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Undoubtedly the most successful observation from this region in the last 12 months with 5 well timed positives and 2 misses !
View the updated prediction.
Observers: 1 D Gault, Goulburn, NSW, Australia 2 A Brakel, Gunning, NSW, Australia 3 M Nelmes, Spence, ACT, Australia 4 P Purcell, Red Hill, ACT, Australia 5 D Herald, Cooma, NSW, Australia 6 B Loader, Darfield, New Zealand 7 D Watson, Whakatane, New Zealand (off Plot below) 8 Predicted
The Google Earth picture below shows the location of the observers in Australia with the predicted path.
Discussion:
The ellipse above is plotted at the best fit size of 216.2 by 229.4 km as calculated by Occult 3.6. This agrees well with the expected diameter 229 km of Bamberga. With five chords we have a high confidence in the path for this event. The longest chord measured 14.6 seconds which agrees well with the predicted 14.9 secs.
Observational Data:
TELESCOPE DETAILS:
Observer's Name : Dave Gault
Aperture (cm) : 20
Focal length (cm) : 200 with f3.3 focal reducer
Type (e.g. SCT; Newtonian) : AltAz SCT
Magnification : N/A
Observing site name : FrenchVC rest area, Goulburn
Longitude (DD MM SS ; East +ve) : 149 38 29.4
Latitude (DD MM SS ; South -ve) : -34 47 12.9
Height above Sealevel (metres) : 701.6
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : WGS84
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions :
Time Source (e.g. WWVH, GPS) : GPS-KIWI
Recording method (e.g. tape) : Video
Could you see the Asteroid? : NO
Approx. Limiting Magnitude : Not sure
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 8:28
Star and Object Merged : not sighted
Disappearance At : 8:32:36.46 0.0 0.02 4 frames
Reappearance At : 8:32:47.66 0.0 0.02 4 frames
Star and Object Separated :
Stopped Observing : 8:39
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : N/A
ADDITIONAL COMMENTS:
Star took 4 frames (0.16 seconds) to disappear and reappear.
See attached light curve below.
The time chosen was for the frame closest to the 50% level as I assumed
stellar diameter rather than diffraction was the main influence.
Dave Herald did send me his plot which did show a similar slow event but alas I didn't keep it.
Dave's video can be seen on YouTube...
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TELESCOPE DETAILS:
Observer's Name : Albert Brakel
Aperture (cm) : 20 cm
Focal length (cm) : 200 cm
Type (e.g. SCT; Newtonian) : SCT
Magnification : 77x
Observing site name : 23.1 km N of Gundaroo
Longitude (East +ve) : 149 14' 28"
Latitude (South -ve) : -34 50' 05"
Height above Sealevel (metres) : 619 m
Geodetic Datum (e.g.WDD84,NZ1949): AGD1966
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): Last stage of astronomical twilight, clear sky
Time Source (e.g. WWV, VNG) : USNO on internet via Dimension4 software & beeper box
Recording method (e.g. tape) : Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : >10
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 08:27
Disappearance At : 08:32:35.9 0.6 PE applied. Sudden.
Reappearance At : 08:32:49.1 0.4 PE applied. Sudden.
Stopped Observing : 08:37
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : Yes
If YES, state value : 0.6 and 0.4 sec
ADDITIONAL COMMENTS:
Excellent definite occultation in good conditions. If only they could all be like this.
_____________________________________________
TELESCOPE DETAILS:
Observer's Name : Mike Nelmes
Aperture (cm) : 10 (x 2)
Type (e.g. SCT; Newtonian) : Binoculars
Magnification : 25x
Observing site name : Mt Rogers (backyard) Observatory, Spence ACT
Longitude (DD MM SS ; East +ve) : +149 03 30.6
Latitude (DD MM SS ; South -ve) : -35 11 39.8
Height above Sealevel (metres) : 653
Geodetic Datum (e.g.WGS84,NZ1949):
Height Datum (if known) :
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): Evening twilight
Time Source (e.g. WWVH, GPS) : Beeper box synchronised to Dimension 4
Recording method (e.g. tape) : Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : 10
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 08:30:00 N/A N/A
Disappearance At : 08:32:34.2 PE 0.25s
Reappearance At : 08:32:48.75 PE 0.5s
Stopped Observing : 6:33:00
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : No
_____________________________________________
TELESCOPE DETAILS :
Observer's Name : Patrick Purcell
Aperture (cm) : 40cm
Focal length (cm) : 2000cm
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : 70x
Observing site name : Red Hill, ACT
Longitude (DD MM SS ; East +ve) : 149 06 51.8
Latitude (DD MM SS ; South -ve) : -35 19 30.6
Height above Sealevel (metres) : 733m (using Garmin 12 GPS)
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : ?
Sky Transparency (Delete two) : Poor
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): Twilight; obtrusive smoke haze; no clouds; breeze from East.
Time Source (e.g. WWVH, GPS) : Beeper box manually synchronised via Dimension4
Recording method (e.g. tape) : Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : ?4 unaided; probably 8.5 with scope
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 08:30:00
Star and Object Merged : Asteroid NOT seen
Disappearance At : 08:32:33.7 slightly late (?0.6s)
Reappearance At : 08:32:48.1 (PE 0.4s NOT applied)
Star and Object Separated : Asteroid NOT seen
Stopped Observing : 08:33:15
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : No
ADDITIONAL COMMENTS:
Very difficult to locate the star under the prevailing conditions.
_____________________________________________
TELESCOPE DETAILS:
Observer's Name : Dave Herald
Aperture (cm) : 20
Focal length (cm) : 200
Type (e.g. SCT; Newtonian) : SCT
Observing site name : Cooma
Longitude (DD MM SS ; East +ve) : 149 09 44.8
Latitude (DD MM SS ; South -ve) : -36 14 18.6
Height above Sealevel (metres) : 835
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.):
Time Source (e.g. WWVH, GPS) : GPS
Recording method (e.g. tape) : Video
Could you see the Asteroid? : No
Approx. Limiting Magnitude :
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing :
Disappearance At : 08 32 27.95 .04
Reappearance At : 08 32 41.48 .04
Stopped Observing :
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : NA
_____________________________________________
TELESCOPE DETAILS:
Observer's Name : Brian Loader
Aperture (cm) : 25.4
Focal length (cm) : 250
Type (e.g. SCT; Newtonian) : SCT
Magnification : n/a
Observing site name : Darfield
Longitude (DD MM SS ; East +ve) : +172° 06' 24.4" E
Latitude (DD MM SS ; South -ve) : -43° 28' 52.9" S
Height above Sealevel (metres) : 210
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.):
Time Source (e.g. WWVH, GPS) : GPS/KIWI
Recording method (e.g. tape) : VIDEO
Could you see the Asteroid? : no
Approx. Limiting Magnitude : 11
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 08:27
Stopped Observing : 08:34
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : n/a
List all Interruptions to Observing: nil
ADDITIONAL COMMENTS: no event observed
_____________________________________________
TELESCOPE DETAILS:
Observer's Name : Diana Watson
Aperture (cm) : 20
Focal length (cm) : 200
Type (e.g. SCT; Newtonian) : Celestron 8
Magnification : 80 times
Observing site name : Whakatane
Longitude (DD MM SS ; East +ve) : 176 51 50.7
Latitude (DD MM SS ; South -ve) : -37 55 18.5
Height above Sealevel (metres) : 2.8 metres
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) :
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Fair
Other Conditions:
(Wind, Clouds, Lights, etc.): moisture and fire haze
Time Source (e.g. WWVH, GPS) : WWVH
Recording method (e.g. tape) : tape recorder
Could you see the Asteroid? : No
Approx. Limiting Magnitude : 13
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 08:24:00.0
Stopped Observing : 08:35:00.0
ADDITIONAL COMMENTS:
Thought I should be able to see the asteroid, but unable to.
The target star was not too steady, tending to flare,
maybe due to the burn off smoke haze plus moisture in the air.
_____________________________________________
Well done team!
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