Published September 1, 2022 | Version public
Journal Article

Asteroid Measurements at Millimeter Wavelengths with the South Pole Telescope

Creators

  • 1. ROR icon University of Chicago
  • 2. ROR icon Case Western Reserve University
  • 3. ROR icon University of Illinois Urbana-Champaign
  • 4. ROR icon University of Redlands
  • 5. ROR icon Cardiff University
  • 6. ROR icon Stanford University
  • 7. ROR icon SLAC National Accelerator Laboratory
  • 8. ROR icon Fermilab
  • 9. ROR icon National Center for Supercomputing Applications
  • 10. ROR icon National Institute of Standards and Technology
  • 11. ROR icon University of Colorado Boulder
  • 12. ROR icon University of California, Berkeley
  • 13. ROR icon University of Melbourne
  • 14. ROR icon Argonne National Laboratory
  • 15. ROR icon California Institute of Technology
  • 16. ROR icon Institut d'Astrophysique de Paris
  • 17. ROR icon McGill University
  • 18. ROR icon University of KwaZulu-Natal
  • 19. ROR icon University of Toronto
  • 20. ROR icon Canadian Institute for Advanced Research
  • 21. ROR icon University of Science and Technology of China
  • 22. ROR icon University of California, Los Angeles
  • 23. ROR icon Harvey Mudd College
  • 24. ROR icon European Southern Observatory
  • 25. ROR icon High Energy Accelerator Research Organization
  • 26. ROR icon University of California, Davis
  • 27. ROR icon University of Pennsylvania
  • 28. ROR icon Lawrence Berkeley National Laboratory
  • 29. ROR icon University of Arizona
  • 30. ROR icon University of Oslo
  • 31. ROR icon University of Minnesota
  • 32. ROR icon Yale University
  • 33. ROR icon Art Institute of Chicago
  • 34. ROR icon Three-Speed Logic (Canada)
  • 35. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 36. ROR icon Southwest Research Institute
  • 37. ROR icon Michigan State University

Abstract

We present the first measurements of asteroids in millimeter wavelength data from the South Pole Telescope (SPT), which is used primarily to study the cosmic microwave background (CMB). We analyze maps of two ∼270 deg² sky regions near the ecliptic plane, each observed with the SPTpol camera ∼100 times over 1 month. We subtract the mean of all maps of a given field, removing static sky signal, and then average the mean-subtracted maps at known asteroid locations. We detect three asteroids -- (324) Bamberga, (13) Egeria, and (22) Kalliope -- with signal-to-noise ratios (S/N) of 11.2, 10.4, and 6.1, respectively, at 2.0 mm (150 GHz); we also detect (324) Bamberga with an S/N of 4.1 at 3.2 mm (95 GHz). We place constraints on these asteroids' effective emissivities, brightness temperatures, and light-curve modulation amplitude. Our flux density measurements of (324) Bamberga and (13) Egeria roughly agree with predictions, while our measurements of (22) Kalliope suggest lower flux, corresponding to effective emissivities of 0.64 ± 0.11 at 2.0 and < 0.47 at 3.2 mm. We predict the asteroids detectable in other SPT data sets and find good agreement with detections of (772) Tanete and (1093) Freda in recent data from the SPT-3G camera, which has ∼10× the mapping speed of SPTpol. This work is the first focused analysis of asteroids in data from CMB surveys, and it demonstrates we can repurpose historic and future data sets for asteroid studies. Future SPT measurements can help constrain the distribution of surface properties over a larger asteroid population.

Additional Information

This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00001.CAL. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This publication also makes use of data products from NEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of Technology, funded by the Planetary Science Division of the National Aeronautics and Space Administration. M.A. and J.V. acknowledge support from the Center for AstroPhysical Surveys at the National Center for Supercomputing Applications in Urbana, IL. J.V. acknowledges support from the Sloan Foundation. The authors thank Jeff McMahon 55 for support in manuscript preparation through the Science Writing Practicum taught as part of U. Chicago's "Data Science in Energy and Environmental Research" NRT training program, NSF grant #DGE-1735359.

Additional details

Identifiers

Eprint ID
117116
Resolver ID
CaltechAUTHORS:20220922-931611600.14

Funding

National Science Foundation
OPP-1852617

Dates

Created
2022-09-28
Created from EPrint's datestamp field
Updated
2022-09-28
Created from EPrint's last_modified field