FINAL UPDATE: 14 Jun 2012 - 14:38 UT:

This is a summary of reported results at the above time.

• Rockhampton, QLD: Steve Kerr. 0.3m (Watec-120N, GPS, DVR)
  • I had quite good conditions here for the Pluto event. Detailed monitoring from 11:15 to 11:30 UTC shows a featureless light curve much as expected for this location. The start was a little later than I wanted ... spent too much time taking pictures of the lunar eclipse, got to the Pluto field and then decided to change up to f/7 to get some seperation from that nearby star and then the mirror kept flopping out of focus after the big shift from f/4 ... Tangra had some trouble hanging onto the field at the end of the run ... no idea why.
  • 

• Samford Valley, QLD: Jonathan Bradshaw. 0.35m. (G-Star, GPS, DVR)
  • Nothing to report except the moon has come out to play and looks great!

• Toowoomba, QLD: Leslie Young (SwRI), Larry Wasserman (Lowell) on the Mt Kent 0.5m (Frame transfer camera)
  • "Pea soup" fog. No result.

• Siding Spring, NSW: Eliot Young (SwRI), Josh Walawender on the 4.0m AAT (Frame transfer camera)
  • (No info)

• Siding Spring, NSW: Federica Bianca on the 2.0m Faulkes Telescope South. (Paris Observatory)
  • (No info)

• Auckland, NZ: Harold Reitsema and Grant Christie on either the 0.5m Zeiss or 0.4m scope. (Frame transfer camera)
  • Clear and data obtained. No occultation.

• Auckland, NZ: Jennie McCormick at Farm Cove Observatory
  • Data obtained. No occultation.

• Hawkesbury Heights, NSW: Dave Gault (Watec 120N, GPS, DVR)
  • The atmosphere was clear at Hawkesbury Heights, but the stability was terrible, which limited the mag. to about 13. and occasional local gusts of wind brought this down to about 10. No hope to see mag. 15 anything.

• St Clair, NSW: Hristo Pavlov (Watec 120N, GPS, DVR)
  • I observed from St Clair. The athmosphere was very bad but Pluto was bright enough for my system. Looking at my data (from 11:17 to 11:23) it seems that I have a miss but because of the bad atmosphere a very shallow event may be buried in the noise. On the light curve below green is Pluto, pink is a comparison star. Light curve is not normalized.
  • 

• Werrington, NSW: Tony Barry (Watec 120N, GPS, DVR)
  • Sky clear, turbulence a bit too high, equipment issues. On target field about an hour ahead of time; at 4 minutes before expected D (11:20 UT), recorder shut down. Changed and was up again at 4 minutes after expected D. Recorded till 11:35 UT. Due to atmospheric conditions, I do not know if the recording is usable. Will consult with Dave G and advise.

• Martinborough, NZ: Peter Graham (Watec 120N, GPS, DVR)
  • Had reasonably good conditions from 11:10 to 11:25. Field was identified and recorded but the camera gain was set too low to give a good SNR on the target. Data supplied to Marc Buie and Bruno Sicardy for further analysis. Peter's observatory is about 20km north of Wellington (perpendicular to the track) where a shallow atmospheric occultation was seen. Whether this means he was close enough to capture a very shallow event remains to be seen.

• CNO Observatory, Wellington, NZ: Roland Idaczyk (KPC Video, GPS)
  • Unable to observe.

• Carter Observatory, Wellington, NZ: Marc Buie (SwRI), Graham Blow, Gordon Hudson. 0.41m B & C. (Frame transfer camera)
  • Success at Carter with a clear shallow atmospheric occultation centred at 11:16:53 - slightly earlier than expected - with a duration of ~44 sec and drop in flux of 0.03.

• Blenheim, NZ: 0.6m Bootes-3 telescope operated remotely from Spain
  • Data obtained but unlikely to be of high enough quality to be used.

• Darfield, NZ: Brian Loader (Watec 120N, GPS, DVR)
  • No result. The expected spell of atrocious winter weather looks to be building up this evening and set to last until after the transit for most parts.

• Mt John, NZ: Joel Parker (SwRI), Bob Howell (U.Wyoming) on 2 x 0.61m (Frame transfer cameras)
  • No result. Clouded out.

• Tasmania Portable: Paris Group?
  • (No Info)

• Hobart, TAS: Felipe Braga-Ribas (LESIA, Observatoire de Paris) on the 1.0m
  • No observations from Canopus Observatory from University of Tasmania at Hobart. After a blue sky day, at the night the sky is completely covered and with light rain.

• Dunedin, NZ: Ross Dickie, Ash Pennell on the 0.35m Beverly-Begg. (Watec 120N, GPS, DVR)
  • No result. Clouded out.

UPDATE: 3 Jun 2012 - 12:52 UT:

• Dave Gault reinforces that it is most important that observations of Pluto and the star are made while they are well separated, so that the individual flux from each object can be unambiguously determined. If you're doing this on nights before or after the event the observations should be carried out at about the same air mass (time of night) as the event occurs and through exactly the same observing setup as you use for the occultation.

• Mark Buie recommends that owing to the uncertainty in the time of the event that observing be carried out for at least 10 minutes either side of the predicted time.

• As per Marc's update of 30 May below, the star is substantially brighter in the I band than in white. So using any red filter is going to be advantageous in improving the S/N. Plus, the further red you go, the more blue monlight will be filtered out.

• Don't forget that this event occurs during a partial lunar eclipse with mid-eclipse (37%) at 11:03 UT. (The occultation time is about 11:19-11:20.)

• The SwRI Wiki for this event is available here.

• Data is being shared between the Lowell/SwRI and Paris groups.

• Rockhampton, QLD: Steve Kerr. 0.3m (Watec-120N, GPS, DVR)
• Samford Valley, QLD: Jonathan Bradshaw. 0.35m. (G-Star, GPS, DVR)
• Toowoomba, QLD: Leslie Young (SwRI), Larry Wasserman (Lowell) on the Mt Kent 0.5m (Frame transfer camera)
• Siding Spring, NSW: Eliot Young (SwRI), Josh Walawender on the 4.0m AAT (Frame transfer camera)
• Siding Spring, NSW: Federica Bianca on the 2.0m Faulkes Telescope South. (Paris Observatory)
• Auckland, NZ: Harold Reitsema and Grant Christie on either the 0.5m Zeiss or 0.4m scope. (Frame transfer camera)
• Hawkesbury Heights, NSW: Dave Gault (Watec 120N, GPS, DVR)
• St Clair, NSW: Hristo Pavlov (Watec 120N, GPS, DVR)
• Werrington, NSW: Tony Barry (Watec 120N, GPS, DVR)
• Martinborough, NZ: Peter Graham (Watec 120N, GPS, DVR)
• CNO Observatory, Wellington, NZ: Roland Idaczyk (KPC Video, GPS)
• Carter Observatory, Wellington, NZ: Marc Buie (SwRI), Graham Blow, Gordon Hudson. 0.41m B & C. (Frame transfer camera)
• Blenheim, NZ: 0.6m Bootes-3 telescope operated remotely from Spain
• Darfield, NZ: Brian Loader (Watec 120N, GPS, DVR)
• Mt John, NZ: Joel Parker (SwRI), Bob Howell (U.Wyoming) on 2 x 0.61m (Frame transfer cameras)
• Tasmania Portable: Paris Group?
• Hobart, TAS: Felipe Braga-Ribas (LESIA, Observatoire de Paris) on the 1.0m
• Dunedin, NZ: Ross Dickie, Ash Pennell on the 0.35m Beverly-Begg. (Watec 120N, GPS, DVR)

UPDATE: 30 May 2012 - 04:48 UT:

Marc Buie advises:

• Eliot Young was on AAT last night and was able to get some test observations. Using an I-band filter the star was twice as bright as Pluto. That's pretty decent and somewhat better than expected. I expect anyone trying this would be well advised to work as far to the red as they can. The star is quite a bit redder than Pluto and the scattered light from the Moon will be worst in the blue. I will be testing two choices, no filter at all and using an I-band filter. I expect the I-band filter will be the winner.

INTRODUCTION:

At around 11:19 (NZ) and 11:20 (AUS) UT on 2012 June 4 Pluto will occult a mag 14.9 (in R) star in Sagittarius. The event may be visible from much of New Zealand and the south-east of Australia (although at low altitude).

Observations of this important event are required by both Larry Wasserman at Lowell Observatory and Bruno Sicardy at Paris Observatory. However because of the faintness of the star and planet, telescopes of at least 35cm aperture are likely to be required, along with an image acquisition system such as a Watec 120N integrating video camera.

Observers from Australia and New Zealand have a history of co-operation with astronomers at both Lowell and Paris Observatories. While (to our knowledge) no observers from Paris will be in attendance on this occasion, several observers from Lowell and the SouthWest Reasearch Institute will be making the trip out with portable observing rigs. They plan to observe from Wellington (Carter Observatory), Lake Tekapo (Mt John Observatory), the AAT, Tasmania, and elsewhere. It is very desirable that these observations be augmented with those from advanced amateurs in the region with suitable equipment.

UPDATES:

The map below from Bruno Sicardy at Paris Observatory shows his update of the path as at 18 May.

Dark gray is night and light gray is astronomical twilight (Sun at less than 18° below the horizon). The planet's shadow moves from right to left, and each red dot is separated by one minute. The nominal occultation time (big red dot on the map) is for closest approach at 11:16:30 UT.

The two following graphics show the region of visibility as supplied by Larry Wasserman at Lowell Observatory on May 9. Larry comments that the first graphic is an early one in which all the magnitudes except for the star mag (14.86) should be ignored. The second mercator plot is a prediction based on an early release of the UCAC4 catalogue. Given that the uncertainty is at least a Pluto radius, they're the "same".

Larry also comments that the biggest problems observing this one are going to be the crowded field, a full moon only 25 degrees away, and the relative faintness of the star.

STAR AND OCCULTATION DETAILS:

Star J2000 coordinates:
RA   18 36 45.928
DEC -19 16 17.753

Star coordinates as of Date:
RA    18 37 32.259
DEC  -19 15 31.847

Star R mag: 14.8
Star K mag: 7.6
Magnitude drop in R: 0.43
Max. duration: 73 sec

CHARTS:

The following charts are drawn from the Paris Observatory page which should be visited for further updates prior to the event.

20 x 20 arcmin

5 x 5 arcmin

OTHER IMPORTANT DETAILS: