Characterization of the Nucleus, Morphology, and Activity of Interstellar Comet 2I/Borisov by Optical and Near-infrared GROWTH, Apache Point, IRTF, ZTF, and Keck Observations

  title={Characterization of the Nucleus, Morphology, and Activity of Interstellar Comet 2I/Borisov by Optical and Near-infrared GROWTH, Apache Point, IRTF, ZTF, and Keck Observations},
  author={Bryce T. Bolin and Carey M. Lisse and Mansi M. Kasliwal and Robert M. Quimby and Hanjie Tan and C. M. Copperwheat and Zhong-Yi Lin and Alessandro Morbidelli and Lyu Abe and Philippe P. Bendjoya and James M. Bauer and Kevin B Burdge and Michael W. Coughlin and Christoffer U. Fremling and Ryosuke Itoh and Michael Koss and Frank J. Masci and Syota Maeno and Eric E. Mamajek and Federico Marocco and Katsuhiro L. Murata and Jean-Pierre Rivet and Michael L. Sitko and Daniel Stern and David Vernet and R. Walters and Lin Yan and Igor Andreoni and Varun Bhalerao and Dennis Bodewits and Kishalay De and Kunal P. Deshmukh and Eric C. Bellm and Nadejda Blagorodnova and Derek L. Buzasi and S. Bradley Cenko and Chan-Kao Chang and Drew Chojnowski and Richard Dekany and D. Duev and Matthew J. Graham and Mario Juri{\'c} and Emily Kramer and Shrinivas R. Kulkarni and Thomas Kupfer and Ashish A. Mahabal and James D. Neill and Chow-Choong Ngeow and Bryan Edward Penprase and Reed L. Riddle and Hector Rodriguez and Philippe Rosnet and Roger M. Smith and Jesper Sollerman and Maayane T. Soumagnac},
  journal={The Astronomical Journal},
We present visible and near-infrared photometric and spectroscopic observations of interstellar object 2I/Borisov taken from 2019 September 10 to 2019 November 29 using the GROWTH, the APO ARC 3.5 m and the NASA/IRTF 3.0 m combined with post and pre-discovery observations of 2I obtained by ZTF from 2019 March 17 to 2019 May 5. Comparison with imaging of distant Solar System comets shows an object very similar to mildly active Solar System comets with an out-gassing rate of $\sim$10$^{27}$ mol… 

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