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 hemisphere.
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.
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).
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.
Apparent size of IC 4991The 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.
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).
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.
Celestial coordinates and finder chart of IC 4991
Celestial coordinates for the J2000 equinox of IC 4991 are provided in the following table:
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°.