Blending the distinctions among groups of minor bodies: a portrait of the Centaur-comet “transition” object P/2010 C1 (Scotti)^⋆

¹ INAF – Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
e-mail: epifani@oacn.inaf.it
² LESIA – Observatoire de Paris, CNRS, UPMC, Université Paris-Diderot, 5 place Jules Janssen, 92195 Meudon Cedex, France
³ Instituto de Astrofísica de Canarias, c/vía Láctea s/n, 38200 , La Laguna, Tenerife, Spain
⁴ Departamento de Astrofísica, Universidad de La Laguna, 38205, La Laguna, Tenerife, Spain
⁵ Universitá Parthenope, Dip. Scienze Applicate, Centro Direzionale Isola C4, 80143 Napoli, Italy
⁶ INAF – Osservatorio Astronomico di Roma, via Di Frascati 33, 00040 Monte Porzio Catone, Roma, Italy
⁷ INAF – Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
⁸ INAF – IAPS, via Del Fosso del Cavaliere 100, 00133 Roma, Italy

Received: 27 September 2013
Accepted: 18 March 2014

Abstract

Aims. We present a portrait of the active Centaur P/2010 C1 (Scotti), observed with a well developed comet-like activity (central diffuse coma condensation and an extended sharp tail-like structure) at the heliocentric distance of r_h = 5.5 AU.

Methods. We analyse multicolour (B, V, R, and I) images taken at the TNG telescope to characterise the dust coma of the active Centaur and to investigate its photometry, colours, and dust production, and to gain hints to its nucleus size.

Results. P/2010 C1 (Scotti) has a small nucleus (<4.8 km in radius), with visual colour V − R = 0.49 ± 0.03 typical of the nuclei of Jupiter-family comets, but with a dust coma much redder (B − I = 2.37 ± 0.13) than both the Sun and the typical comet mucleus. It has an integrated R magnitude of m_R = 21.41 ± 0.02 and R-Afρ = 34 ± 2 cm (all measured in the reference aperture of radius φ = 2.0′′), which is much lower than has been measured for other active Centaurs at similar heliocentric distances. Its dust production rate, Q_d = 0.1–15 kg/s, depicts P/2010 C1 (Scotti) as a rather weak dust emitter, with a dust-loss rate comparable to that of the weakest Jupiter-family comets at shorter heliocentric distance and to the weakest active Centaur characterised to now.