NGC 691 - Spiral Galaxy in Aries
NGC 691 is a Spiral Galaxy in the Aries constellation. NGC 691 is situated close to the celestial equator and, as such, it is at least partly visible from both hemispheres in certain times of the year.
Photometric information of NGC 691
The following table lists the magnitude of NGC 691 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 NGC 691.
Apparent size of NGC 691The following table reports NGC 691 apparent angular size. The green area displayed on top of the DSS2 image of NGC 691 is a visual representation of it.
Digitized Sky Survey image of NGC 691
The image below is a photograph of NGC 691 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).
NGC 691 - Spiral Galaxy in Aries morphological classification
NGC 691 - Spiral Galaxy in Aries is classified as Spiral (SAbc) according to the Hubble and de Vaucouleurs galaxy morphological classification. The diagram below shows a visual representation of the position of NGC 691 - Spiral Galaxy in Aries in the Hubble de Vaucouleurs sequence.
Celestial coordinates and finder chart of NGC 691
Celestial coordinates for the J2000 equinox of NGC 691 are provided in the following table:
The simplified sky charts below show the position of NGC 691 in the sky. The first chart has a field of view of 60° while the second one has a field of view of 10°.