Activity of the Jupiter co-orbital comet P/2019 LD<SUB>2</SUB> (ATLAS) observed with OSIRIS at the 10.4 m GTC

DOI: 
10.1051/0004-6361/202038842
Publication date: 
24/06/2021
Main author: 
Licandro, J.
IAA authors: 
Moreno, F.;Lara, L.
Authors: 
Licandro, J.;de León, J.;Moreno, F.;de la Fuente Marcos, C.;de la Fuente Marcos, R.;Cabrera-Lavers, A.;Lara, L.;de Souza-Feliciano, A.;De Prá, M.;Pinilla-Alonso, N.;Geier, S.
Journal: 
Astronomy and Astrophysics
Publication type: 
Article
Volume: 
650
Pages: 
A79
Abstract: 
Context. The existence of comets with heliocentric orbital periods close to that of Jupiter (i.e., co-orbitals) has been known for some time. Comet 295P/LINEAR (2002 AR<SUB>2</SUB>) is a well-known quasi-satellite of Jupiter. However, their orbits are not long-term stable, and they may eventually experience flybys with Jupiter at very close range, close enough to trigger tidal disruptions like the one suffered by comet Shoemaker-Levy 9 in 1992. <BR /> Aims: Our aim was to study the observed activity and the dynamical evolution of the Jupiter transient co-orbital comet P/2019 LD<SUB>2</SUB> (ATLAS) and its dynamical evolution. <BR /> Methods: We present results of an observational study of P/2019 LD<SUB>2</SUB> carried out with the 10.4 m Gran Telescopio Canarias (GTC) that includes image analyses using a Monte Carlo dust tail fitting code to characterize its level of cometary activity, and spectroscopic studies to search for gas emission. We also present N-body simulations to explore its past, present, and future orbital evolution. <BR /> Results: Images of P/2019 LD<SUB>2</SUB> obtained on May 16, 2020, show a conspicuous coma and tail, but the spectrum obtained on May 17, 2020, does not exhibit any evidence of CN, C<SUB>2</SUB>, or C<SUB>3</SUB> emission. The comet brightness in a 2.6'' aperture diameter is r' = 19.34 ± 0.02 mag, with colors (g'− r') = 0.78 ± 0.03, (r'− i') = 0.31 ± 0.03, and (i'− z') = 0.26 ± 0.03. The temporal dependence of the dust loss rate of P/2019 LD<SUB>2</SUB> can be parameterized by a Gaussian function having a full width at half maximum of 350 days, with a maximum dust mass loss rate of 60 kg s<SUP>−1</SUP> reached on August 15, 2019. The total dust loss rate from the beginning of activity until the GTC observation date (May 16, 2020) is estimated at 1.9 × 10<SUP>9</SUP> kg. Comet P/2019 LD<SUB>2</SUB> is now an ephemeral co-orbital of Jupiter, following what looks like a short arc of a quasi-satellite cycle that started in 2017 and will end in 2028. On January 23, 2063, it will experience a very close encounter with Jupiter at perhaps 0.016 au; its probability of escaping the solar system during the next 0.5 Myr is estimated to be 0.53 ± 0.03. <BR /> Conclusions: Photometry and tail model results show that P/2019 LD<SUB>2</SUB> is a kilometer-sized object, in the size range of the Jupiter-family comets, with a typical comet-like activity most likely linked to sublimation of crystalline water ice and clathrates. Its origin is still an open question. Our numerical studies give a probability of this comet having been captured from interstellar space during the last 0.5 Myr of 0.49 ± 0.02 (average and standard deviation), 0.67 ± 0.06 during the last 1 Myr, 0.83 ± 0.06 over 3 Myr, and 0.91 ± 0.09 during the last 5 Myr. <P />Based on observations made with the GTC telescope, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias (program ID GTCMULTIPLE2F-20A).
Database: 
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2021A&A...650A..79L/abstract
ADS Bibcode: 
2021A&A...650A..79L
Keywords: 
comets: general;comets: individual: P/2019 LD2 (ATLAS);methods: numerical;methods: observational;Astrophysics - Earth and Planetary Astrophysics