Occultation by Triton (2017-10-05)

Occultation map Occultation circumstances Sky Map Interactive Google Map Links History

Important : If you plan to observe, please download and read the protocol in order to prepare the observation. It will help us to standardise the post-treatment. If you succeed in the observation, please fill the report (pdf, docx, odt) and follow the instructions.

Occultation map

Information about the map:

Occultation circumstances

Object Triton
Size (km) 2820 (including atmosphere)
Date (TU) 2017-10-05 23:51:37
Star position 22 54 18.4364 -08 00 08.318
Stellar catalogue release of three preliminary Gaia DR2 stellar positions
Proper motion μRA*=27.51mas/yr, μDE=-1.82mas/yr
Object position 22 54 18.4336 -08 00 08.127
Ephemeris JPL DE435+nep081 + offset (RA* = 7.8mas; DEC = -17.6mas)
C/A 0.195
P/A 347.51
velocity (km/s) -16.793
Geocentric distance Δ (au) 29.082
G mag* 12.2
J mag* 11.2
Note: Offset for Triton's ephemeris was determined by Marcelo Assafin (Observatorio de Valongo) and his colleagues (Observatorio Nacional de Rio de Janeiro) with 8 nights of observations during 15-23 September using a release of 119 and 334 preliminary Gaia DR2 stellar positions.

Sky map (Aladin)

link to sky-map

Interactive Google Maps

The red line represents the centrality of the occultation. The green lines represent the half-light level where the star's flux will be reduced by 50%. The blue lines are the 1% stellar drop (the theorical limit of detection of the occultation).
Each red pin is spaced by one minute and indicates the mi-time of occultation on the central path. The path goes from East to West.
By clicking on one place, you will have an infobox with : Note that the uncertainty of the event is estimated to be about 60km in distance and about 8sec in time.

Useful links

The following websites may be useful to prepare the occultation's observation:

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