Observations from Dark Sky Observatory, North Carolina - New 2007 Mar. 20, 0h UT
The light curve indicates no occultation occurred between 10:45 and 11:00 UT
MessageFrom: Daniel B Caton [catondb@appstate.edu] Sent: Monday, March 19, 2007 6:29 PM To: Dunham, David; 'Derek C Breit' Cc: 'David Dunham'; 'Joe Pollock'; 'DeeMuenchen Wolfgang Beisker'; EXT Young, Leslie; 'CO Boulder SWRI Alan Stern'; 'C KS Eskridge FarpointObs Gary Hu'; 'MOiBlue Springs Bob Sandy'; 'L CO Springs Brian Warner' Subject: RE: Pluto non-event? - probably north shift Attachment: Light curve plot David et al. Here is a quick reduction plot, magnitude vs. observation number ("row index"), all observations evenly spaced about 10 seconds apart. They start at UT 10:45:19 through 11:00:05 start times. Yes, it was well into twilight and there is a lot of scatter, but no apparent event. These data were dark-subtracted, flat-fielded and aperture-photometered using the star just to the west of Pluto as the comparison. Maybe any atmospheric event is lost in the scatter. Joe Pollock had scatter apparently due to clouds at the end of his run. Dan Daniel B. Caton Professor and Director of Observatories Dept. of Physics and Astronomy Appalachian State University Boone, NC 28608 (828) 262-2446 (fax -2049) catondb@appstate.edu www.DanCaton.Physics.Appstate.edu www.DanCaton.Physics.Appstate.edu -------------------------------------------------------------------------------- From: Dunham, David [mailto:David.Dunham@jhuapl.edu] Sent: Monday, March 19, 2007 6:18 PM To: Daniel B Caton; Derek C Breit Cc: David Dunham; Joe Pollock; DeeMuenchen Wolfgang Beisker; EXT Young, Leslie; CO Boulder SWRI Alan Stern; C KS EskridgeFarpointObs Gary Hu; MOiBlue Springs Bob Sandy; L CO Springs Brian Warner Subject: RE: Pluto non-event? - probably north shift Dan, Most of the few successful observers that I know of have not reduced their observations, but one has, Brian Warner at Palmer Divide Observatory in Colorado. He had an occultation, but it was apparently short, like he was near one of the limits (he had a nearly "central" duration, but almost all of it was a gradual decline followed by an equally gradual rise, so I think it was mostly by the atmosphere rather than the solid part of Pluto; I'll post his light curve on my Web site soon). He was over 1000 km north of you relative to the path (that's over 500 km in the sky plane). So your observation indicates that he was probably near the southern limit. It's amazing that you were able to get any useful observations so far east; at the closest approach time for you of 10:55.4, the Sun alt. was -8 deg. Brian Warner's observation shows that the occultation was 4.6 min. late, so the closest approach time was 11:00.0 for you, so the presence or absence of any dimming of the star in the last part of your recording that you might be able to discern will be of great interest. Your observatory was 744 km south of the central line as defined in my combined prediction system. David -------------------------------------------------------------------------------- From: Daniel B Caton [mailto:catondb@appstate.edu] Sent: Monday, March 19, 2007 5:52 PM To: 'Derek C Breit' Cc: 'David Dunham'; Dunham, David; Joe Pollock Subject: RE: Pluto non-event? Derek- Thanks for the reply. Do you have any positive results reported? We had a miss at our campus observatory as well, where my colleague Joe Pollock was working, although both our sites are nominally along the same event line. Dan Daniel B. Caton Professor and Director of Observatories Dept. of Physics and Astronomy Appalachian State University Boone, NC 28608 (828) 262-2446 (fax -2049) catondb@appstate.edu -------------------------------------------------------------------------------- From: Derek C Breit [mailto:breit_ideas@hotmail.com] Sent: Monday, March 19, 2007 5:47 PM To: 'Daniel B Caton' Cc: David Dunham; david.dunham@jhuapl.edu Subject: RE: Pluto non-event? Dr Caton- I am not the one to ask, though you are the first to suggest a miss that I know of.. Dr David Dunham is.. I have CC'd him and eagerly await his response to this.. I know one thing.. Your data is going to be quite valuable, as many places were subjected to bad weather.. Nice Going! Derek BREIT IDEAS Obs - http://www.poyntsource.com/New/index.htm Western USA - http://tech.groups.yahoo.com/group/IOTA-West/ IOTA listserver - http://groups.yahoo.com/group/IOTAoccultations/ IOTA Website - http://www.lunar-occultations.com/iota/iotandx.htm -----Original Message----- From: Daniel B Caton [mailto:catondb@appstate.edu] Sent: Monday, March 19, 2007 2:27 PM To: breit_ideas@hotmail.com Subject: Pluto non-event? Derek- I tried the Pluto occultation from our Dark Sky Observatory, taking 5-second R-band CCD exposures at 10-second intervals (defined by the CCD readout time), with our 32-inch telescope, from about 10:45 UT - 11:00 UT. The photometry yielded no event. I presume there was a "miss"? Dan Daniel B. Caton Professor and Director of Observatories Dept. of Physics and Astronomy Appalachian State University Boone, NC 28608 (828) 262-2446 (fax -2049) catondb@appstate.edu www.DanCaton.Physics.Appstate.edu