Your guide to the Solar System and the night sky
✖ By donating now you help keep this site alive and free from ads. Please consider supporting this project.
🌎  Observing from: Greenwich, United Kingdom [change]
🌅 Sunrise: 6:41  ☀️ Transit: 13:03  🌅 Sunset: 19:26

How to support us

You won't see any ads here. If you find this website useful, please consider a donation to help cover the costs of the infrastructure needed to run this website. Thank you!

In Evidence

Best Places to See the 2024 American Eclipse Based on Historical Weather Data
Using historical cloud coverage data we suggest the locations that could provide the better chances to have clear skies on April 8, 2024 to observe the eclipse. Read more...
February 17, 2023
Where to See the Solar Eclipse of April 20 2023
Detailed information about how to observe the hybrid solar eclipse that will be visible on April 20 2023. Read more...
February 12, 2023

Other deep sky objects in Sagittarius

IC 4991 - Lenticular Galaxy in Sagittarius

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 emisphere.

IC 4991
Galaxy
Sagittarius
  • IC 4991 is below the horizon from Greenwich, United Kingdom [change]. See also rise and set times.
  • Given its B magnitude of 12.33, IC 4991 is visible with the help of a telescope havng 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
/>
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 [change]
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 [change]