NGC 7789 is an open star cluster in the constellation of Cassiopeia. It’s also known as Caroline’s Rose or the White Rose Cluster. It’s best viewed on autumn nights. With a rather bright magnitude of 6.7, it’s hard to believe Charles Messier didn’t catalog this large and dense cluster. Thankfully, in 1783, Caroline Herschel recorded this splendid object.
Astronomers often refer to NGC 7789 as a rose because the brighter stars and dark dust lanes resemble the circles and loops on the face of a blooming rose. At an age of over 1 billion years, this is an older open cluster, and it’s fairly distant from us at 8,000 light-years. Its diameter is estimated to be 60 light-years.
My Observations
| Date | November 17, 2022 |
| Time | 8:45 p.m. |
| Location | Seattle, WA |
| Magnification | 85x |
| Scope | Meade 8″ SCT |
| Eyepiece | 24mm |
| Seeing | Above Average |
| Transparency | Above Average |
| Date | November 15, 2022 |
| Time | 8: 50 p.m. |
| Location | Seattle, WA |
| Magnification | 127x |
| Scope | Meade 8″ SCT |
| Eyepiece | 16mm |
| Seeing | Average |
| Transparency | Average |
On November 15th, it took me a few moments to realize I was looking at Caroline’s Rose. After struggling to see any type of pattern among the dimmer stars on this cold, humid night, I noticed I was drawing with the variable eyepiece set to 16mm. My fingers were freezing, and I had had enough of the frigid temperatures and hazy skies, so I was hurrying to sketch the cluster to end so I could pack up the scope for the night.
Later that evening, from my office, I read through other descriptions of NGC 7789. I learned that I needed a wider view, as the cluster spans across the sky more than I originally studied. So I returned on November 17th to sketch the cluster with the 24mm eyepiece. While I couldn’t see the dark dust lanes due to light pollution, I was able to make out a “sea” of 11th and 12th-magnitude stars floating in the heavens. Thanks to Caroline and all her wonderful discoveries more than 200 years ago.
Key Stats
| Constellation | Cassiopeia |
| Best Viewing | Autumn |
| Visual Magnitude | +6.7 |
| Absolute Magnitude | -4.6 |
| Distance from Earth | 8,000 ly |
| Diameter | 60 ly |
| Apparent Size | 25 arcmin |
| Milky Way Location | Between Perseus/Orion Arm |
| My Viewing Grade | B |
Sources
Banner made with a photo of 7789 by Hewholooks. Info here. It is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Sketch by Wayne McGraw
AKA: NGC 7789, Caroline’s Rose, White Rose Cluster
The Garden Astronomer 
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