Sona Hosseini, Walter Harris, Jason Corliss

Author Affiliations +

Proceedings Volume 8446, Ground-based and Airborne Instrumentation for Astronomy IV; 84464K (2012)

Event: SPIE Astronomical Telescopes + Instrumentation, 2012, Amsterdam, Netherlands


We describe first results from a new instrument-telescope configuration that combines all of the capabilities necessary to obtain high resolving power visible band spectra of diffuse targets from small aperture telescopes where significant observing time can be obtained. This instrument –Khayyam- is a tunable all-reflective spatial heterodyne spectrometer (SHS) that is mounted to a fixed focal plane shared by the 0.6m Coude auxiliary telescope and the 3m Shane telescope on Mt. Hamilton. Khayyam has an up to 78 arcmin input field of view, resolving power up to 176000, and a tunable bandpass from 350-700 nm. It is being field tested for initial use to study spatially extended solar system targets where high resolving power is necessary to separate multimodal signals, crowded molecular bands, and to sample low velocities (<10 km/s) and rapid temporal cadence is necessary to track physical evolution. Two of the best comet targets during next year is comet C/2011 L4 (PanSTARRS), and C/2011 F1 (LINEAR). Our goal is to sequentially measure isotopic ratios of 14N:15N and 12C:13C in CN, along with the production rate and the production rate ratios of varies daughter species, particularly C2, C3, NH2, OI, and CN, as a function of heliocentric distance and time.

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Sona Hosseini, Walter Harris, and Jason Corliss "Khayyam: a tunable spatial heterodyne spectrometer for observing diffuse emission line targets", Proc. SPIE 8446, Ground-based and Airborne Instrumentation for Astronomy IV, 84464K (5 October 2012);


Farah Alibay Philip Fernandes Ryan McGranaghan Jason Leonard Ryan Clegg Patricia Craig


Visited only by Voyager 2 in 1989, Neptune and its moon Triton hold important clues to the formation and evolution of the solar system and exoplanetary systems. Neptune-sized planets are the most commonly discovered exoplanets to date. Neptune, an ice giant, is theorized to have migrated from its formation location in the early solar system. This migration affects the expected interior structure, composition, and dynamical evolution of the planet. Triton is conjectured to be a heavily-processed, captured Kuiper Belt Object (KBO), a remnant from the early solar nebula and unique in our solar system. Triton may possess a subsurface aqueous ocean, making it an important astrobiological target. The 2013-2022 Planetary Science Decadal Survey [1] identified a number of high priority science goals for the Neptunian system, including understanding the structure, composition, and dynamics of Neptune's atmosphere and magnetosphere, as well as surveying the surface of Triton. Following these guidelines, we present a low cost flyby mission concept to Neptune and Triton: TRIDENT (Taking Remote and In-situ Data to Explore Neptune and Triton). TRIDENT would carry six instruments and a government furnished atmospheric probe and would provide significant improvements over the scientific measurements undertaken by Voyager 2. In this paper, we first provide a detailed overview of the science questions pertaining to Neptune and Triton and of the science investigations necessary to elucidate them. We then present the design of TRIDENT's instrument suite, the trajectory and the spacecraft, as well as the motivation behind each of our choices. In particular, we demonstrate that, for a mission launched on an Atlas V 551, a Neptune orbiter mission would be infeasible with current technology levels without the use of aerocapture. We therefore present a flyby mission concept with a cost lower than FY2015 $1.5B. We also show that the proposed mission has low risk and significant margin and tha...

Published in: 2014 IEEE Aerospace Conference

Date of Conference: 1-8 March 2014

Date Added to IEEE Xplore: 19 June 2014

 ISBN Information:

Print ISSN: 1095-323X

INSPEC Accession Number: 14394262

DOI: 10.1109/AERO.2014.6836294

Publisher: IEEE

Conference Location: Big Sky, MT, USA

Lotfi Ben-Jaffel1,3and S. Sona Hosseini21UPMC Univ Paris 06, UMR7095, Institut d’Astrophysique de Paris, F-75014, Paris, France;bjaffel@iap.fr2Department of Applied Science, UC Davis, One shields avenue, Davis, CA 95616, USA;sshosseini@ucdavis.eduReceived 2009 August 31; accepted 2009 December 7; published 2010 January 13


Stellar irradiation and particle forcing strongly affect the immediate environment of extrasolar giant planets orbitingnear their parent stars. However, it is not clear how the energy is deposited over the planetary atmosphere, norhow the momentum and energy spaces of the different species that populate the system are modified. Here, we usefar-ultraviolet emission spectra from HD209458 in the wavelength range (1180–1710) Å to bring new insight to thecomposition and energetic processes in play in the gas nebula around the transiting planetary companion. In thatframe, we consider up-to-date atmospheric models of the giant exoplanet where we implement non-thermal linebroadening to simulate the impact on the transit absorption of superthermal atoms (Hi,Oi, and Cii) populating theupper layers of the nebula. Our sensitivity study shows that for all existing models, a significant line broadening isrequired for Oiand probably for Ciilines in order to fit the observed transit absorptions. In that frame, we showthat Oiand Ciiare preferentially heated compared to the background gas with effective temperatures as large asTOi/TB∼10 for OiandTCii/TB∼5forCii. By contrast, the situation is much less clear for Hibecause severalmodels could fit the Lyαobservations including either thermal Hiin an atmosphere that has a dayside verticalcolumn [Hi]∼1.05×1021cm−2, or a less extended thermal atmosphere but with hot Hiatoms populating theupper layers of the nebula. If the energetic Hiatoms are either of stellar origin or populations lost from the planetand energized in the outer layers of the nebula, our finding is that most models should converge toward one hotpopulation that has an Hivertical column in the range [Hi]hot∼(2–4)×1013cm−2and an effective temperaturein the rangeTHi∼(1–1.3)×106K, but with a bulk velocity that should be rather slow.Key words:line: formation – line: profiles – planetary systems – radiation mechanisms: non-thermal – stars:individual (HD209458) – ultraviolet: stars

Amanda R. Hendrix,Terry A. Hurford,Laura M. Barge,Michael T. Bland,Jeff S. Bowman,William Brinckerhoff,BonnieJ.Buratti,MorganL.Cable,JulieCastilloRogez,GeoffreyC.Collins,SerinaDiniega,ChristopherR.German,AlexanderG.Hayes,ToriHoehler,SonaHosseini,CarlyJ.A.Howett,AlfredS.McEwen,CatherineD.Neish,MarcNeveu,TomA.Nordheim,G.WesleyPatterson,D.Alexatthoff,CynthiaPhillips,Alysa Rhoden,Britney E. Schmidt,KelsiN.Singer,Jason M. Soderblom, andSteven D. Vance


In this article, we summarize the work of the NASA Outer Planets Assessment Group (OPAG) Roadmaps to Ocean Worlds (ROW) group. The aim of this group is to assemble the scientific framework that will guide the exploration of ocean worlds, and to identify and prioritize science objectives for ocean worlds over the next several decades. The overarching goal of an Ocean Worlds exploration program as defined by ROW is to “identify ocean worlds, characterize their oceans, evaluate their habitability, search for life, and ultimately understand any life we find.” The ROW team supports the creation of an exploration program that studies the full spectrum of ocean worlds, that is, not just the exploration of known ocean worlds such as Europa but candidate ocean worlds such as Triton as well. The ROW team finds that the confirmed ocean worlds Enceladus, Titan, and Europa are the highest priority bodies to target in the near term to address ROW goals. Triton is the highest priority candidate ocean world to target in the near term. A major finding of this study is that, to map out a coherent Ocean Worlds Program, significant input is required from studies here on Earth; rigorous Research and Analysis studies are called for to enable some future ocean worlds missions to be thoughtfully planned and undertaken. A second finding is that progress needs to be made in the area of collaborations between Earth ocean scientists and extraterrestrial ocean