The Flickr Ngc2367 Image Generatr

Gum Nebula was visible clearer in HII OIII starless version below:
www.flickr.com/photos/hiroc/53822710308

We can not see the big red nebula. It is too faint for our unaided eyes to feel directly, but we can feel the existence of Gum Nebula as a vast G-shaped dark part in the sky as below. It spans about 40 degrees. www.flickr.com/photos/hiroc/16311565540

Gum Nebula exists about 1kLY away from us, and the diameter is about 1kLY. It means that Gum Nebula is extremely large and incredibly close to us, almost reaching us by the half way. Gum Nebula is believed to be old supernova remnant, which exploded about 1 million years ago. It means that the gas shell will reach us 1 million years after today, if we can assume that the expanding velocity is constant.

arctan 1/2 = 26.6 degrees, and angular diameter is 2 x 26.6 = 53 degrees, about 40 degrees in digits. The diameter looks to be equivalent to the calculated angle including the faintest parts.

Colin Gum reported the vast hydrogen-alpha region first in 1955. His sketch (1956) is visible here:

"Colin Gum and The Discovery of The Gum Nebula" by Kerr FJ 1971:
ntrs.nasa.gov/citations/19720004102
ntrs.nasa.gov/api/citations/19720004102/downloads/1972000...

Equipment: Sigma 35mmF1.4 DG HSM Art, IDAS NB12 Dual Narrow Band Filter or Clear Filter, and EOS R6-SP5, modified by Seo San on ZWO AM5 Equatorial Mount, autoguided with Fujinon 1:2.8/75mm C-Mount Lens, Pentax x2 Extender, ZWO ASI 120MM-mini, and PHD2 Guiding

Exposure: 14 times x 60 seconds, 7 x 240 sec, and 8 times x 1,800 seconds at ISO 6,400 and f/3.2 with NB12 filter
6 times x 60 seconds, 6 x 240 sec, and 7 times x 900 seconds at ISO 1,600 and f/3.2 with clear filter

site: 2,430m above sea level at lat. 24 38 55 South and long. 70 16 52 West near Cerro Armazones Chile
SQML was 21.55 at the night. Ambient temperature was around 6 degrees Celsius or 43 degrees Fahrenheit.

Gum Nebula was visible clearer in HII OIII starless version below:
www.flickr.com/photos/hiroc/53822710308

Equipment: Sigma 35mmF1.4 DG HSM Art, IDAS NB12 Dual Narrow Band Filter or Clear Filter, and EOS R6-SP5, modified by Seo San on ZWO AM5 Equatorial Mount, autoguided with Fujinon 1:2.8/75mm C-Mount Lens, Pentax x2 Extender, ZWO ASI 120MM-mini, and PHD2 Guiding

Exposure: 14 times x 60 seconds, 7 x 240 sec, and 8 times x 1,800 seconds at ISO 6,400 and f/3.2 with NB12 filter
6 times x 60 seconds, 6 x 240 sec, and 7 times x 900 seconds at ISO 1,600 and f/3.2 with clear filter

site: 2,430m above sea level at lat. 24 38 55 South and long. 70 16 52 West near Cerro Armazones Chile
SQML was 21.55 at the night. Ambient temperature was around 6 degrees Celsius or 43 degrees Fahrenheit.

Equipment: Sigma 35mmF1.4 DG HSM Art, Clear Filter, and EOS R6-SP5, modified by Seo San on ZWO AM5 Equatorial Mount, autoguided with Fujinon 1:2.8/75mm C-Mount Lens, Pentax x2 Extender, ZWO ASI 120MM-mini, and PHD2 Guiding

Exposure: 6 times x 60 seconds, 6 x 240 sec, and 7 times x 900 seconds at ISO 1,600 and f/3.2

site: 2,430m above sea level at lat. 24 38 55 South and long. 70 16 52 West near Cerro Armazones Chile
SQML was 21.55 at the night. Ambient temperature was around 6 degrees Celsius or 43 degrees Fahrenheit.

Equipment: Sigma 35mmF1.4 DG HSM Art, Clear Filter, and EOS R6-SP5, modified by Seo San on ZWO AM5 Equatorial Mount, autoguided with Fujinon 1:2.8/75mm C-Mount Lens, Pentax x2 Extender, ZWO ASI 120MM-mini, and PHD2 Guiding

Exposure: 6 times x 60 seconds, 6 x 240 sec, and 7 times x 900 seconds at ISO 1,600 and f/3.2

site: 2,430m above sea level at lat. 24 38 55 South and long. 70 16 52 West near Cerro Armazones Chile
SQML was 21.55 at the night. Ambient temperature was around 6 degrees Celsius or 43 degrees Fahrenheit.

It was too late to take this object in May. The object was too low in the west, and a part of the frame got stars drifted due to differential atmospheric refraction. Atmospheric layer elevated stars near the horizon. North is up, and east is to the left.

We can not see the big red nebula. It is too faint for our unaided eyes. We can feel the existence of Gum Nebula as a vast G-shaped dark part in the sky as below. It spans about 40 degrees.
www.flickr.com/photos/hiroc/16311565540

Colin Gum reported the vast hydrogen-alpha region first in 1955. His sketch (1956) is visible here:

"Colin Gum and The Discovery of The Gum Nebula" by Kerr FJ 1971:
ntrs.nasa.gov/citations/19720004102
ntrs.nasa.gov/api/citations/19720004102/downloads/1972000...

We can not see Gum Nebula on "Atlas Coeli Skalnaté Pleso 1950.0" by Antonín Bečvář or on "Sky Atlas 2000.0" by Wil Tirion and Roger Sinnott, though Vela Supernova Remnant is on "Sky Atlas 2000.0." I have both big atlases. They are beautiful.

Equipment: Sigma 35mmF1.4 DG HSM Art, IDAS NB12 Dual Narrow Band Filter, and EOS R6-SP5, modified by Seo San on ZWO AM5 Equatorial Mount, autoguided with Fujinon 1:2.8/75mm C-Mount Lens, Pentax x2 Extender, ZWO ASI 120MM-mini, and PHD2 Guiding

Exposure: 14 times x 60 seconds, 7 x 240 sec, and 8 times x 1,800 seconds at ISO 6,400 and f/3.2

site: 2,430m above sea level at lat. 24 38 55 South and long. 70 16 52 West near Cerro Armazones Chile
SQML was 21.55 at the night. Ambient temperature was around 6 degrees Celsius or 43 degrees Fahrenheit.

It was too late to take this object in May. The object was too low in the west, and a part of the frame got stars drifted due to differential atmospheric refraction. Atmospheric layer elevated stars near the horizon. North is up, and east is to the left.

We can not see the big red nebula. It is too faint for our unaided eyes. We can feel the existence of Gum Nebula as a vast G-shaped dark part in the sky as below. It spans about 40 degrees.
www.flickr.com/photos/hiroc/16311565540

Colin Gum reported the vast hydrogen-alpha region first in 1955. His sketch (1956) is visible here:

"Colin Gum and The Discovery of The Gum Nebula" by Kerr FJ 1971:
ntrs.nasa.gov/citations/19720004102
ntrs.nasa.gov/api/citations/19720004102/downloads/1972000...

We can not see Gum Nebula on "Atlas Coeli Skalnaté Pleso 1950.0" by Antonín Bečvář or on "Sky Atlas 2000.0" by Wil Tirion and Roger Sinnott, though Vela Supernova Remnant is on "Sky Atlas 2000.0." I have both big atlases. They are beautiful.

Equipment: Sigma 35mmF1.4 DG HSM Art, IDAS NB12 Dual Narrow Band Filter, and EOS R6-SP5, modified by Seo San on ZWO AM5 Equatorial Mount, autoguided with Fujinon 1:2.8/75mm C-Mount Lens, Pentax x2 Extender, ZWO ASI 120MM-mini, and PHD2 Guiding

Exposure: 14 times x 60 seconds, 7 x 240 sec, and 8 times x 1,800 seconds at ISO 6,400 and f/3.2

site: 2,430m above sea level at lat. 24 38 55 South and long. 70 16 52 West near Cerro Armazones Chile
SQML was 21.55 at the night. Ambient temperature was around 6 degrees Celsius or 43 degrees Fahrenheit.

Edited European Southern Observatory image of the open star cluster NGC 2637.

Original caption: This rich view of an array of colourful stars and gas was captured by the Wide Field Imager (WFI) camera, on the MPG/ESO 2.2-metre telescope at ESOâs La Silla Observatory in Chile. It shows a young open cluster of stars known as NGC 2367, an infant stellar grouping that lies at the centre of an immense and ancient structure on the margins of the Milky Way.

Edited European Southern Observatory image of a wide-field view of the open star cluster NGC 2637.

Original caption: This wide-field view of the sky around the cluster NGC 2367 was created from photographic material forming part of the Digitized Sky Survey 2. The cluster itself is the tight knot of blue stars at the centre of the picture.

This rich view of an array of colourful stars and gas was captured by the Wide Field Imager (WFI) camera, on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. It shows a young open cluster of stars known as NGC 2367, an infant stellar grouping that lies at the centre of an immense and ancient structure on the margins of the Milky Way.

More information: www.eso.org/public/images/eso1526a/

Credit:
ESO/G. Beccari