Kirjoittaja Aihe: Vestoidien fotometrian tutkimusverkosto keväälle  (Luettu 2185 kertaa)

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Poissa Jarmo

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Tiedoksi kaikille joilla sattuu olemaan hommaan sopivat välineet ja taidot. Tutkimusryhmä kaipaa vestoidien (eli V-tyypin asteroidien, eli Vestasta todennäköisesti irronneiden palasten) havainnointia mahdollisimman monesta kulmasta alkuvuodesta, ja tietysti mahdollisimman tarkasti. En suomenna enempää koska verkostossa pitänee osata ulkomaata.  :wink:


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Subject: DAWN mission support: Request for ground-based vestoid photometry

Dear Colleagues.

Dr. Bonnie Buratti and I are members of the DAWN science team and we are in the process of generating a photometric model of 4 Vesta in anticipation of spacecraft rendezvous in August 2011.  Ground-based photometry of V-type asteroids (Vestoids) over a wide range of solar phase angles would be extremely useful in constraining our model.  We would like to ask if you might like to join us in this effort.

We have identified three Vestoids that are well-placed for observation during spring of 2011:  1981 Midas, 4668 (1980 WF), and 137052 (1998 VO3). All three are near-Earth asteroids and all three should be brighter than V~18 for a significant portion of their apparitions.

At the bottom of this message are three figures that show phase angle, declination, and elongation as functions of time for our targets.  Only elongations greater than 60 degrees plotted and all objects are observable from late December to early March.  4888 (1980 WF) remains near the ecliptic throughout the apparition while 137052 (1998 VO33) and 1981 Midas will be best observed from the northern and southern hemispheres, respectively.

Bonnie and I will be using the JPL Table Mountain Observation (TMO) 0.6-m telescope, which can comfortably reach V~18 and -30 deg dec, depending on the seeing and solar elongation.  All observations will be made using the the faculty Bessel R filter, calibrated nightly using Landolt standard fields.  Other flavors of filters that potential collaborators may have available, such as Johnson V or R, can be combined with our data using SMASS spectroscopy.  Photometry would likely have to be accurate to 0.1 mag to be useful although more precisenphotometry (preferably to 0.01 mag) would allow us to subtract rotational lightcurve effects.

If you would like to join us in this project we would most welcome your help.  Please contact myself or Bonnie.  And of course any collaborators would be coauthors on any publication that utilizes the data.

Yours yery truly

-Mike Hicks

Dr. Michael D. Hicks           Asteroids, Comets & Satellites Group
(818)354-4256 (W)              CalTech/Jet Propulsion Laboratory MS
(818)354-0966 (F)              4800 Oak Grove Drive, Pasadena CA 91109