NGC 6638 - Globular Cluster in Sagittarius
NGC 6638 is a Globular Cluster in the Sagittarius constellation. NGC 6638 is situated south of the celestial equator and, as such, it is more easily visible from the southern emisphere.
Photometric information of NGC 6638
The following table lists the magnitude of NGC 6638 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.
Apparent size of NGC 6638The following table reports NGC 6638 apparent angular size. The green area displayed on top of the DSS2 image of NGC 6638 is a visual representation of it.
Digitized Sky Survey image of NGC 6638
The image below is a photograph of NGC 6638 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).
Celestial coordinates and finder chart of NGC 6638
Celestial coordinates for the J2000 equinox of NGC 6638 are provided in the following table:
The simplified sky charts below show the position of NGC 6638 in the sky. The first chart has a field of view of 60° while the second one has a field of view of 10°.