Cheltenham Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

19.26

Bortle class

Class 7 (Class 7)

Darkness Quotient

36%

Dataset

April 2026

Suburban/urban transition

Cheltenham: The Practical Verdict

Cheltenham, a small city in Gloucestershire, provides a suburban stargazing environment with high light pollution. The sky quality is classified as poor for astronomy, with limited visual deep-sky observation capabilities due to the strong urban glow.

From this location, only the brightest celestial targets are visible. The Moon and planets are your best options, alongside bright double stars and open clusters. Narrowband imaging remains feasible for certain bright nebulae, but broader deep-sky imaging or nuanced visual exploration is severely constrained.

For significantly better conditions, consider travelling west to Cradoc, around a two-hour drive away. Offering a much darker Bortle 4 sky, it provides access to the rich deep-sky views not possible within Cheltenham itself.

At a Glance

Overall

Poor urban/suburban sky - This is a poor sky for astronomy. The Moon, planets, and a few bright objects remain viable, but deep-sky work is difficult.

Milky Way

Not visible - The Milky Way is not realistically visible from this level of light pollution.

Best targets from here

Moon, planets, bright double stars, bright open clusters, narrowband imaging with careful processing

Do not prioritise

visual deep-sky observing, broadband galaxies, reflection nebulae, Milky Way photography

Best nearby upgrade

Cradoc sits about 93 km west and reaches Bortle 4, roughly 6.3x darker.

Moderate dark window

Cheltenham's limiting factor is not only light pollution. Around midsummer, Cheltenham loses true astronomical darkness entirely, so deep-sky observing and imaging are strongly seasonal. Plan serious sessions around the darker months.

Frequently Asked Questions

Can you see the Milky Way from Cheltenham?

No. Cheltenham is a Bortle Class 7 sky with SQM 19.26, so the Milky Way is not visible from the city. For Milky Way photography, look for a Bortle 4 or darker site.

What Bortle class is Cheltenham?

Cheltenham is Bortle Class 7 (SQM 19.26), a poor urban/suburban sky for astronomy.

Is Cheltenham good for stargazing?

Not for serious deep-sky observing. Cheltenham is a poor urban/suburban sky where the Moon, planets, and a handful of bright targets are the realistic options from the city itself.

Is Cheltenham good for astrophotography?

Broadband deep-sky imaging is heavily compromised from Cheltenham and a Bortle 4 or darker site is strongly recommended. Narrowband imaging of bright emission nebulae remains viable from Cheltenham with appropriate Ha or OIII filters.

What can you observe from Cheltenham?

Primary targets from Cheltenham include Moon, planets, bright double stars, bright open clusters, narrowband imaging with careful processing. Targets such as visual deep-sky observing, broadband galaxies, reflection nebulae are not realistic from this sky.

Where are darker skies near Cheltenham?

The closest meaningfully darker mapped site is Weston Subedge, about 27 km north east of Cheltenham, reaching Bortle 4.

When is the sky darkest in Cheltenham?

The sky over Cheltenham is darkest around January, December. Significant summer limitation: around 63 nights per year have no true astronomical darkness.

Is light pollution in Cheltenham getting better or worse?

Long-term light pollution over Cheltenham has been broadly stable across the available measurements.

• Weston Subedge

  Direction

  NE

  Distance (km)

  27.4

  SQM

  20.84

  Bortle

  4

• Dean

  Direction

  E

  Distance (km)

  39.7

  SQM

  20.82

  Bortle

  4

• Upton Snodsbury

  Direction

  SSW

  Distance (km)

  30.1

  SQM

  20.36

  Bortle

  5

• Upton Scudamore

  Direction

  S

  Distance (km)

  74.9

  SQM

  20.93

  Bortle

  4

• Cradoc

  Direction

  W

  Distance (km)

  93.4

  SQM

  21.25

  Bortle

  4

• Mainstone

  Direction

  NW

  Distance (km)

  96.4

  SQM

  21.17

  Bortle

  4