Nebulae
Emission Nebulae
compute location and get properties of a nebula
compare nebulae
get a property of a nebula
locate a nebula at a specified time
Planetary Nebulae
compute location and get properties of a planetary nebula
compare planetary nebulae
get a property of a planetary nebula
locate a planetary nebula at a specified time
Bright H II Regions
compute location and get properties of a bright H II region
compare H II regions
locate a bright H II region at a specified time