Autore: pat69
Data: 12-02-05 16:36
In attesa di qualche risposta, nel frattempo ho trovato un'interessante
osservazione sulle doppie e filtro OIII.
Ciao
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Star: Antares
Date of Observation: 3/08/00 21UT
Location of Observation: Barraras, Salamanca, Spain
40º N, 6º W, Elev. 800 Meters.
Seeing: 6 to 7 (1 - 10, 10 best)
Transparency: 8
Limiting Mag. (naked eye): 4.5
Site classification: Rural
Instrument: Televue 101 Apo Refractor
Magnification: 180X (3mm Radian)
Separation (Clear or Touching):Clear
Magnitude Comment: Large difference in Mag according to the data
Color Comment: Light orange yellow and blue without filter. Deep orange red and blue green (turquoise) with OIII filter.
General Comment: First tried splitting Antares without the OIII filter and could not see the comes. Installed Lumicon OIII filter and the secondary became very obvious. The color of Antares changed from a light yellow orange to a deep orange red and the secondary was a blue green (turquoise). The filter also gave a size relationship. Antares was large with the small secondary sitting along side like a plum along side a large apple or orange. The colors were startling with the filter. I then tried again without the filter and I would notice a hint of blue that would pop out of the light yellowish orange primaray when the seeing would settle down for an instant. I don't remember who suggested the OIII filter but it is a winner in these situations with doubles that have a great difference in Magnitudes and very close components. The biggest surprise was the intense color change. Going back and checking the 22 messages it looks like I have to thank PJ Anway for the OIII filter tip.
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Patrizio
Celestron CGE 1400 XLT, Meade LX90 EMC
42°19'N, 13°19'E (AQ)
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