Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 05/26/2022 - 12:02
The AAVSO maintains AAVSOnet, a set of robotic telescopes located around the world, many in pristine locations. These include systems from a Televue NP101 refractor to several 24-inch (61cm) telescopes. You have access to Spectrum Analyzer diffraction gratings for low-resolution spectroscopy; an eShel spectrograph; Sloan as well as Johnson/Cousins filters; a diffuser for bright, high precision photometry, neutral density filters for bright targets, etc. We welcome submissions from beginners wanting to learn about photometry, observers wanting to participate in AAVSO Alert campaigns, advanced photometrists, and the general member community. Please see
https://www.aavso.org/aavsonet
for information and proposal submission forms.
Arne
Hi Arne,
you mentioned in your post that some AAVSOnet scopes have neutral density filters for bright star photometry. Where in the imaging train are these placed?
I am thinking of using a full aperture photographic ND filter in front of my 4" refractor, or perhaps a smaller ND filter in a manual filter tray in front of a filter wheel. Which would you recommend?
Where were the AAVSOnet ND filters sourced from? Cheers,
Mark
I believe, but may be incorrect, that Arne's note was about older configurations of systems. Presently I do not believe there are any diffuser or ND filters available on AAVSONet systems.
Filters are all near focus in filter wheels.
Be careful with the optical quality of any over-objective filters. Its a lot easier to make small 1.25" or 2" flat filters than 4"+ filters!
Peter
BPEC
Hi Peter,
I agree, 1.25" or 2" filters would be better, and probably cheaper. I'll need to buy a manual filter draw as well. Cheers,
Mark
BSM_NH2 has a dual filter wheel configuration that offers some 33 filters!
B,V,R,I,SU,SG,SR,SI,ZS,C,D,STY,
Bdiff,Vdiff,Rdiff,Idiff,SGdiff,SRdiff,SIdiff,
Bnd09,Vnd09,Rnd09,Ind09,SGnd09,SRnd09,SInd09,
Bnd18,Vnd18,Rnd18,Ind18,SGnd18,SRnd18,SInd18
diff is with the diffuser added, and there are two ND addons available. I've forgot the specs on the nd09 and nd18
If you want to experiment you may submit a proposal to the AAVSOnet; we're eager to have people try them out!
George
Good to know George! You could have told me when I made the AAVSONet scope matrix a few months back. Any more systems with 2 filter wheels??
Peter
Sorry about the confusion, Peter.
The latest information on the AAVSOnet scopes is available at https://app.aavso.org/aavsonet/telescopes2/?&active=true
We will soon (this month) updates to the AAVSOnet webpages that will show this current information.
George
How do I open that…
George,
How do I open that file with formatting? All I get is a page of oddly (to me) formatted test.
Peter
Peter,
The data from https://app.aavso.org/aavsonet/telescopes2/?&active=1 you can add a scope name: &name=bsm_nh2
It is a raw dump in json format, almost but not really a report. You can screen scrape ( Ctrl-a, Ctrl-c ) and paste to a text editor (Ctrl-v)
What are you looking for?
George
Thanks George,
I'll think about submitting a proposal to use the ND filters on BSM_NH2, but it may not be suitable for the southern objects I am observing. Cheers,
Mark