A stellar occultation by Vanth, a satellite of (90482) Orcus

Sickafoose, Amanda A.; Bosh, A. S.; Levine, S. E.; Zuluaga, C. A.; Genade, Anja; Schindler, Karsten; Lister, Tim

doi:10.1016/j.icarus.2018.10.016

Cited by 18 publications

(11 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The catalog provides this flag for any detection inside a radius of 2 from another source. However, undetected close companions can be missed by Gaia, as in the case described in Sickafoose et al (2019). (3) The reference epoch for the astrometric positions provided by Gaia DR2 is J2015.5.…”

Section: Discussionmentioning

confidence: 99%

Stellar occultations enable milliarcsecond astrometry for Trans-Neptunian objects and Centaurs

Rommel

Braga-Ribas

Desmars

et al. 2020

A&A

View full text Add to dashboard Cite

Context. Trans-Neptunian objects (TNOs) and Centaurs are remnants of our planetary system formation, and their physical properties have invaluable information for evolutionary theories. Stellar occultation is a ground-based method for studying these distant small bodies and has presented exciting results. These observations can provide precise profiles of the involved body, allowing an accurate determination of its size and shape. Aims. The goal is to show that even single-chord detections of TNOs allow us to measure their milliarcsecond astrometric positions in the reference frame of the Gaia second data release (DR2). Accurate ephemerides can then be generated, allowing predictions of stellar occultations with much higher reliability. Methods. We analyzed data from various stellar occultation detections to obtain astrometric positions of the involved bodies. The events published before the Gaia era were updated so that the Gaia DR2 stellar catalog is the reference, thus providing accurate positions. Events with detection from one or two different sites (single or double chord) were analyzed to determine the event duration. Previously determined sizes were used to calculate the position of the object center and its corresponding error with respectto the detected chord and the International Celestial Reference System propagated Gaia DR2 star position. Results. We derive 37 precise astrometric positions for 19 TNOs and four Centaurs. Twenty-one of these events are presented here for the first time. Although about 68% of our results are based on single-chord detection, most have intrinsic precision at the submilliarcsecond level. Lower limits on the diameter of bodies such as Sedna, 2002 KX14, and Echeclus, and also shape constraints on 2002 VE95, 2003 FF128, and 2005 TV189 are presented as valuable byproducts. Conclusions. Using the Gaia DR2 catalog, we show that even a single detection of a stellar occultation allows improving the object ephemeris significantly, which in turn enables predicting a future stellar occultation with high accuracy. Observational campaigns can be efficiently organized with this help, and may provide a full physical characterization of the involved object, or even the study of topographic features such as satellites or rings.

show abstract

Section: Discussionmentioning

confidence: 99%

Stellar occultations enable milliarcsecond astrometry for Trans-Neptunian objects and Centaurs

Rommel

Braga-Ribas

Desmars

et al. 2020

A&A

View full text Add to dashboard Cite

show abstract

“…The data-set includes the separation and position angle of the satellite relative to the primary body. For three events -Pluto (Charon) on 2005 Jul 11, (617) Patroclus on 2010 June 14, and (90482) Orcus (Vanth) on 2017 Mar 7 (Sickafoose et al 2019)an occultation by the satellite was observed, but not the main body. For satellites of the major planets (such as Charon), the reduction is based on the known position of the satellite relative to the planetwith no separation and position angle being derived.…”

Section: Binary Asteroids and Asteroid Satellitesmentioning

confidence: 92%

Precise astrometry and diameters of asteroids from occultations -- a data-set of observations and their interpretation

Herald,

Gault,

Anderson

et al. 2020

Preprint

View full text Add to dashboard Cite

Occultations of stars by asteroids have been observed since 1961, increasing from a very small number to now over 500 annually. We have created and regularly maintain a growing data-set of more than 5,000 observed asteroidal occultations. The data-set includes: the raw observations; astrometry at the 1 mas level based on centre of mass or figure (not illumination); where possible the asteroid's diameter to 5 km or better, and fits to shape models; the separation and diameters of asteroidal satellites; and double star discoveries with typical separations being in the tens of mas or less. The data-set is published at NASA's Planetary Data System and is regularly updated. We provide here an overview of the data-set, discuss the issues associated with determining the astrometry and diameters, and give examples of what can be derived from the data-set. We also compare the occultation diameters of asteroids with the diameters measured by the satellites NEOWISE, AKARI AcuA, and IRAS, and show that the best satellite-determined diameter is a combination of the diameters from all three satellites.

show abstract

“…Another appeal of this network lies within its ability to pinpoint the positions of distant minor planets, such as TNOs, to high precision. While challenging, stellar occultation measurements of TNOs have been successfully demonstrated on several occasions (Ortiz et al 2017;Müller et al 2018;Sickafoose et al 2019) and have become increasingly accessible with the advent of Gaia DR2. Deep sky surveys such as the Dark Energy Survey (Dark Energy Survey Collaboration: Fermilab & Flaugher 2005) can also provide astrometric measurements of TNOs with sufficient accuracy to reliably predict upcoming occultation events (Banda-Huarca et al 2018).…”

Section: An Acceleration Map Of the Outer Solar Systemmentioning

confidence: 99%

The Case for a Large-scale Occultation Network

Rice¹,

Laughlin²

2019

View full text Add to dashboard Cite

We discuss the feasibility of and present initial designs and approximate cost estimates for a large (N ∼ 2000) network of small photometric telescopes that is purpose-built to monitor V 15 Gaia Mission program stars for occultations by minor solar system bodies. The implementation of this network would permit measurement of the solar system's tidal gravity field to high precision, thereby revealing the existence of distant trans-Neptunian objects such as the proposed "Planet Nine." As a detailed example of the network capabilities, we investigate how occultations by Jovian Trojans can be monitored to track the accumulation of gravitational perturbations, thereby constraining the presence of undetected massive solar system bodies. We also show that the tidal influence of Planet Nine can be discerned from that of smaller, nearer objects in the Kuiper belt. Moreover, ephemerides for all small solar system bodies observed in occultation could be significantly improved using this network, thereby improving spacecraft navigation and refining Solar System modeling. Finally, occultation monitoring would generate direct measurements of size distributions for asteroid populations, permitting a better understanding of their origins.

show abstract

A stellar occultation by Vanth, a satellite of (90482) Orcus

Cited by 18 publications

References 48 publications

Stellar occultations enable milliarcsecond astrometry for Trans-Neptunian objects and Centaurs

Stellar occultations enable milliarcsecond astrometry for Trans-Neptunian objects and Centaurs

Precise astrometry and diameters of asteroids from occultations -- a data-set of observations and their interpretation

The Case for a Large-scale Occultation Network

Contact Info

Product

Resources

About