Cometary Science Newsletter

Issue
107
Month
March 2024
Editor
Michael S. P. Kelley (msk@astro.umd.edu)

ESA Archival Research Visitor Programme

Dear Colleagues:

To increase the scientific return from its space science missions, the European Space Agency (ESA) welcomes applications from scientists interested in pursuing research projects based on data publicly available in the ESA Space Science Archives (https://www.cosmos.esa.int/web/esdc).

The ESA Archival Research Visitor Programme is open to scientists, at all career levels, affiliated with institutes in ESA Member States and Collaborating States. Early-career scientists (within 10 years of the PhD) and PhD students are particularly encouraged to apply. We encourage applications from women and minorities. The evaluation process is anonymised to ensure equal opportunities for all applicants.

During their stay, visiting scientists will have access to archives and mission specialists for help with the retrieval, calibration, and analysis of archival data. In principle, all areas of space research covered by ESA science missions can be supported.

Residence lasts typically between one and three months, also distributed over multiple visits. Research projects can be carried out at ESAC (Madrid, Spain) and at ESTEC (Noordwijk, Netherlands). To offset the expenses incurred by visitors, ESA covers travel costs from and to the home institution and provides support for lodging expenses and meals.

Applications received before 1 May 2024 will be considered for visits in autumn and winter 2024/2025.

For further details, including areas of research and contact information, please refer to: https://www.cosmos.esa.int/web/esdc/visitor-programme or write to the programme coordinators at arvp@cosmos.esa.int.

Best regards,
Guido De Marchi

Refereed Articles

Abstracts of articles in press or recently published. Limited to 3000 characters.

Ultraviolet and Infrared Luminescence of Near-Earth Objects

  • Irakli Simonia
  1. Ilia State University

This work deals with a possible ultraviolet and infrared luminescence of the solid substance of the near-Earth objects. In particular, features of the phenomena of photoluminescence and cathodoluminescence of substance of these objects are considered. It is shown that ultraviolet and infrared luminescence of these objects can be revealed by orbital-based instruments. It is demonstrated that detectability of luminescence of Near-Earth Objects opens up the possibilities for determination the physical-chemical properties of their solid substance and finding of the dark small low-albedo bodies, which could approach dangerously closer to the Earth. Equations for Calculation of luminescence intensity of these objects are proposed. Data on the luminescence of the corresponding minerals and the numerical values of the yields of luminescence and albedo, as the conditions for the detectability of the luminescence of Near-Earth Objects are presented as well.

Monthly Notices of the Royal Astronomical Society, 528, 815-820, 2024 (Published)

DOI: 10.1093/mnras/stad3992

An updated fluorescence emission model of CO+ for cometary science

  • Bromley, S. J. 1
  • Noonan, J. Wm. 1
  • Cochran, A. L. 2
  • Stachova, B. 3
  • Orszagh, J. 3
  • Ivanova, O. 4
  • Pierce, D. M. 5
  • Fortenberry, R. C. 6
  • Bodewits, D. 1
  1. Department of Physics, Auburn University, Auburn, AL 36849 USA
  2. Department of Astronomy and McDonald Observatory, University of Texas at Austin, Austin, TX, USA
  3. Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia
  4. Astronomical Institute of the Slovak Academy of Sciences, SK-05960 Tatransk´a Lomnica, Slovak Republic
  5. Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS, USA
  6. Department of Chemistry & Biochemistry, University of Mississippi, University, MS, USA

A new CO+ fluorescence emission model for analyzing cometary spectra is presented herein. Accurate line lists are produced using the PGOPHER software for all transitions between the three electronic states (X 2Σ, A 2Π, B 2Σ) with vibrational states up to vmax = 9, 8, 6, respectively, and maximum rotational states with rotational quantum numbers N ≤ 20. As a result of improved molecular constants and theoretical transition rates, an expansion of the utilized solar spectrum into the infrared, and the substantial expansion of the included rovibronic states, the model provides an update of the fluorescence efficiencies of the CO+ cation. The dependencies on heliocentric velocity and distance are explicitly included. We report, for the first time, quantification of the fluorescence efficiencies for the ground state rovibrational transitions of CO+ and predict the positions and relative intensities of CO+ lines in windows accessible to both ground- and space-based observatories. The computed fluorescence efficiencies show excellent agreement with UV/optical observations of both C/2016 R2 (Pan-STARRS) and 29P/Schwassmann-Wachmann 1. The updated fluorescence efficiencies allow for revised N2/CO abundances for comets 1P/Halley, C/1987 P1 (Bradfield), and C/2016 R2 (Pan-STARRS), which can change by up to 30% when accounting for recent improvements to CO+ and N fluorescence efficiencies. The model code, input files, and fluorescence efficiencies are publicly available and distributed on permanent archives for future uses in cometary analyses.

Monthly Notices of the Royal Astronomical Society (Published)

DOI: 10.1093/mnras/stae456

Serendipitous Archival Observations of a New Ultradistant Comet C/2019 E3 (ATLAS)

  • Man-To Hui 1
  • Robert Weryk 2
  • Marco Micheli 3
  • Zhong Huang 1
  • Richard Wainscoat 4
  1. Macau University of Science and Technology
  2. The University of Western Ontario
  3. ESA NEO Coordination Centre
  4. Institute for Astronomy

We identified a new ultradistant comet C/2019 E3 (ATLAS) exhibiting preperihelion cometary activity at heliocentric distances ≳20 au, making it the fourth member of this population after C/2010 U3 (Boattini), C/2014 UN271 (Bernardinelli-Bernstein), and C/2017 K2 (PANSTARRS). From serendipitous archival data, we conducted analyses of the comet, finding that the activity was consistent with steady-state behavior, suggestive of sublimation of supervolatiles; that the cross section of dust increased gradually on the inbound leg of the orbit, varying with heliocentric distances as rH-1.5±0.4; and that the dust was produced at a rate of ≳102 kg s-1 within the observed timespan. Our modeling of the largely symmetric morphology of the comet suggests that the dust environment was likely dominated by mm-scale dust grains ejected at speeds ≲0.4 m s-1 from the sunlit hemisphere of the nucleus. Assuming a typical geometric albedo of 0.05 and adopting several simplistic thermophysical models, we estimated the nucleus to be at least ∼3 km across. We also measured the color of the comet to be consistent with other long-period comets, except being slightly bluer in g - r. With our astrometric measurements, we determined an improved orbit of the comet, based upon which we derived that the comet is dynamically new and that its perihelion distance will further shrink due to the Galactic tide. We conclude the paper by comparing the known characteristics of the known ultradistant comets.

AJ (Published)

DOI: 10.3847/1538-3881/ad2500 NASA ADS: 2024arXiv240104414H arXiv: 2401.04414