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Proposal Identification No.:

A2384

Date Received:

2008-Feb-08 09:21:15

Technical Page
Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Minimum Useful Time: Prop osal Title: ABSTRACT: Regular Astronomy Spectroscopy Solar System 15 Hours 2 hours

Radio OH observatons of long-period Comet Boattini (2007 W1)

Radio observations of the 18-cm OH lines provide unique insight into the water production of comets and the outflow velocity of the gas. Other measurements of trace gases depend on the measured water production to obtain the total mass. Water can be difficult to observe from the ground, and these OH lines are one of the few direct ways to measure this. We have observed sixteen comets in the last 8 years, and find a wide variety of outflow behaviors: every comet is different. When the lines are bright enough, we can measure both a nucleus centered line, and positions 4 arcmin into the coma. This allows us to measure the degree of collisional quenching that is present, and this too has been variable. Some comets follow predictions, some are well above, others well below. Without a larger sample of comets we cannot determine whether these differences are intrinsic to the comet, or depend on their being short-period or long-period. Comet Boattini is also close enough for some radar observations, and we intend to cooperate with that observing team to make best use of the time allocated.

Name Ellen S Howell

Institution Arecibo Observatory

E-mail ehowell@naic.edu

Phone 787 878-2612 282

Student no

Remote Observing Request

Observer will travel to AO Remote Observing X In Absentia (instructions to operator)

Instrument Setup
L-wide Atmospheric Observation Instruments:

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Sp ecial Equipment or setup: Ephemeris tracking using the new CIMA would be helpful.

RFI Considerations Frequency Ranges Planned

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