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NGC 6638

Set a site to see tonight's sky

When NGC 6638 is up, how long it stays usable and when it is in season all depend on where you observe from. Set your site and this page adds tonight's answer and its year.

Set it on Tonight

The science

What you are looking at

In one sentence

A dense, gravitationally bound swarm of very old stars orbiting in a galaxy's halo.

Class explainer for globular cluster (SIMBAD classification).

The facts

NGC 6638 is a globular cluster in Sagittarius. SIMBAD gives no distance for it, so its true size and light-travel time can't be worked out here. SIMBAD measures it at 3.0′ × 3.0′ on the sky — 10% of the full Moon's width. Framing uses its catalogue size instead: 4.2′. It shines at magnitude 9.7.

Sources: AstroBrain catalogue; CDS/SIMBAD astronomical database, Strasbourg (SIMBAD record NGC 6638). Contains information from SIMBAD, which is made available here under the Open Database License (ODbL). Download the SIMBAD-derived data.

For scale

Angular size, as it would sit on your sky.

The same patch of sky in visible light

Sky image
Observatory photos and open-licence sky surveys.
Credits on each image.

Neighbours in the sky

Sky maths: apparent positions with refraction, one-minute steps; usable = full astronomical dark, at least 30° up and clear of your skyline. Survey images: CDS, Strasbourg (DSS2 and other surveys). Science: SIMBAD. The hours, heights and Moon on this page use no weather forecast; the rank is this target’s place in the Targets list, whose score also counts the cloud forecast when there is one.

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NGC 6638

Set a site to see tonight's sky

When NGC 6638 is up, how long it stays usable and when it is in season all depend on where you observe from. Set your site and this page adds tonight's answer and its year.

Set it on Tonight

The science

What you are looking at

In one sentence

A dense, gravitationally bound swarm of very old stars orbiting in a galaxy's halo.

Class explainer for globular cluster (SIMBAD classification).

The facts

NGC 6638 is a globular cluster in Sagittarius. SIMBAD gives no distance for it, so its true size and light-travel time can't be worked out here. SIMBAD measures it at 3.0′ × 3.0′ on the sky — 10% of the full Moon's width. Framing uses its catalogue size instead: 4.2′. It shines at magnitude 9.7.

Sources: AstroBrain catalogue; CDS/SIMBAD astronomical database, Strasbourg (SIMBAD record NGC 6638). Contains information from SIMBAD, which is made available here under the Open Database License (ODbL). Download the SIMBAD-derived data.

For scale

Angular size, as it would sit on your sky.

The same patch of sky in visible light

Sky image
Observatory photos and open-licence sky surveys.
Credits on each image.

Neighbours in the sky

Sky maths: apparent positions with refraction, one-minute steps; usable = full astronomical dark, at least 30° up and clear of your skyline. Survey images: CDS, Strasbourg (DSS2 and other surveys). Science: SIMBAD. The hours, heights and Moon on this page use no weather forecast; the rank is this target’s place in the Targets list, whose score also counts the cloud forecast when there is one.

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