3200) Phaethon exhibits both comet-and asteroid-like properties, suggesting it could be a rare transitional object such as a dormant comet or previously volatile-rich asteroid. This justifies detailed study of (3200) Phaethon's physical properties, as a better understanding of asteroid-comet transition objects can provide insight into minor body evolution. We therefore acquired time-series photometry of (3200) Phaethon over 15 nights from 1994 to 2013, primarily using the Tektronix 2048×2048 pixel CCD on the University of Hawaii 2.2-m telescope. We utilized light curve inversion to: (1) refine (3200) Phaethon's rotational period to P = 3.6032 ± 0.0008 h; (2) estimate a rotational pole orientation of λ = +85 • ± 13 • and β = −20 • ± 10 • ; and (3) derive a shape model. We also used our extensive light curve dataset to estimate the slope parameter of (3200) Phaethon's phase curve as G ∼ 0.06, consistent with C-type asteroids. We discuss how this highly oblique pole orientation with a negative ecliptic latitude supports previous evidence for (3200) Phaethon's origin in the inner main asteroid belt as well as the potential for deeply buried volatiles fueling impulsive yet rare cometary outbursts.We obtained time-series photometry over 15 nights from 1994 to 2013. These observations are summarized in Table 1. All but three nights used the Tektronix 2048×2048 pixel CCD camera on the University of Hawaii 2.2-m telescope on Mauna Kea. Two nights used the PRISM 2048×2048 pixel CCD camera on the Perkins 72-in telescope at the Lowell Observatory in Flagstaff, Arizona, while one night used the Optic 2048×4096 CCD camera also on the University of Hawaii 2.2-m telescope. All observations used the standard Kron-Cousins R filter with the telescope guiding on (3200) Phaethon at non-sidereal rates. Reduction & PhotometryRaw images were processed with standard IRAF routines for bias subtraction, flatfielding, and cosmic ray removal (Tody 1986). We constructed reference flat-fields by median combining dithered images of either twilight or the object field (in both cases, flattening reduced gradients to <1% across the CCD). We performed photometry using the IRAF phot routine with circular apertures typically 5 ′′ in radius, although aperture sizes changed depending on the night and/or exposure as they were chosen to consistently include 99.5% of the object's light. Sky subtraction used either an annulus around the photometry aperture or median-combined samples of nearby patches of clear sky. (3200) Phaethon appeared point-like in all images, justifying our use of aperture photometry.

Earth-and space-based observations provide synergistic information for space mission encounters by providing data over longer timescales, at different wavelengths and using techniques that are impossible with an in situ flyby. We report here such observations in support of the EPOXI spacecraft flyby of comet 103P/Hartley 2. The nucleus is small and dark, and exhibited a very rapidly changing rotation period. Prior to the onset of activity, the period

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The main-belt asteroid (300163) 2006 VW 139 (later designated P/2006 VW 139 ) was discovered to exhibit comet-like activity by the Pan-STARRS1 (PS1) survey telescope using automated point-spread-function analyses performed by PS1's Moving Object Processing System. Deep follow-up observations show both a short (∼10 ) antisolar dust tail and a longer (∼60 ) dust trail aligned with the object's orbit plane, similar to the morphology observed for another main-belt comet (MBC), P/2010 R2 (La Sagra), and other well-established comets, implying the action of a long-lived, sublimation-driven emission event. Photometry showing the brightness of the near-nucleus coma remaining constant over ∼30 days provides further evidence for this object's cometary nature, suggesting it is in fact an MBC, and not a disrupted asteroid. A spectroscopic search for CN emission was unsuccessful, though we find an upper limit CN production rate of Q CN < 1.3 × 10 24 mol s −1 , from which we infer a water production rate of Q H 2 O < 10 26 mol s −1 . We also find an approximately linear optical spectral slope of 7.2%/1000 Å, similar to other cometary dust comae. Numerical simulations indicate that P/2006 VW 139 is dynamically stable for >100 Myr, while a search for a potential asteroid family around the object reveals a cluster of 24 asteroids within a cutoff distance of 68 m s −1 . At 70 m s −1 , this cluster merges with the Themis family, suggesting that it could be similar to the Beagle family to which another MBC, 133P/Elst-Pizarro, belongs.