M57 - The Ring Nebula
From the author of Welcome to the Universe in 3D
Spectral images...
20:37-21:12 EDT October 10, 2022.
ZWO ASI2400MC-Pro camera and
RSpec Star Analyser 200 diffraction grating
on 10" RC at f/9.
35 min (unguided 30 second subexposures).
Image is cropped to highlight the Ring Nebula.
Click here to see the uncropped much larger field of view image.
North is down.
Each star appears as an undiffracted spot. Off to the right of each star spot is the order \( m=+1 \) diffracted spectral "streak". Associated with some of the brightest stars, it is also possible to see the order \( m=-1 \) diffracted spectrum off to the left of the star.
The undiffracted (\( m=0 \)) Ring Nebula appears as the nice colorful nebula just to the left of the center of the image. The blue and red rings off to the right are the \( m=+1 \) order diffractions of the nebula. The blue corresponds to O-III emissions from the nebula and the red corresponds to H-alpha emissions.
22:05-23:10 EDT August 5, 2021.
Canon T2i
DSLR and
RSpec Star Analyser 100 diffraction grating
on 10" RC at f/9.
60 min (unguided 60 second subexposures).
North is to the right.
If your screen is set fairly bright, you might also be able to see the \( m=+2 \) and \( m=-1 \) order diffractions of the Ring Nebula.
This picture is on display at Princeton's Art of Science Exhibition
This is the version that appeared in APOD
(it's not as good as the one above because of the smoke-filled skies from the fires out west)...
22:19-23:55 EDT July 15, 2021.
Canon T2i DSLR on 10" RC at f/9.
RSpec Star Analyser 100 diffraction grating,
87 min (unguided 60 second subexposures).
The \( m=+1 \) order diffractions appear to the left, not to the right.
21:53-23:29 EDT June 30, 2021.
Starlight Express Trius SX-694 on 10" RC at f/9.
Hα =43min, OIII=43min,
(unguided 20 second subexposures).
Richardson-Lucy deconvolution, gamma stretch.
21:44-22:35 EDT July 26, 2016 and 21:41-23:57 EDT July 27, 2016.
Starlight Express Trius SX-694 on 10" RC at f/9.
Hα =110min, OIII=50min,
(guided 10 minute subexposures).
Richardson-Lucy deconvolution.
Here's the Hα frames highly stretched to show the
surrounding faint nebulosity (and IC1296)
Here's an animated gif of the Hα frames as the stretching is changed
21:51 EDT August 16, 2018.
Starlight Express Trius SX-H694 on 10" RC at f/9.
RSpec Star Analyser 100 diffraction grating,
(44 unguided 30-second subexposures).
The sharp central ring is the undiffracted (m=0) image.
The three overlapping rings above the central ring are Ne-III (386nm), O-III (504nm), and Hα (656nm)
Click on image for 3-times higher resolution image.
22:15 EDT June 26, 2008.
Starlight Express SXV-H9 on 10" RC at f/9.
Hα=140min, OIII=20min,
(guided 20 minute subexposures).
PLUS: all prior exposures.
Richardson-Lucy.
Brighter version
02:16 EDT May 23, 2007.
Starlight Express SXV-H9 on 10" RC at f/9.
L=32.5min, Hα =30min, OIII=30min,
R=15min, G=15min, B=15min (guided 2.5 and 5 minute subexposures).
Richardson-Lucy, Custom Digital Development.
02:43 EDT May 5, 2005.
Starlight Express SXV-H9 on 10" RC at f/9.
L=13min, Hα =22min,
R=8min, G=8min, B=8min (unguided 1-minute subexposures).
Richardson-Lucy, Curves.
NOTE: the faintest stars in this image are at least mag 20.
23:07 EDT Aug 10, 2005.
Starlight Express SXV-H9 on 10" RC at f/9.
Hα =122min (unguided 30-second subexposures).
Richardson-Lucy, Gamma stretch.