A Two 4 second occultations were recorded by Chris Chad from the same station, using video OSD technique.

Two clearly observed misses were recorded for this event.

View the updated prediction.

Observers:
  1    C Chad,Gunnedah, NSW
  2    C Chad,Gunnedah, NSW
  3(M) J Broughton,Reedy Creek, QLD, AU
  4(M) P Anderson, Gap, Brisbane, Queensland
  5(P) Prediction, 4 July


        

Discussion:

The circles above are plotted at the expected 58 km diameter of Valeria.

Despite two effective chords it is not possible to determine whether Chris was north or south of the central line of the event as there are 4 possible solutions the the relative positions af Veleria to the two stars.

The figures below show the two extreme sceanrios and the other two (as above) are if the stars were exactly alined to the path in which case they could be either side.

The figure below shows the Tangra light curve of Chris' occultation.

The possiblity of a binary asteriod was also considered but the different magnitude drops points to this being a new double star discovery.

This result has been written up for publication in Journal of Double Star Observing (JDSO) and has been accepted - it is expected to appear in the January edition.

Observational Data:

Observation details for MP ( 611 ) Valeria
By Star              UCAC2 30429828
On 2013-08-15  at 11:51:44.0

_______________________________

Observer   Chris Chad
Location   Gunnedah, NSW
Longitude  +150:15
Latitude   -30:59
Altitude   315 m
Datum      WGS84
Telescope Newtonian
Aperture   25 cm
Seeing     Steady Clear
Camera Type  Samsung SCB-2000             NTSC/EIA
Camera Delay 0
Timing     GPS - time inserted Video with frame analysis
Disappearance  11:51:17.33
Reappearance   11:51:20.83
Comments: Two events observed.  First event very clear, but early & a lower
magnitude drop than expected. Second event less clear, but very certain.
Lower magnitude drop than first.  Excellent observing conditions.
Frame delay (0.034s) subtracted from times.

_______________________________

Observer   Chris Chad
Location   Gunnedah, NSW
Longitude  +150:15
Latitude   -30:59
Altitude   315 m
Datum      WGS84
Telescope Newtonian
Aperture   25 cm
Seeing     Steady Clear
Camera Type  Samsung SCB-2000             NTSC/EIA
Camera Delay 0
Timing     GPS - time inserted Video with frame analysis
Disappearance  11:52:11.68
Reappearance   11:52:15.79
Comments: Two events observed.  First event very clear, but early & a lower
magnitude drop than expected. Second event less clear, but very certain.
Lower magnitude drop than first.   Excellent observing conditions.
Frame delay (0.034s) subtracted from times.

_______________________________

Observer   Peter Anderson
Location   The Gap, Brisbane, Queensland
Longitude  +152:55
Latitude   -27:27
Altitude   171 m
Datum      WGS84
Telescope Newtonian
Aperture   41 cm
Seeing     Slight flickering Clear
Camera Type  Visual         Other
Camera Delay 0.5
Timing     Radio broadcast - calibrated Visual, PE applied

Missed

Comments: ID was difficult, but reasonably confident. Star mv 12.0 in bright
moonlight was still well held and any event longer that 0.25sec would have
been detected As usual used WWVH supported by stopwatches,
tape recorder and 'eye & ear' method

_______________________________

Observer   John Broughton
Location   Reedy Creek, QLD, AU
Longitude  +153:23
Latitude   -28:06
Altitude   66 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   25 cm
Seeing     Steady Clear
Camera Type  WAT120N+       PAL/CCIR
Camera Delay 0.11
Timing     GPS - time inserted Video with frame analysis

Missed

Comments: