some lo-res spectra

[nytecam]

Recent series of expanded stellar spectra of bright stars via RO200 grating in very brief exposures [fractions of second] and SN 2014J in 60s exp - data on image

[Merlin66]

Maurice,

I think some additional words of explanation are needed.....

Why three exposures?

What does the "Code" mean.....

[Gasman]

Maurice - Are they exposures over three separate nights or different exposures over a single night?

regards

Steve

[nytecam]

Hi Steve - all spectra taken in single exposures on Feb 18 and are slitless 'field' spectra.  Rather than my normal technique to 'average' the spectrum [typically 4-6 pixels 'high'] to a single pixel high then re-expand for display, I've simply vertically expanded the spectrum ~x30 and selected three sections that better show the extremes into violet and NIR.  The is some geometric distortion onto the CCD and atmospheric diffraction especially for lowly Rigel !  I use PaintShopPro to manipulate/montage images. Hope that clarifies.  

A decade ago I got Starlight Xpress to incorporate a "profile a single CCD row" into the camera control/processing s/ware and by carefully aligning the spectra horizontally prior to capture.  I've used this feature exclusively since.  No instrumental or atmospheric correction applied.    May upgrade to the French s/ware someday!

Note that binary Castor is resolved with slight offset of either spectra - both type A.

Here's a 30s field shot of M42 trapezium region

[nytecam]

Here's my Callisto spectrum eg reflected sunlight from Feb 18 too.  Other sats lost in Jupiter's glare for satisfactory results   

[Gasman]

Rather than my normal technique to 'average' the spectrum [typically 4-6 pixels 'high'] to a single pixel high then re-expand for display,

Hi Maurice

I used to do something similar with my Star Analyser - reduce the spectrum to a single pixel then expand it to 25 pixels but I don`t seem to need to do that using my Alpy slit spectroscope with Rspec as I just use its 10pixel background removal above and below the spectrum and it seems to work fine (maybe I should try reducing it to one pixel again for a cleaner spectrum??).

My only problem with the Alpy is getting the slit perfectly horizontal as try as I will I can only get it within 0.9 degs and I have to do a -0.9degs rotation for each spectrum I process!

regards

Steve

[Merlin66]

Steve,

You need to introduce Maurice to John's BASS Project.....