SH2-73 - Integrated Flux Nebula

Show astrometry data

Sharpless 73 (also known as LBN 105), in the constellation Hercules, was mistakenly added to the Sharpless catalog as an emission nebula. It was later realized that because there is no nearby hot star to ionize the gas, it is merely a molecular cloud in space outside the main disk of our Milky Way Galaxy. Lit by the integrated light from the galaxy, it is classified as an integrated flux nebula.

Integrated flux nebulae are very faint, in fact there is no listing for the surface brightness of this object. Picking the nebula out of sky noise (especially light pollution at our site one hour west of Bangkok) is especially difficult, and was only possible by taking a huge number of exposures using our wide field 300mm telescope array. The nebula was visible for about 3-1/2 hours each of the eight nights we shot. 465 Luminance, 174 Red, 172 Green and 173 Blue subexposures were taken using one FLI ML29052 and two FLI PL16803 CCD cameras cooled to -25C. More than 70 hours of data was collected. The image was processed in PixInsight and Photoshop.

Shot and processed by the SC Observatory Team: Mike Selby, Stefan Schmidt and Andy Chatman

Object details

Integrated Flux Nebula in Hercules

Right Ascension: 16h 07m 59s

Declination: 21º 52' 00''

Magnitude: N/A

Moon Age Average: 14.82 days

Moon Phase Average: 15.18 %

Imaging Setup

Location:

SC Observatory, Central Thailand

Date:
Apr 11, 2018, Apr 12, 2018, Apr 13, 2018, Apr 14, 2018, Apr 18, 2018, Apr 19, 2018, Apr 20, 2018 and Apr 21, 2018
Telescope:
Officina Stellare Veloce RH 300
Focal Length:
900 mm
F-Ratio:
F/3
Mount:
Officina Stellare Polar Fork
Camera:
FLI ML 29052
Image Scale:
1.26 arcseconds/pixel
Imaging Software:

Voyager

Processing Software:

Adobe Photoshop

PixInsight 1.8


Exposure Detail

Filter Filter Brand Bin Qty Exposure
L Astrodon 1x 96 300
L Astrodon 1x 33 480
L Astrodon 1x 17 600
R Astrodon 2x 174 150


Imaging Setup

Location:

SC Observatory, Central Thailand

Date:
Apr 11, 2018, Apr 12, 2018, Apr 13, 2018, Apr 14, 2018, Apr 18, 2018, Apr 19, 2018, Apr 20, 2018 and Apr 21, 2018
Telescope:
Officina Stellare Veloce RH 300
Focal Length:
900 mm
F-Ratio:
F/3
Mount:
Officina Stellare Polar Fork
Camera:
FLI PL 16803
Image Scale:
2.06 arcseconds/pixel
Imaging Software:

Voyager

Processing Software:

Adobe Photoshop

PixInsight 1.8


Exposure Detail

Filter Filter Brand Bin Qty Exposure
L Baader 1x 109 300
L Baader 1x 39 480
L Baader 1x 23 600
G Baader 2x 172 150


Imaging Setup

Location:

SC Observatory, Central Thailand

Date:
Apr 11, 2018, Apr 12, 2018, Apr 13, 2018, Apr 14, 2018, Apr 18, 2018, Apr 19, 2018, Apr 20, 2018 and Apr 21, 2018
Telescope:
Officina Stellare Veloce RH 300
Focal Length:
900 mm
F-Ratio:
F/3
Mount:
Officina Stellare Polar Fork
Camera:
FLI PL 16803
Image Scale:
2.06 arcseconds/pixel
Imaging Software:

Voyager

Processing Software:

Adobe Photoshop

PixInsight 1.8


Exposure Detail

Filter Filter Brand Bin Qty Exposure
L FLI Chroma 1x 99 300
L FLI Chroma 1x 33 480
L FLI Chroma 1x 17 600
B FLI Chroma 2x 173 150


Total Exposure Time

70 hours, 27 minutes

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