Stellar occultations
Triton occultation yellow alert
On 2003 November 29, there is a possibility of a Triton occultation
observable from Hawaii and California. The event is described
at the
MIT occultation page,
http://occult.mit.edu/research/occultations/Triton/Tr266.html
with maps at Bruno Sicardy's 2003 occultation page
http://despa.obspm.fr/~sicardy/triton/triton.html
As usual with occultations by small, outer-solar system bodies, the
maps only show the current predicted location of the shadow. This
can change dramatically depending on refinements to the star's position.
If the event is observed from Hawaii and California, we can
continue to track the changes in Triton's atmosphere. But this
event may be difficult to observe; it occurs just after sunset
in Hawaii, and at high airmass in California (3.2 at Lick, 2.3 at Palomar).
Star= GSC 6348-476, or USNO-A2.0 0675-35937787
DATE & TIME = 2003 November 29 3:45:59.36 (UT)
RA: 20 52 45.9017 Dec: -17 33 34.365 (Ron Stone)
V = 13.4 (V) (Ron Stone)
This star is not in 2MASS, and no accurate colors are found in Vizier
for spectral typing.
The star is in the USNO-A2.0 (0675-35937787) with B=13.5, R=12.7,
but USNA-A2.0 magnitudes are often poor.
Leslie Young and Will Grundy measured J = 12.1 K = 11.6 with
an accuracy of probably about 0.2 mag, so this star
is somewhere between a G8 (V-K=1.63, T=5490) and K0 (V-K=1.83, T=5240).
This doesn't jibe well with the USNO mags though, since
USNO gives B-R = 0.8 (cf. B-R=1.3 for G8, 1.5 for K0).
For Hawaii, it is also important to concider sky backgorund.
This report from Gemini
estimates a brightness of 9.9 mag/square arcsec at zenith with
the sun 1 deg above the horizon, or 14.5 mag/pix on SpeX/Guidedog (0.12 arcsec pixels).
Leslie Young and Jim Elliot have
proposed to IRTF for this event, and were awarded time.
Other possible sites include Haleakala or Palomar.
Observers and other interested parties:
Jim Elliot (jle@mit.edu),
Michael Person (mjperson@MIT.EDU),
Cathy Olkin (colkin@alum.mit.edu),
Kurt Retherford (kretherford@swri.edu),
Lewis Roberts (Lewis.Roberts@Maui.AFMC.AF.MIL),
Scott Severson (severson@ucolick.org),
Bruno Sicardy (sicardy@despace.obspm.fr) ,
Rem Stone (rem@ucolick.org),
Ron Stone (rcs@nofs.navy.mil),
Thomas Widemann (thomas.widemann@obspm.fr),
Leslie Young (layoung@boulder.swri.edu)
Send mail to 2003 Nov 29 Triton list
A list of potential sites is:
Location Observers Instrument
-------- --------- ---------- ----------------------------------------
Lick Nickel Olkin/Rem Stone Guide camera Cancelled due to altitude limits
Haleakula
IRTF Young/Retherford SpeX
CFHT Widemann Megacam
Last updated 2003 Nov 25 by Leslie Young,
layoung@boulder.swri.edu ,
http://www.boulder.swri.edu/~layoung