Caroline's Rose Cluster (NGC 7789) - A Stunning Open Cluster in Cassiopeia

Basic Information

• Name: Caroline's Rose Cluster (NGC 7789)
• Other Names: The White Rose Cluster, Herschel's Spiral Cluster
• Type: Open Star Cluster
• Location: Constellation Cassiopeia
• Distance from Earth: Approximately 7,622 light-years.
• Apparent Magnitude: 6.7, making it visible with binoculars and small telescopes.
• Age: Estimated to be around 1.6 billion years old.

Discovery

• Caroline's Rose Cluster was discovered in 1783 by Caroline Herschel, a pioneering astronomer and comet-hunter.
• Her brother, William Herschel, later included it in his catalog as H VI.30.
• The cluster earned its nickname "Caroline's Rose" because its loops of stars and dark lanes resemble the petals of a rose when viewed visually.

Physical Characteristics

• Structure: The cluster is unusually rich and densely packed with stars, creating a striking visual pattern of loops and dark voids that resemble a rose.
• Star Composition: The cluster contains a mix of white and yellow stars, which form intricate patterns resembling the borders of rose petals.
• Size: The cluster spans about 50 light-years across.

Observational Highlights

• Best Time to View: Caroline's Rose Cluster is best observed during autumn and winter months in the Northern Hemisphere when the constellation Cassiopeia is high in the sky.
• Visibility: It is visible with binoculars or a small telescope under dark skies. Larger telescopes can reveal its intricate structure and individual stars.
• Nearby Objects: Located in the rich star fields of Cassiopeia, it is surrounded by other notable deep-sky objects, making it a great target for stargazing.

Interesting Facts

1. Cultural Significance: The cluster is named after Caroline Herschel, one of the first women to make significant contributions to astronomy.
2. Appearance: The dark lanes and loops of stars give the impression of a rose, making it one of the most visually striking open clusters.
3. Age and Evolution: At 1.6 billion years old, the cluster is relatively old for an open cluster, and many of its original stars have already evolved into red giants.

How to Locate Caroline's Rose Cluster

1. Find Cassiopeia: Locate the "W"-shaped constellation Cassiopeia in the northern sky.
2. Look Between Stars: The cluster is situated between the stars Ruchbah (Delta Cassiopeiae) and Beta Cassiopeiae.
3. Use Binoculars or a Telescope: Even binoculars can reveal the cluster's faint glow, while a telescope will show its intricate rose-like structure.

Personal Note

The 17 minutes 30 seconds exposure managed to bring some fainter stars in the cluster, but a few of the brighter ones became a bit too glazed. It was a bit challenging to capture the image since confirmed count is about 2,799 stars in a span of 50 light years that is visible in the cluster from earth. Using a glare reducing filter may have produced a better result here. The geometric pattern at the centre of the image roughly forms that of a rose, resulting to the cluster getting its name as such.