Browsing Astronomical Objects 
Aladin sky atlas
 Astronomical Objects in General 
Constellations Galaxies Messier Objects..... Nebulae, Planetary Supernovae Others.....
 Special Objects 
Meteorites
 Instruments
Hubble Space Telescope Radio-Telescopes Reflector Refractor
 Famous Astronomical Observatories
A - Z Mt. Palomar Mauna Kea: Keck
 Astronomical Organizations
A - Z
 Astronomical Organizations International
A - Z
 Astronomical Institutes in Europe
A - Z • xxx • yyy


OK, so let's which are presented in philatelic object in a hierarchical way  
click to show infos and options...
• you can Expand all or Collapse all
• use data of the  astrothesaurus2, as defined here: http://www.astrothesaurus.org
• browse by name A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
• browse by keywords A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z


Action ENTRY #found MEMO, Attributes and References
  Catalog Selection of Astronomical Catalogues for object displayed on stamps
  List_of_astronomical_catalogues
  Events Astronomical Events, e.g. eclipses, transits etc.
  Observation Astronomical Observation, Telescopes, Observatories etc.
  People Astronomers, People doing astronomical Research
  List_of_astronomers
  Research Astronomical Research, Congresses, Institutes, Societies etc.
  Universe All Astronomical Objects grouped by spatial relationships
INFO: use  to expand by one level or  to expand all below this level

  Click here to show some info about the hierarchical basis...
• the used hierarchical structure of themes is resulting from a mainly practical approach how to classify stamps
• a more scientific approach as a general astrothesaurus can be found,at astrothesaurus.org, look HERE
• a very charming approach is the classification in only 3 topics as OBSERVABLES / OBSERVERS / OBSERVATION, look HERE
• any member of a hierarchical level is member of the element(s) above (e.g. Mars is member of Planet, Planet is member of SolarSystem etc.)
•  .....