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Observation by Alex Pratt: Lunar occultation of double star SAO 164...

Uploaded by

Alex Pratt

Observer

Alex Pratt

Observed

2017 Oct 29 - 19:26

Uploaded

2017 Nov 02 - 21:01

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Constellation

Grus

Field centre

RA: 22h41m
Dec: -46°51'
Position angle: +179°03'

Field size

0°07' × 0°04'

Equipment
  • C11 @ f/10
  • Watec 910 video camera
  • Losmandy G11 mount
  • IOTA-VTI GPS video time inserter
Exposure

1/50th sec exposures

Location

Z92

Target name

SAO 164809

Title

Lunar occultation of double star SAO 164809

About this image

In the Occult4 prediction for this event it lists the star as mag 7.6 (component A mag 7.67, component B mag 10.17) with a double star step duration of 0.7 sec.

Analysis of the video using Limovie gives estimated mags of 7.8 and 9.4, with a step of 0.459s. The data in the Interferometric Catalogue (all from 1991) give estimates of 7.7 - 8.1 and 9.5 - 10.4, respectively.

Tim Haymes also recorded this occultation from Reading, a baseline of ~200 miles, so we're hopeful that if we have favourable lunar limb geometry we can derive the PA and separation of this close double (1991: 50 degrees and 0.4"). 

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