Visible-Infrared spectral characterization of 3200 Phaethon at its closest approach to Earth
Abstract
The asteroid 3200 Phaethon is a peculiar object with a very eccentric orbit with a perihelion located at only 0.14 AU and it has been dynamically associated with the Geminid meteor stream (Gustafson 1989; Williams & Wu 1993; Jenniskens 2006, and references therein). Phaethon is a B-class asteroid and it is linked with carbonaceous species and hydrated silicates such as phyllosilicates. Good match of the Phaeton spectra are the aqueously altered CI/CM meteorites (Licandro, 2007) and the CK meteorites (Clark et al. 2010). The asteroid 3200 Phaethon is the target of the Destiny + Space mission, managed by Japanese Space Agency (Jaxa), which will perform a close rendevouz with this asteroid, with the scientific objectives of studying its surface properties and assessing its cometary activity in terms of release of dust and volatiles. The December 2017 Phaethon Earth approach have been a very important event since it was about 10 times closer than any other future approach predicted at least for the next 20 years. In that occasion, we observed the asteroid at the 3.5 mt Telescopio Nazionale Galileo in the spectral interval (0.4-2-5 μm).We obtained three spectra in the Visible from 0.4 to 0.8 μmm, with a strong fringing longward of 0.8 μmm which doesn't allow to use the data between 0.8 and 1 μmm. The spectra are featureless, however, the slope of two spectra agrees well with many previous observations of Phaeton (see e.g. Licandro et al, 2006). One spectra show, instead, a bluer behaviour, similarly to the unique previous observation by Luu and Jewitt (1993). The IR spectrum is almost featureless, with very weak features at the limit of the S/N which at present are under investigation.
- Publication:
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42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E2561P