Comets, Centaurs, & TNOs AS3141 Benda Kecil dalam Tata Surya Prodi Astronomi 2007/2008 B. Dermawan

Comets, Centaurs, & TNOs

Jewitt (for 2008)

Comets (1)

Comets (2) Short Period Comet (SPC, < 200 y) - Halley Family Comet (HFC, y) - Jupiter Family Comet (JFC, < 20 y) Long Period Comet (LPC, > 200 y) Ecliptic: T > 2  JFC Isotropic: T < 2  LPC, HFC, Damocloids Ecliptic: T > 2  JFC Isotropic: T < 2  LPC, HFC, Damocloids Tisserand parameter:

Comets (3) Active comet: detectable coma  volatile & dust Inactive comet: no detectable coma Dormant comet: lost the ability to generate a detectable coma in any part of its present orbit  might be reactivated Extinct comet: (= defunc comet?) incapable of generating a coma (lost its ices, or its ices buried under a nonvolatile crust)

Dormant & Extinct Comets Weissman et al. 2003

Comet-like Asteroids & Extinct Comets Weissman et al. 2003

Sun-grazing Comets

Insitu Explorations Giotto → Halley Deep Space 1 – Borrelly Stardust – Wild2 Deep Impact → Tempel 1

Isotopic Abundances Hutsemékers 2005

Mainbelt Comets Hsieh & Jewitt 2006

Damocloids (1) Jewitt (2005) Comet-like asteroids whose T  2 Inactive nuclei of HFC & LPC Have subsequently developed comae About 25% possess retrograde orbits

Damocloids (2) The distribution of inclinations is indistinguishable from that of the HFC Jewitt 2005 : ~4000Å - ~8000Å Jewitt 2005 Lack of ultra-red matter

Centaurs: Asteroid-like objects with semimajor axes between those of Jupiter and Neptune From Jupiter to outer solar system unusual Johnston 2005 Centaurs

Albedo Dotto & Barucci 2004 Delsanti & Jewitt 2006 Dotto & Barucci 2004 Colors

Centaurs Jewitt 2005 Jewitt (for 2008) Hainaut & Delsanti 2005

(Edgeworth)-Kuiper Belt Objects [(E)KBO] Trans-Neptunian Objects (TNOs)

TNOs: Past Evolution (1) Tsiganis et al Dones et al. 2004

TNOs: Past Evolution (2) Morbidelli 2004 Levison & Morbidelli 2003

TNOs: Non-cometary objects with semimajor axes beyond Neptune's orbit Plutinos: Near the 2:3 resonance with Neptune. Pluto is the largest object near this resonance Resonance objects: Other than Plutinos but near resonances (4:5, 3:4, 3:5, 4:7, 1:2, 2:5) with Neptune Cubewanos: Eccentricities below 0.15 with semimajor axes between 41.8 AU and 48 AU (  Classical: cold & hot populations) Scattered disk objects (SDOs): Aphelion distances near Neptune's orbit and semimajor axes greater than 50 AU (+ Extended Scattered or Detached Objects) Other TNOs not fitting in the above groups Plutinos: Near the 2:3 resonance with Neptune. Pluto is the largest object near this resonance Resonance objects: Other than Plutinos but near resonances (4:5, 3:4, 3:5, 4:7, 1:2, 2:5) with Neptune Cubewanos: Eccentricities below 0.15 with semimajor axes between 41.8 AU and 48 AU (  Classical: cold & hot populations) Scattered disk objects (SDOs): Aphelion distances near Neptune's orbit and semimajor axes greater than 50 AU (+ Extended Scattered or Detached Objects) Other TNOs not fitting in the above groups

TNOs: Orbital Distribution Johnston 2005

Number of TNOs (Orbital) Populations Delsanti & Jewitt 2006 Lykawka & Mukai 2007

TNOs: Spectra (1) Dotto & Barucci 2004 Doressoundiram et al. 2007

TNOs: Spectra (2) Doressoundiram et al. 2007

TNOs: Sizes (1) Thermal Flux: Effective temp.: Standard Thermal Model (STM, Lebofsky et al. 1989) Near-Earth Asteroid Thermal Model (NEATM, Harris 1998) Thermo-Physical Model (TPM, Lagerros 1997) Optical Constraints: Density: Bond & Geometric Albedos:

TNOs: Sizes (2) Johnston 2005

Size & Albedo of Unusual Minor Planet C/2002 CE 10 Sekiguchi et al. 2005

Albedo vs Size Jewitt (for 2008)

Albedo & Spectral Gradient Jewitt 2004 Fernandez et al Jewitt et al Cruikshank et al. 2006

Colors (1) Jewitt 2005 Peixinho 2003

Colors (2) Doressoundiram & Peixinho 2005

Colors (3) Delsanti & Jewitt 2006

Large TNOs  Dwarf Planets

Large TNOs (Dwarf Planets): Spectra (1) Jewitt et al (50000) Quaoar

Large TNOs (Dwarf Planets): Spectra (2) Brown 2006 Pluto & 2003 UB313

Small Body Binary (1) Richardson & Walsh 2005 NEAsMBAs Trojan Pluto- Charon TNOs

Small Body Binary (2) Richardson & Walsh 2005 NEAsMBAs Trojan Pluto- Charon TNOs

Dwarf Planet Binary May 2006

Stellar Encounter (1) Morbidelli & Levison 2004

Stellar Encounter (2) Kenyon & Bromley 2004

Stellar Encounter (2) Kenyon & Bromley 2004

Stellar Encounter (2) Kenyon & Bromley 2004