Fw: [ap-gto] large donut in Ha image


david w pearson
 

anyone have any experience with large Donut in image as to where is it is occurring?
have included animation to show strange intensity variability and with features within the donut.



----- Forwarded Message ----To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Sunday, January 30, 2022, 06:29:52 PM PST
Subject: Re: Re: [ap-gto] large donut in Ha image

TPO RC-12, SBIG STF-8300m with filter wheel w 37mm filters, AP 0.67x reducer, shooting at 1700mm, off axis guider, AP1200 mount on permanent pier
group observatory, 10 min consecutive ha subs

animation link





Andrea Lucchetti
 

When I had this issue was due to a bright star slightly off the sensor field. Very common in Orion region. I saw the same with apo and newton, of course the shape changes because of central obstruction.
Andrea 

On Wed, 2 Feb 2022 at 21:29, david w pearson via groups.io <p.davidw=yahoo.com@groups.io> wrote:
anyone have any experience with large Donut in image as to where is it is occurring?
have included animation to show strange intensity variability and with features within the donut.



----- Forwarded Message ----To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Sunday, January 30, 2022, 06:29:52 PM PST
Subject: Re: Re: [ap-gto] large donut in Ha image

TPO RC-12, SBIG STF-8300m with filter wheel w 37mm filters, AP 0.67x reducer, shooting at 1700mm, off axis guider, AP1200 mount on permanent pier
group observatory, 10 min consecutive ha subs

animation link