Sat, 06/21/2014 - 20:57
I attended the SAS (Society for Astronomical Science) meeting last week in Ontario, California. This was a joint meeting between, SAS, AAVSO and CBA. There were about 160 attendees. There were workshops and two days of presntations. Arne gave a nice talk at the banquet on Saturday night. I submitted a paper and did a presentation on the Orion Project. Ontario, California is not exactly an astronomical mecca, but the hotel was nice and the meeting went well. For those interested I have posted some pictures from last week on the Orion Project web site. They can be viewed at http://www.hposoft.com/Orion/SAS14.html
Jeff (HPO)
Hopkins Phonix Observatory
To: Jeff,
Great pictures! Its nice to see faces to connect with these 3-digit names we have! When I met you, I commented on your USMC hat. The mini-conference on Spectroscopy inspired me enough to purchase a SA200 for my ST-10XME and successfuly got a nice calibrated image of Vega last night as well as a spectrum of NSV object which I nailed down the spectral type (MIII) using Rspec.
This was a great venue for me, 25 miles from my house, so I wounldn't mind meeting with AASVO there in the future.
The V1432 Aquilae campaign was a great read and makes me want to join CBA for a similar program. Hope everything was smooth on your way back to Phoenix!
James Foster, Los Angeles, CA
Hi Jim,
It was nice seeing you at SAS. I will be interested in hearing how the SA200 works out.
Regarding the USMC hat, I was active in the 1960's and like to promote the service.
Good luck with your observing.
Jeff
(HPO) 187283
To: Jeff,
Here is a calibrated spectra of Vega with a professional spectra of an A0V star in blue with the SA200 in my SBIG
CFW-9 filter wheel and ST-10XME: Here is one of NSV 9980 that matches a M1III spectra:
I'll post some picture I took at SAS later tonight.
James
Hi Jim,
Nice job. While wavelength calibration is good it is better see first profiles without normailztion or instrument correction or standard overlays. That's my choice.
I've attached a spectrum line profile taken with an SA100 and 8" LX90.
Jeff
187283
HPO
To: Jeff,
I'll post my non-normalized ones tonight.....great Vega spectrum!
James
To: Jeff,
Here you go on the link.....
http://www.astroimage.info/images/Vega-UncorrectedSpec2.jpg
James
Hi Jim,
Very nice profile. I hope you don't mind me offering some suggestions.
First, you do not need to include the psuedo spectrum at the bottom. All the interesting information is in the profile.
Second, experimnet with background and line color to give better contrast. Remember if the profie is printed out and the background is black, that uses a great amount of toner for the printer. A
nd lastly, While the profile looks good, I see your ADU counts (intensity) on the Y (vertical) axis are very low. They appear to be well under 1000 counts. See my profile where with just 0.25 second exposure the summed counts are a maximum of around 250,000 counts. What you should do is expeiment to see what the maximum pixel ADU count is for your camera and still be in the linear portion of counts vs. exposure time. Typically the linearity breaks around 45,000 ADU counts. Adjust the exposure so the star first order spectrum has a maximum count of that or less. Now when the coulmns are summend the count can get into the 100,000s. Remember also the zero spectrum count does not matter and may be saturdated at 65,000 counts.
Keep up the good work.
Jeff 187283
HPO
To: Jeff,
Thanks for the comments. I usually dont print anything as I usually look at these on a computer/tablet. My set-up is kinda unusal. I'm using a SBIG AO-L in-front of the filter wheel/ST-10 camera. The SA200 is screwed in "backwards" with respect to the other filters to maximize the distance between it and the sensor; it almost scrappes against the front plate of the CWF-9! My classical cassegrain is a 13.1" apeture working at F/7.4; no corrector plate or focal reducers.
My exposures ranged from 0.1 secs to 0.3 seconds. If I use any longer exposure, the Balmer lines near the blue-end completely merge/disappear even using planetary contrast in MaximDL. I made about 20 exposures (bin 1x1) and took the best 7 or so and summed them to get the most "contrasty" spectal lines. I don't think I'm getting artifact due to improper rotation; I only need to rotate in Rspec by 1.5 degrees to get a horizontal spectrum.
One thing I notice, the spectrum looks a little "tadpole-shaped" with the blunt end towards the source and a thinning towards the right. I made sure I'm on the "right-side" of the source since I can see the secondary, much dimmer spectrum on the left side of the source. Let me know if you have any other helpful advice. I'm a complete novice at spectroscopy, but have progressed steadily thanks to Rspec's great videos!.
James