IC 1991 - Spiral Galaxy in Horologium
IC 1991 is a Spiral Galaxy in the Horologium constellation. IC 1991 is situated south of the celestial equator and, as such, it is more easily visible from the southern hemisphere. Given its B magnitude of 16.17, IC 1991 is visible only through long exposure photography.
The image below is a photograph of IC 1991 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).
Celestial Coordinates
Apparent
J2000
Finder Chart
The simplified sky charts below show the position of IC 1991 in the sky. The first chart has a field of view of 60° while the second one has a field of view of 10°.
Photometric Information
The following table lists the magnitude of IC 1991 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 1991.
Apparent Size
The following table reports IC 1991 apparent angular size. The green area displayed on top of the DSS2 image of IC 1991 is a visual representation of it.Morphological Classification
IC 1991 - Spiral Galaxy in Horologium is classified as Spiral (SAc) according to the Hubble and de Vaucouleurs galaxy morphological classification. The diagram below shows a visual representation of the position of IC 1991 - Spiral Galaxy in Horologium in the Hubble de Vaucouleurs sequence.
Credits for the background image: Antonio Ciccolella / M. De Leo / CC BY
Rise and Set Times
Location: Greenwich, UK
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London
IC 1991 - Spiral Galaxy in Horologium is currently not visible from Greenwich, UK