Initial Characterization of Active Transitioning Centaur, P/2019 LD2 (ATLAS), using Hubble, Spitzer, ZTF, Keck, APO and GROWTH Visible & Infrared Imaging and Spectroscopy

Bryce T. Bolin, Yanga R. Fernandez, Carey M. Lisse, Timothy R. Holt, Zhong-Yi Lin, Josiah N. Purdum, Kunal P. Deshmukh, James M. Bauer, Eric C. Bellm, Dennis Bodewits, Kevin B. Burdge, Sean J. Carey, Chris M. Copperwheat, George Helou, Anna Y. Q. Ho, Jonathan Horner, Jan van Roestel, Varun Bhalerao, Chan-Kao Chang, Christine Chen, Chen-Yen Hsu, Wing-Huen Ip, Mansi M. Kasliwal, Frank J. Masci, Chow-Choong Ngeow, Robert Quimby, Rick Burruss, Michael Coughlin, Richard Dekany, Alexandre Delacroix, Andrew Drake, Dmitry A. Duev, Matthew Graham, David Hale, Thomas Kupfer, Russ R. Laher, Ashish Mahabal, Przemyslaw J. Mróz, James D. Neill, Reed Riddle, Hector Rodriguez, Roger M. Smith, Maayane T. Soumagnac, Richard Walters, Lin Yan, Jeffry Zolkower

January 2021

Abstract

We present visible and mid-infrared imagery and photometry of temporary Jovian co-orbital comet P/2019 LD $_{2}$ taken with HST/WFC3, Spitzer/IRAC, the GROWTH telescope network, visible spectroscopy from Keck/LRIS and archival ZTF observations taken between 2019 April and 2020 August. Our observations indicate that the nucleus of LD $_{2}$ has a radius between 0.2-1.8 km assuming a 0.08 albedo and a coma dominated by $s i m$ 100 $m u$ m-scale dust ejected at $s i m$ 1 m/s speeds with a $s i m$ 1” jet pointing in the SW direction. LD $_{2}$ experienced a total dust mass loss of $s i m$ 10 $^{8}$ kg at a loss rate of $s i m$ 6 kg/s with Af $r h o$ /cross-section varying between $s i m$ 85 cm/125 km $^{2}$ and $s i m$ 200 cm/310 km $^{2}$ from 2019 April 9 to 2019 Nov 8. If the increase in Af $r h o$ /cross-section remained constant, it implies LD $_{2}$ ’s activity began $s i m$ 2018 November when within 4.8 au of the Sun, implying the onset of H $_{2}$ O sublimation. We measure CO/CO $_{2}$ gas production of $l e s s s i m$ 10 $^{27}$ mol/s / $l e s s s i m$ 10 $^{26}$ mol/s from our 4.5 $m u$ m Spitzer observations, $g$ - $r$ = 0.59 $p m$ 0.03, $r$ - $i$ = 0.18 $p m$ 0.05, $i$ - $z$ = 0.01 $p m$ 0.07 from GROWTH observations, H $_{2}$ O gas production of $l e s s s i m$ 80 kg/s scaling from our estimated $C2 $p r o d u c t i o n o f$ Q{C_2}lesssim $7.5$ times10^{24} $m o l / s f r o m K e c k / L R I S s p e c t r o s c o p y . W e d e t e r m i n e t h a t t h e l o n g - t e r m o r b i t o f L D$ _2 $i s s i m i l a r t o J u p i t e r f a m i l y c o m e t s h a v i n g c l o s e e n c o u n t e r s w i t h J u p i t e r w i t h i n$ sim $0.5 H i l l r a d i u s i n t h e l a s t$ sim $3 y, w i t h i n 0.8 H i l l r a d i u s i n$ sim $9 y . A d d i t i o n a l l y, 78.8$ % $o f o u r o r b i t a l c l o n e s a r e e j e c t e d f r o m t h e S o l a r S y s t e m w i t h i n$ 1 times 10^{6} $y e a r s h a v i n g a d y n a m i c a l h a l f - l i f e o f 3.4$ times 10^5$ years.

Type

Journal article

http://arxiv.org/abs/2011.03782v2