Here is a recently acquired spectrum of Be star HD93521taken with a CDK17 reflector at f/6.8 with the JTW L-200 spectroscope using the 1800 l/mm grating using the Atik 460ex for a 40 minute exposure; 8x300sec.'s 2x2 binned:
As previous, this was processed in IS and IR corrected against the Miles star HD101606 (F4V).
One thing that I don't understand, when processed with Isis, I get the value SPE_RPOW= 3685 / Spectral resolution power for my R, but when I compute R using the SimSpec_V4_1c_L200.wks speadsheet, my value is closer to 7400, which I used on this chart. It seems like IS is computing my R at half the value it should be.
James
Be Star HD93521
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Be Star HD93521
James Foster
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
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Re: Be Star HD93521
Hi James,
R~ 3700 is indeed unreasonably low for an L200/LHIRES and 1800 grating unless the slit is unusually wide or is out of focus. What is the resolution as measured in the neon lamp spectrum (FWHM of a line?) If the neon lamp is internal to the spectrograph this is normally a good approximation to the true resolution and is how ISIS calculates it.
Cheers
Robin
R~ 3700 is indeed unreasonably low for an L200/LHIRES and 1800 grating unless the slit is unusually wide or is out of focus. What is the resolution as measured in the neon lamp spectrum (FWHM of a line?) If the neon lamp is internal to the spectrograph this is normally a good approximation to the true resolution and is how ISIS calculates it.
Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
http://www.threehillsobservatory.co.uk
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Re: Be Star HD93521
To: Robin,
Thanks for the reply!
My slit is 34 microns. Here is a chart showing my Neon lines around Ha, Dispersion is 0.20784831A/px according to Bass 1.96:
Note that I did not use any 2nd or 3rd order averaging of the lines for this file, the is only a map I use when I process in Isis and use manual Ha.lst file I made for my line calibration. For curiosity here are the (RELCO) line calibration numbers for my Ha.lst file for Isis to process:
2
0.20784831
6416.3101 (Ar)
6506.5298 (Ne)
6532.8799 (Ne)
6598.9502 (Ne)
6678.2800 (Ne)
Funny thing is, when I bring in a IS processed spectrum into Bass V1.96, the typical Ha dispersion shown in the bottom info ribbon is 0.01039242 nm/px. Isn't this 1/2 the vale of the above? (0.1039 A/px vs 0.2078 A/px).
James
Thanks for the reply!
My slit is 34 microns. Here is a chart showing my Neon lines around Ha, Dispersion is 0.20784831A/px according to Bass 1.96:
Note that I did not use any 2nd or 3rd order averaging of the lines for this file, the is only a map I use when I process in Isis and use manual Ha.lst file I made for my line calibration. For curiosity here are the (RELCO) line calibration numbers for my Ha.lst file for Isis to process:
2
0.20784831
6416.3101 (Ar)
6506.5298 (Ne)
6532.8799 (Ne)
6598.9502 (Ne)
6678.2800 (Ne)
Funny thing is, when I bring in a IS processed spectrum into Bass V1.96, the typical Ha dispersion shown in the bottom info ribbon is 0.01039242 nm/px. Isn't this 1/2 the vale of the above? (0.1039 A/px vs 0.2078 A/px).
James
James Foster
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
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Re: Be Star HD93521
James,
You can use the "Measurement options" in BASS project to find the FWHM of one of the neon lines...it also calculates the R value based on that line. This should be used in preference to SimSpec.
You can use the "Measurement options" in BASS project to find the FWHM of one of the neon lines...it also calculates the R value based on that line. This should be used in preference to SimSpec.
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before....
"Imaging Sunlight - Using a digital Spectroheliograph" - Springer
http://www.astronomicalspectroscopy.com
"Imaging Sunlight - Using a digital Spectroheliograph" - Springer
http://www.astronomicalspectroscopy.com
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Re: Be Star HD93521
To: Ken,
Thanks! I'll check that out.
James
Thanks! I'll check that out.
James
James Foster
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200