[vsnet-survey 71] (fwd) [vsnet-chat 4940] RES: (fwd) Finding the right focal lenght for Novae Search

[Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>]

From: Cristovao Jacques Lage de Faria <Cristovao@agnet.com.br>
Date: Wed, 12 Dec 2001 16:40:08 -0200
Subject: [vsnet-chat 4940] RES: (fwd) Finding the right focal lenght f
	or Novae Search

Arne,


I have already done a research on Novae discovered since 1995, in order to
select the regions to be scanned and also to know ans average magnitude.
Most of the galatic novae occur in the 7th to 8th magnitude range. WIth this
information and with our experiences, I think that a 100mm Fl will be pretty
fine for  both Limiting magnitude and  coverage area criteria.

Thanks for your comments.

Regards,
Cristovao Jacques
Wykrota Observatory - CEAMIG 
Belo Horizonte - BRAZIL

-----Mensagem original-----
De: aah@nofs.navy.mil [mailto:aah@nofs.navy.mil]
Enviada em: quarta-feira, 12 de dezembro de 2001 14:25
Para: vsnet-chat@kusastro.kyoto-u.ac.jp
Assunto: [vsnet-chat 4939] Re: (fwd) Finding the right focal lenght for
Novae Search


Cristovao Jacques wrote, regarding Nova searching:
>Increasing the focal length we gain in
>magnitude but we loose in field coverage, so what will be the best FL.
>Do you also recomend any kind of filter?
  I would worry a bit about source confusion at 10th magnitude
in the heart of the Milky Way with 70arcsec pixels.  You may not
be able to uniquely identify novae until they get quite a bit
brighter.  There is always a tradeoff between depth and field
coverage, and how you choose depends on how bright you think a
typical nova will be when you can detect it.  Perhaps some
research into the nova discoveries over the past decade would help.
  If you want to use a filter, I'd recommend R.  It matches the
peak response of the CCD and also includes Halpha, a very strong
emission line in most novae.  However, many telephoto lenses will
have to be refocussed once you get into the red.
Arne

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