A dense old cluster, resolved into a spray of stars that thickens toward the center.
- What am I looking at?
- The Hercules Globular Cluster is a dense ball of hundreds of thousands of stars bound by gravity.
- How far away is it?
- About 22,200 light-years away.
- Where is it in the sky?
- In Hercules, between the bright stars Vega and Arcturus.
- Why does it matter?
- One of the finest globular clusters visible from the northern hemisphere.
- When is the best time to photograph it?
- Summer when Hercules is high in the evening sky.
Capture summary
Cluster in Hercules
Natural color
Broadband RGB
Summer target / square composition
- Optolong L-Pro 2h 24 x 300s
Same target, different years.
Older revisions stay in the archive so you can see how the target changed with different equipment, processing, and experience.
When to image this target
Cluster in Hercules; best planned for June through August from New Jersey.
Summer targets often improve later at night as the Milky Way climbs higher.
Assumes a New Jersey backyard horizon and evening imaging.
Stable seeing helps star color, roundness, and tight cluster detail.
M13 is listed here in Hercules.
Current frame: Natural color / Broadband RGB.
Live altitude, moon, and filter guidance
Calculating target altitude and moon context.
Use the full planner to enter a ZIP code, choose a date, and compare the target from your sky.
Based on the current time.
Green marks usable dark-sky altitude.
Next upper transit.
Approximate horizon crossing.
Moon phase and altitude.
Acquisition & processing notes
Filter channels, integration times, and capture dates for this frame.
- Optolong L-Pro 24 x 300s, 2h
How I captured this
| Channel | Frames | Time |
|---|---|---|
| Optolong L-Pro | 24 x 300s | 2h |
- Equipment used
- From my current rig
- Mount
- iOptron CEM60
- Telescope
- Explore Scientific FCD100 127mm Carbon Fiber Triplet APO
- Camera
- ZWO ASI2600MM Pro
- Filters
- Chroma 36mm Ha, OIII, SII, and LRGB (ZWO EFW 7×36mm)
- Focuser / rotator
- MoonLite NiteCrawler
- Reducer
- Starizona Apex ED 0.65×
- Guiding
- ZWO off-axis guider + ASI290MM Mini
- Control / power
- PrimaLuceLab Eagle 4S, Powerwerx PSU, Bioenno field battery, and MEGAbox
