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public  Greenwich, UK Greenwich, UK  ⓘ
Timezone: Europe/London
Sunrise: 5:06 
Transit: 12:56 
Sunset: 20:47
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In Evidence

New Comet C/2025 J1 (Borisov) Discovered in May 2025
Detailed information about the discovery of Comet C/2025 J1 (Borisov) and pointers to useful resources to track and observe it. Read more...

Other deep sky objects in Mensa
All Constellations »  Mensa »  Deep Sky Objects » 

NGC 1791 - Open Cluster in Mensa

Below the horizon.  Never rises today
Alt: -34.66°   Az: 194.68°   Direction: South-South-West

NGC 1791 is a Open Cluster in the Mensa constellation. NGC 1791 is situated south of the celestial equator and, as such, it is more easily visible from the southern hemisphere. Given its visual magnitude of 13.12, NGC 1791 is visible with the help of a telescope having an aperture of 10 inches (250mm) or more.

The image below is a photograph of NGC 1791 from the Digitized Sky Survey 2 (DSS2 - see the credits section) taken in the red channel. The area of sky represented in the image is 0.5000x0.5000 degrees (30.00x30.00 arcmins).

Image of NGC 1791 - Open Cluster in Mensa star
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DSS2 image of NGC 1791 in the Red band. The green region on the image is a representation of the major (1.2 arcmin) and minor (1 arcmin) axes of the object's apparent size.

Celestial Coordinates

Apparent

04h 58m 53s
-70° 07’ 54”
02h 31m 18s
07h 30m 12s

J2000

04h 59m 06s
-70° 10’ 08”

Finder Chart

The simplified sky charts below show the position of NGC 1791 in the sky. The first chart has a field of view of 60° while the second one has a field of view of 10°.

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Finder chart for NGC 1791 - Open Cluster in Mensa.

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Finder chart for NGC 1791 - Open Cluster in Mensa.

Photometric Information

The following table lists the magnitude of NGC 1791 in different bands of the electomagnetic spectrum (when available), from the B band (445nm wavelength, corresponding to the Blue color), to the V band ( 551nm wavelength, corresponding to Green/Yellow color), to the J, H, K bands (corresponding to 1220nm, 1630nm, 2190nm wavelengths respectively, which are colors not visible to the human eye).

13.45
13.12

For more information about photometry in astronomy, check the photometric system article on Wikipedia.

Apparent Size

The following table reports NGC 1791 apparent angular size. The green area displayed on top of the DSS2 image of NGC 1791 is a visual representation of it.
1.2 arcmin
1 arcmin
30°

Rise and Set Times

Location: Greenwich, UK
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

NGC 1791 - Open Cluster in Mensa is currently not visible from Greenwich, UK