Visibility of astronomical objects during darkness

Fill in this form and press submit to obtain a plot with times where the given object is visible during darkness above certain angles above horizontal.

Optional name to be shown on plot:

Choose object by right ascension and declination (J2000):

R.A. = :: h:m:s and Dec. = :: deg:m:s

or choose the object by Galactic coordinates:

Long. = :: deg:m:s and Lat. = :: deg:m:s

Select the object by the coordinate system.

Choose the location of the obervatory:

  • Geographic latitude = :: deg:m:s
  • Geographic longitude = :: deg:m:s (positive east of Greenwhich)
  • Height = m above sea level.
Defaults are for Goellschau farm, Namibia (HESS site).

Choose the object altitude levels that you want to have displayed:

deg, deg, deg, deg above horizontal.
Moon time is .

Choose the time interval that you want to cover:

  • of
  • begin at . . (d.m.y) for days.

Your timezone is


In the resulting plot white corresponds to times where the sun is up, three grey levels correspond to civil, naval, and astronomical twilight, respectively, and yellow corresponds to times where the moon is up or making twilight. The times when the object is visible is indicated by up to four levels of blue. To use less levels, set the remaining levels to zero.


This service is provided at the Max-Planck-Institut für Kernphysik, Heidelberg.
Konrad. Bernloehr at mpi-hd. mpg. de