NGC 2261 - Hubble's Variable Nebula

Introduction | Map | My Own Photos | My Own Observations | References

On this page I collect my observations of the galactic reflection nebula NGC 2261, called Hubble's Variable Nebula, in the constellation Monoceros/Unicorn.

Introduction

The galactic reflection nebula NGC 2261 in the constellation Monoceros / Unicorn, is called Hubble's Variable Nebula because it changes in detail. But this is only visible in large telescopes. The special thing about this nebula is its shape, which resembles a comet. The nebula is illuminated by the star R Monocerotis (R Mon), which is not directly visible itself.

In a Vespera mosaic, NGC 2261 can be observed together with NGC 2264/Cone Nebula. Actually, a small Vespera mosaic was the only possibility for me to find the Cone Nebula.

Size: 3' x 2' (Wikipedia)
Distance: 2,600 light years (Wikipedia)
Ranking: ** (Stoyan)

Map

NGC 2261, called Hubble's Variable Nebula, in the constellation Monoceros/Unicorn (Image Courtesy of SkySafari Astronomy, www.simulationcurriculum.com)

NGC 2261, called Hubble's Variable Nebula, in the constellation Monoceros/Unicorn, detail (Image Courtesy of SkySafari Astronomy, www.simulationcurriculum.com)

My Own Photos

eVscope


NGC 2261 - Feb 16, 2020, processed	NGC 2261 - Feb 16, 2020, processed	NGC 2261 - Feb 16, 2020, processed

NGC 2261 - Mar 8, 2021	NGC 2261 - Mar 8, 2021	NGC 2261 - Mar 8, 2021

NGC 2261 - Mar 8, 2021, processed	NGC 2261 - Mar 8, 2021, processed	NGC 2261 - Mar 8, 2021, processed

Vespera


NGC 2261 (top right) with NGC 2264 (left), Mar 28, 2024 - original, 2250s, small mosaic, Dual Band Filter		NGC 2261 (top right) with NGC 2264 (left), Mar 28, 2024 - large, 2250s, small mosaic, Dual Band Filter, photo left processed (PSE)

Ditto, photo additionally processed (DN) - large		Ditto, photo additionally processed (DN+PSE) - large

NGC 2261 (top right) with NGC 2264 (left), Apr 11, 2024 - original, 4570s, small mosaic, Dual Band Filter		NGC 2261 (top right) with NGC 2264 (left), Apr 11, 2024 - large, photo left processed (PSE)

Ditto, photo additionally processed (DN) - large		Ditto, photo additionally processed (DN+PSE), poor quality - large

My Own Observations

Observations February 2020

February 16, 2020 (Mühlhausen/Kraichgau: eVscope): NGC 2261 photographed

Observations March 2021

March 7, 2021 (Mühlhausen/Kraichgau: eVscope): NGC 2261 photographed in the rectangular format without overlay, eVscope defocused, photos discarded
March 8, 2021 (Mühlhausen/Kraichgau: eVscope): NGC 2261 photographed (r.f., n.o.), manually exposed

Observations March/April 2024

March 28, 2024 (Mühlhausen/Kraichgau: Vespera): NGC 2261 photographed (with NGC 2264), small mosaic, Dual Band Filter
April 11, 2024 (Mühlhausen/Kraichgau: Vespera): NGC 2261 photographed (with NGC 2264), small mosaic, Dual Band Filter, poor quality (sky fuzzy)

References

NGC 2261 (Wikipedia): en.wikipedia.org/wiki/NGC_2261
NGC 2264 (Wikipedia): en.wikipedia.org/wiki/NGC_2264