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Sh2-274 (Gem), Medusa-Nebel
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| Date/Site: |
11., 12., 13. and 14. April 2023. Remote observatory on the AAR club's site in Presberg |
Exposure/
Filter: |
RGB: 40 x 120 seconds (-10°C),
L: 12 x 300 seconds
O3: 12 x 300 seconds
Hα: 6 x 300 seconds (-20°C) |
Camera/
Optics/
Instrument: |
Touptek 294CP on 150mm f/5 Newton with 2" Skywatcher Comacorrector,
Moravian G3-16200 with VIP-3010 Paracorr on 10Micron GM1000 HPS |
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Data acquired remotely with N.I.N.A.,
Guiding: ASI120 attached to a 61mm-finder,
Focusing with Microtouch,
Calibration and processing: MaximDL 6 and PixInsight 1.8 |
Planetary nebula Sh2-274, also called Abell 21 or Medusa-Nebula, seems to be compressed in one direction, in the other one the gaseous glow looks ragged.
There were setbacks during the change to N.I.N.A. After some initial successes it didn't work very well; observing was demanding: sometimes the telescopes were not aligned correctly, and then I made wrong decisions in N.I.N.A.
Probably have to put it under learning.
Nevertheless I rate this image as better as the results from earlier years.
2019 and 2020 I tried this object already:
Sh2-274 (Gem), Medusa-Nebula
Click on the image for a larger version
| Date/Site: |
26. and 28. February 2019, 25., 28. March and 23. April 2020. Remote observatory on the AAR club's site in Presberg |
Exposure/
Filters: |
R: 16 x 180 seconds,
G: 12 x 180 seconds,
B: 12 x 180 seconds,
Hα: 8 x 600 and 13 x 300 seconds,
O3: 6 x 600 and 22 x 300 seconds, (-20°C) |
| Camera: |
QSI 632 with Astronomik Type II-filters |
Optics/
Instrument: |
250mm f/4 Newton with Baader RCC1 on 10Micron GM1000 HPS |
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Guiding: Lodestar attached to a 61mm-finder,
focusing: Microtouch and FocusMax,
data acquired remotely using CCD-Commander and MaximDL 6,
calibration and processing: PixInsight 1.8 |
Following the modified bicolor technique by Cannistra and Wechselberger by combining Hα- and OIII-frames for a synthetic green channel a pseudo-RGB-colour version was created.
The RGB-image is nice too:
Medusa-Nebel, Sh2-274 (Gem) in RGB
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And here NB-data were added to the RGB-image.
Medusa-Nebel, Sh2-274 (Gem), RGB, Hα and O3
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It's tempting to make increasingly longer exposures to catch the enormous expanse of the nebulae in Hα- and O3.
The Medusa-nebula aka PLN205+14.1 or Abell 21 in an earlier version with the club's refractor:
Sh2-274 (Gem), Medusa-Nebel
Click on the image for a larger version
| Date/Site: |
January 16th, 2012, AAR-observatory in Presberg |
Exposure/
Filter: |
Hα (Baader 7nm): 6 x 600 seconds,
R: 4 x 600 seconds, G: 2 x 600 seconds, B: 2 x 600 seconds (-15°C) |
| Camera: |
SBIG ST10XME, CFW9 with SBIG LRGB-filters |
Optics/
Instrument: |
4“-TMB on Gemini 41 Field |
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Calibration: MaximDL 5,
processing: PixInsight 1.7 and Photoshop |
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