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Electronic Telegram No.  512 
Central Bureau for Astronomical Telegrams 
INTERNATIONAL ASTRONOMICAL UNION 
 
2002 JF_56 
     R. Binzel, Massachusetts Institute of Technology, writes that 
ground-based photometric and spectroscopic observations are requested 
for 2002 JF_56, in support of the June 13 passage (at 100000 km) of the 
minor planet by the NASA New Horizons spacecraft, which will use 
the encounter for instrument calibration and testing of moving-target 
tracking.  Possible photometric and spectroscopic measurements obtained 
by the spacecraft will be most useful if supported by ground-based 
observations.  Interested observers may contact Binzel (rpb at mit.edu). 

What Observations Are Needed?

Most useful would be lightcurve information and basic color information, such as V−R, on the standard magnitude system. We can benefit by having observations as soon as possible so as to learn the lightcurve amplitude and rotation period. At present, there are no lightcurve measurements known.

If you are interested in observing, or can report specific observing plans or results, please communicate with Richard Binzel (rpb at mit.edu). Updates will be posted here, as received.

Observing Circumstances for 2002 JF₅₆:

UT 2006 May 21: RA = 13:14; Dec = −5; Elong = 140; V mag = 19.1

Specific Observational Plans Reported

• UT Date(s): 28 May 2006 UT

  Observers: J. Scotti

  Contact: jscotti at lpl.arizona.edu

  Telescope: Spacewatch

  Proposed Observations:

  Lightcurve measurements

• UT Date(s): 30, 31 May and 1 June 2006 UT

  Observers: L. Barrera, H. Boehnhardt

  Contact: boehnhardt at linmpi.mpg.de

  Telescope: VLT

  Report:

  R images, Visible wavelength spectra

• Observers: D. Tholen, F. Bernardi

  Contact: tholen at IfA.Hawaii.Edu

  Telescope: U. Hawaii 88-inch (Mauna Kea)

  UT Dates: 1 June and 2 June

  Proposed Observations:

  BVRI Photometry for colors and lightcurve

• Observers: A. Tokunaga, R. Binzel

  Contact: rpb at mit.edu

  Telescope: NASA IRTF 3.0m (Mauna Kea)

  UT Dates: 2 June and 3 June

  Proposed Observations:

  J,H,K lightcurve photometry, pending outcome of Tholen / Bernardi observations.

Observations Reported

• UT Date(s): 20 May 2006 UT

  Observers: M.T. Read, T.H. Bressi

  Contact: bob at lpl.arizona.Edu

  Telescope: Spacewatch (Kitt Peak, Arizona)

  Report:

  "Magnitude is as predicted." {V 19.0}

• UT Date(s): 26, 30, 31 May, 1 June 2006 UT

  Observers: L. Barrera, H. Boehnhardt, C. Tubiana

  Data Analysis: R. Duffard

  Contact: boehnhardt at linmpi.mpg.de

  Telescope: VLT UT1

  Instrument: FORS2

  Mode: Imaging R filter, low disp. spectroscopy

  Report:

  "Visible wavelength spectra show S-type. On first night, R magnitude variability is less than 0.05 mag over about one hour. Analysis from all nights still in process."

• UT Date(s): 27 May 2006 UT

  Observers: J. Scotti

  Contact: bob at lpl.arizona.Edu

  Telescope: Spacewatch (Kitt Peak, Arizona)

  Report:

  "Magnitude perhaps fainter than predicted. Possibly due to lightcurve variation."

• UT Date(s): 28 May 2006 UT

  Observers: J. Scotti

  Contact: bob at lpl.arizona.Edu

  Telescope: Spacewatch (Kitt Peak, Arizona)

  Report:

  "3 hours of lightcurve observations"

• UT Date(s): 29 May 2006 UT

  Observers: J. Scotti

  Contact: bob at lpl.arizona.Edu

  Telescope: Spacewatch (Kitt Peak, Arizona)

  Report:

  "4 hours of lightcurve observations"

• UT Date(s): 1 Jun 2006 UT

  Observers: F. Bernardi

  Contact: tholen at ifa.hawaii.edu

  Telescope: MKO UH 2.24-m

  Report:

  "3.6 hours of BVRI photometry V(1,alpha) about 16.5. Assuming G=0.15, the phase correction is about 1.0 mag, which would make H=15.5, or 0.4 mag fainter than MPC value. Full range of V mags is less than 0.2 mag, with error of 0.03 mag per point; might be seeing two minima. Colors resemble S type (B−V = 0.84 ± 0.06; V−R = 0.49 ± 0.05)."

For more information, contact Richard Binzel (rpb at mit.edu)