I don't think so so. Why should it be any better or worse than dry nitrogen or air. Any small effects (if any) should calibrate out.
Regards Andrew.
Search found 337 matches
- Thu Jul 11, 2019 1:11 pm
- Forum: Spectroscopes and Softwares
- Topic: Starlight Express Trius SX694 with The Lhires
- Replies: 2
- Views: 2784
- Wed Jun 26, 2019 3:03 pm
- Forum: UVEX Project
- Topic: UVEX Fibre interface
- Replies: 2
- Views: 3254
UVEX Fibre interface
I am interested in studying M Dwarf flare stars at very low resoultionand high cadance (20s exposures) At normal levels the stars are IR dominated and when flaring UV dominated so the UVEX seems ideal. However, it would suit me to use my Shelyak fibre guide head. Are there any studies of the UVEX wi...
- Thu May 09, 2019 10:23 am
- Forum: Spectroscopes and Softwares
- Topic: dual echelle/long slit high/low resolution spectrograph
- Replies: 2
- Views: 2462
Re: dual echelle/long slit high/low resolution spectrograph
At F20 with my seeing I doubt I could get much light into it!
Looks impressive though.
Regards Andrew
Looks impressive though.
Regards Andrew
- Mon Apr 22, 2019 9:26 am
- Forum: Spectra, results, information on activity ...
- Topic: Chromospheric active stars: a key program for amateurs
- Replies: 32
- Views: 427958
Re: Chromospheric active stars: a key program for amateurs
EW measurements are only resolution independent in the absence of blending. If a line is fully resolved at one resolution it will not have the same EW at aresolution where it is blended with one or more additional lines..
Regards Andrew
Regards Andrew
- Sat Apr 20, 2019 5:26 pm
- Forum: Spectroscopes and Softwares
- Topic: Master Calibration images
- Replies: 5
- Views: 3706
Re: Master Calibration images
Hi again Woody. On 5) yes dark subtraction adds randon noise which is why you need to combine many of them to minimise it. However, it removes systematic error (from the addition of the dark current to the signal) which can be important in calibration. Obviously, if it is low enough it could be miss...
- Sat Apr 20, 2019 5:19 pm
- Forum: Spectroscopes and Softwares
- Topic: Master Calibration images
- Replies: 5
- Views: 3706
Re: Master Calibration images
Hi Woody, I am not Christian but I can say how I approached 2). I took a dark frame and ran it through cosmetic file creation process with different thresholds. I then plotted the number of marked pixels v threshold. Then from this I judged where to make the cut. I had a sharp rise as the threshold ...
- Tue Apr 09, 2019 4:15 pm
- Forum: Spectroscopes and Softwares
- Topic: Are clouds really grey ?
- Replies: 6
- Views: 4859
Re: Are clouds really grey ?
Robin, according to the met office as the water droplets in cloud are much larger than the wavelength of visible light they scatter all visible wavelengths equally. Thus clouds are gray to first order.
Regards Andrew
Regards Andrew
- Sat Mar 30, 2019 8:00 am
- Forum: Spectra, results, information on activity ...
- Topic: CoMaC 2 spectrum
- Replies: 3
- Views: 5640
Re: CoMaC 2 spectrum
Congratulations a fine observation.
Regards Andrew
Regards Andrew
- Fri Mar 01, 2019 6:13 pm
- Forum: UVEX Project
- Topic: Présentation UVEX au SMSW2 2019
- Replies: 4
- Views: 3880
Re: Présentation UVEX au SMSW2 2019
Excellent presentation and development.
Regards Andrew
Regards Andrew
- Sun Jan 20, 2019 11:05 am
- Forum: Spectroscopes and Softwares
- Topic: Spectro en remote au Soleil !!
- Replies: 8
- Views: 5761
Re: Spectro en remote au Soleil !!
If people are serious in wanting to do this then I would certainly be interested if the site were in Europe. Indeed I would be happy to offer some of my kit. I could provide a OO CDK16 (400mm) on a Paramount ME II with The Sky X software. In addition I have attached an FLI Atlas focuser with Innovat...