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High resolution spectra of Comet 8P/Tuttle were obtained in the frequency range 3440.6-3462.6 cm-1 on 3 January 2008 UT using CGS4 with echelle grating on UKIRT. In addition to recording strong solar pumped fluorescent (SPF) lines of H2O, the long integration time (152 miutes on target) enabled eight weaker H2O features to be assigned, most of which had not previously been identified in cometary spectra. These transitions, which are from higher energy upper states, are similar in character to the so-called SH lines recorded in the post Deep Impact spectrum of comet Tempel 1 (Barber et al., 2007). We have identified certain characteristics that these lines have in common, and which in addition to helping to define this new class of cometary line, give some clues to the physical processes involved in their production. Finally, we derive an H2O rotational temperature of 62+/- K and a water production rate of (1.4+/-0.3)E28 molecules/s.
Comet 8P/Tuttle is a Nearly Isotropic Comet (NIC), whose physical properties are poorly known and could be different from those of Ecliptic Comets (EC) owing to their different origin. Two independent observations have shown that 8P has a bilobate nu
We measured organic volatiles (CH4, CH3OH, C2H6, H2CO), CO, and water in comet 8P/Tuttle, a comet from the Oort cloud reservoir now in a short-period Halley-type orbit. We compare its composition with two other comets in Halley-type orbits, and with
We present results for Chandra observations of comets, 17P/Holmes (17P) and 8P/Tuttle (8P). 17P was observed for 30 ksec right after its major outburst, on 31 Oct 2007 (10:07 UT) and comet 8P/Tuttle was observed in 2008 January for 47 ksec. During th
Cometary outgassing can produce torques that change the spin state of the nucleus, influencing the evolution and lifetimes of comets (1,2). If these torques spin up the rotation to the point that centripetal forces exceed the material strength of the
A search for the near-infrared water-ice absorption band was made in a number of very red OH/IR stars which are known to exhibit the 10um silicate absorption. As a by-product, accurate positions of these highly reddened objects are obtained. We deriv