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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 7:47  
clear_day Transit: 11:49  
SunsetSet: 15:50 south
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Other deep sky objects in Sagittarius
All Constellations »  Sagittarius »  Deep Sky Objects » 

IC 4991 - Lenticular Galaxy in Sagittarius

Altitude: -33.0°   Azimuth: 243.8°   Direction: West-South-West

IC 4991 is a Lenticular Galaxy in the Sagittarius constellation. IC 4991 is situated south of the celestial equator and, as such, it is more easily visible from the southern hemisphere.

IC 4991
Galaxy
Sagittarius

IC 4991 is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -33.0°
Azimuth: 243.8°
Direction: West-South-West

See also IC 4991 rise and set times.

Given its B magnitude of 12.33, IC 4991 is visible with the help of a telescope having an aperture of 8 inches (200mm) or more.

Available Resources for IC 4991 - Lenticular Galaxy in Sagittarius

Photometric information of IC 4991

The following table lists the magnitude of IC 4991 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).

12.33
9.45
8.8
8.49

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

The surface brightess reported below is an indication of the brightness per unit of angular area of IC 4991.

23.73 mag/arcsec2

Apparent size of IC 4991

The following table reports IC 4991 apparent angular size. The green area displayed on top of the DSS2 image of IC 4991 is a visual representation of it.
2.91 arcmin
2.13 arcmin
129°

Digitized Sky Survey image of IC 4991

The image below is a photograph of IC 4991 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 0.5x0.5 degrees (30x30 arcmins).

Image of IC 4991 - Lenticular Galaxy in Sagittarius star
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DSS2 image of IC 4991 in the Red band. The green region on the image is a representation of the major (2.91 arcmin) and minor (2.13 arcmin) axes of the object's apparent size.

IC 4991 - Lenticular Galaxy in Sagittarius morphological classification

IC 4991 - Lenticular Galaxy in Sagittarius is classified as Lenticular (S0) according to the Hubble and de Vaucouleurs galaxy morphological classification. The diagram below shows a visual representation of the position of IC 4991 - Lenticular Galaxy in Sagittarius in the Hubble de Vaucouleurs sequence.

IC 4991 - Lenticular Galaxy in Sagittarius
Visualization of the morphological classification of IC 4991 - Lenticular Galaxy in Sagittarius, Lenticular (S0).
Credits for the background image: Antonio Ciccolella / M. De Leo / CC BY

Celestial coordinates and finder chart of IC 4991

Celestial coordinates for the J2000 equinox of IC 4991 are provided in the following table:

20h 18m 23s
-41° 03’ 01”

The simplified sky charts below show the position of IC 4991 in the sky. The first chart has a field of view of 60° while the second one has a field of view of 10°.

Finder chart IC 4991 - Lenticular Galaxy in Sagittarius star
Simplified finder chart for IC 4991 - Lenticular Galaxy in Sagittarius.

Finder chart IC 4991 - Lenticular Galaxy in Sagittarius star
Simplified finder chart for IC 4991 - Lenticular Galaxy in Sagittarius.

Rise ans set times of IC 4991 from your location

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

IC 4991 - Lenticular Galaxy in Sagittarius is currently not visible from Greenwich, United Kingdom edit_location_alt