NGC 7635 (Bubble Nebula) · ATR2600C · 2025-09-14

The Bubble Nebula, also known as NGC 7635, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in November 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉.

[Source: Wikipedia, en.wikipedia.org/wiki/Bubble_Nebula]

Annotated Image

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Sky Location

The chart above shows where this image sits on the night sky. The yellow outline is its field of view, with the picture itself drawn at its true orientation; north is up and east is left. Click the chart to zoom in, and use "open full resolution" for the full-size chart.

Image Details

AstroWizard Processing

1. GraXpert background extraction (0.5)
2. Color calibration
3. BlurXTerminator (0.6)
4. NoiseXTerminator (linear, 0.9) (x2)
5. NoiseXTerminator (linear, 0.6) (x2)
6. Stretch (custom)
7. Generalized Hyperbolic Stretch (x2)
8. Generalized Hyperbolic Stretch (starless)
9. Star removal (StarXTerminator)
10. Contrast (pop) adjustment
11. Darken background
12. Star recombination (screen blend)

The Bubble Nebula, also known as NGC 7635, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in November 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉.

[Source: Wikipedia, en.wikipedia.org/wiki/Bubble_Nebula]

Sky Location

The chart above shows where this image sits on the night sky. The yellow outline is its field of view, with the picture itself drawn at its true orientation; north is up and east is left. Click the chart to zoom in, and use "open full resolution" for the full-size chart.

Image Details

AstroWizard Processing

1. Crop
2. GraXpert background extraction (0.5)
3. Color calibration
4. BlurXTerminator (0.6)
5. NoiseXTerminator (linear, 0.9) (x2)
6. Generalized Hyperbolic Stretch (x6)
7. Stretch (deep)
8. Generalized Hyperbolic Stretch (starless)
9. Star removal (StarXTerminator)
10. Color recalibration
11. Darken background (x2)
12. Contrast (pop) adjustment
13. Curves adjustment
14. SCNR (green noise removal)
15. NoiseXTerminator (non-linear, 0.6)
16. Star recombination (screen blend)
17. Stretch (aggressive)

The Bubble Nebula, also known as NGC 7635, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in November 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉.

[Source: Wikipedia, en.wikipedia.org/wiki/Bubble_Nebula]

Sky Location

The chart above shows where this image sits on the night sky. The yellow outline is its field of view, with the picture itself drawn at its true orientation; north is up and east is left. Click the chart to zoom in, and use "open full resolution" for the full-size chart.

Image Details

PixInsight Processing

1. Image Integration (x3)
2. Channel Combination
3. PixelMath
4. Dynamic Crop

The Bubble Nebula, also known as NGC 7635, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in November 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉.

[Source: Wikipedia, en.wikipedia.org/wiki/Bubble_Nebula]

Sky Location

The chart above shows where this image sits on the night sky. The yellow outline is its field of view, with the picture itself drawn at its true orientation; north is up and east is left. Click the chart to zoom in, and use "open full resolution" for the full-size chart.

Image Details

PixInsight Processing

1. Image Integration (x3)
2. Channel Combination
3. PixelMath
4. Dynamic Crop

The Bubble Nebula, also known as NGC 7635, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in November 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉.

[Source: Wikipedia, en.wikipedia.org/wiki/Bubble_Nebula]

Sky Location

The chart above shows where this image sits on the night sky. The yellow outline is its field of view, with the picture itself drawn at its true orientation; north is up and east is left. Click the chart to zoom in, and use "open full resolution" for the full-size chart.

Image Details

PixInsight Processing

1. Image Integration (x3)
2. Channel Combination
3. PixelMath
4. Dynamic Crop

The Bubble Nebula, also known as NGC 7635, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in November 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉.

[Source: Wikipedia, en.wikipedia.org/wiki/Bubble_Nebula]

Sky Location

The chart above shows where this image sits on the night sky. The yellow outline is its field of view, with the picture itself drawn at its true orientation; north is up and east is left. Click the chart to zoom in, and use "open full resolution" for the full-size chart.

Image Details

PixInsight Processing

1. Image Integration (x3)
2. Channel Combination
3. PixelMath
4. Dynamic Crop