gas/dust dynamics near the surface of a comet nucleus concerns knowledge of the grain composition and scattering properties as well as the particle size distribution of dust in the coma ...
Meech, Karen
core   +1 more source

A Portrait throughout Perihelion of the NH2-rich Interstellar Comet 2I/Borisov

The Planetary Science Journal
The interstellar comet 2I/Borisov is the first interstellar object where compositional characterisation was possible throughout its entire perihelion passage.
Sophie E. Deam, Michele T. Bannister, Cyrielle Opitom, Matthew M. Knight, Léa Ferellec, Ryan Ridden-Harper, Darryl Z. Seligman, Alan Fitzsimmons, Aurélie Guilbert-Lepoutre, Emmanuel Jehin, Laurent Jorda, Michael Marsset, Youssef Moulane, Philippe Rousselot, Pierre Vernazza, Bin Yang   +15 more
doaj   +1 more source

Randomization of particle motions and the observed morphology of cometary heads [PDF]

A great diversity is known to exist in the coma morphology of comets. In particular, some comets show much structural detail in their heads (such as jets, halos, fans, plumes, streamers), while others have completely structureless comas.
Sekanina, Zdenek
core   +1 more source

Pre-perihelion Emergence of the CN Gas Coma in 3I/ATLAS Temporally and Spatially Resolved by the 7-dimensional Telescope

The Astrophysical Journal
We present time series medium-band ( R ∼ 20–40) observations of the third interstellar object (ISO) 3I/ATLAS (C/2025 N1) obtained with the 7-Dimensional Telescope, which enabled spatially resolved monitoring of its gas and dust activity from 2025 July to
Gregory S. H. Paek, Myungshin Im, Mankeun Jeong, Hyeonho Choi, Yoonsoo P. Bach, Masateru Ishiguro, Bumhoo Lim, Seo-Won Chang, Ji Hoon Kim, Jooyeon Geem, Willem B. Hoogendam   +10 more
doaj   +1 more source

The footprint of cometary dust analogs: I. Laboratory experiments of low-velocity impacts and comparison with Rosetta data

, 2017
Cometary dust provides a unique window on dust growth mechanisms during the onset of planet formation. Measurements by the Rosetta spacecraft show that the dust in the coma of comet 67P/Churyumov-Gerasimenko has a granular structure at size scales from ...
Bentley, M. S., Blum, J., Dominik, C., Ellerbroek, L. E., Gundlach, B., Hilchenbach, M., John, H., Landeck, A., Mannel, T., Merouane, S., van Veen, H. A.   +10 more
core   +2 more sources

The Extreme Activity in Comet Hale–Bopp (C/1995 O1): Investigations of Extensive Narrowband Photoelectric Photometry

The Planetary Science Journal
Conventional narrowband photoelectric photometry of Comet Hale–Bopp (1995 O1) was obtained on 99 nights from mid-1995 to early-2000, yielding gas and dust production rates over an unprecedented range of time and distance. The appearance of Hale–Bopp (H-B)
David G. Schleicher, Peter V. Birch, Tony L. Farnham, Allison N. Bair   +3 more
doaj   +1 more source