Search Publications
SOHO SWAN Lyα Models Supporting LRO LAMP: 2008–2023
Pryor, Wayne R.; Gladstone, G. Randall; Quémerais, Eric +5 more
The Lunar Reconnaissance Orbiter Lyman-Alpha Mapping Project (LAMP) has been mapping the Moon since its launch in 2009. Faint ultraviolet illumination of the lunar dark side includes light from stars and from hydrogen Lyα emissions, mostly attributed to sunlight scattered by hydrogen atoms near the Sun with a smaller contribution from the whole Ga…
Characterization of the Dust and Sodium Tails of Comet C/2020 F3 (NEOWISE) from Parker Solar Probe and Amateur Observations
Coates, Andrew J.; Afghan, Qasim; Jones, Geraint H. +2 more
Comet C/2020 F3 (NEOWISE) reached perihelion on 2020 July 3 at 0.29 au and exhibited a highly structured dust tail. Using a simplified Finson–Probstein model, structures such as striae, observed in the tail in images obtained by the Parker Solar Probe spacecraft and amateur observers, are characterized in this work and parameterized in terms of du…
Sodium Brightening of (3200) Phaethon near Perihelion
Zhang, Qicheng; Knight, Matthew M.; Battams, Karl +2 more
Sunskirting asteroid (3200) Phaethon has been repeatedly observed in Solar Terrestrial Relations Observatory (STEREO) Heliospheric Imager 1 (HI1) imagery to anomalously brighten and produce an antisunward tail for a few days near each perihelion passage, phenomena previously attributed to the ejection of micron-sized dust grains. Color imaging by …
Surface Properties of Near-Sun Asteroids
Richardson, Derek C.; Sunshine, Jessica M.; Hsieh, Henry H. +8 more
Near-Earth asteroids (NEAs) with small perihelion distances reach subsolar temperatures of ≥1000 K. They are hypothesized to undergo "supercatastrophic" disruption, potentially caused by near-Sun processes such as thermal cracking, spin-up, meteoroid impacts, and subsurface volatile release, all of which are likely to cause surface alteration, whi…
Volatile Composition and Outgassing in C/2018 Y1 (Iwamoto): Extending Limits for High-resolution Infrared Cometary Spectroscopy between 2.8 and 5.0 µm
Vervack, Ronald J., Jr.; Kawakita, Hideyo; DiSanti, Michael A. +7 more
We used the powerful high spectral resolution cross-dispersed facility spectrograph, iSHELL, at the NASA Infrared Telescope Facility (IRTF) to observe C/2018 Y1 (Iwamoto), a long-period comet from the Oort cloud. We report production rates for water and eight other parent molecules (native ices), C2H6, CO, CH4, H
Variable X-Ray Emission of Comet 46P/Wirtanen
Bodewits, Dennis; Christian, Damian J.; Koutroumpa, Dimitra +3 more
In this paper, we present an analysis of X-ray and optical/ultraviolet (UV) data from the favorable (Δ ~ 0.077 au) 2018 apparition of comet 46P/Wirtanen. The comet was observed during three different epochs (before, during, and after perihelion) over a 1.5 month period using the X-Ray Telescope (XRT) and Ultraviolet and Optical Telescope (UVOT) in…
Comet 41P/Tuttle-Giacobini-Kresak, 45P/Honda-Mrkos-Pajdusakova, and 46P/Wirtanen: Water Production Activity over 21 yr with SOHO/SWAN
Bertaux, J. -L.; Combi, M. R.; Quémerais, E. +3 more
In 2017, 2018, and 2019, comets 46P/Wirtanen, 45P/Honda-Mrkos-Pajdusakova, and 41P/Tuttle-Giacobini-Kresak all had perihelion passages. Their hydrogen comae were observed by the Solar Wind ANisotropies (SWAN) all-sky hydrogen Lyα camera on the SOlar and Heliospheric Observer (SOHO) satellite: comet 46P for the fourth time and comets 45P and 41P fo…