New Concepts: All sky survey, Extragalactic objects, High redshift surveys, etc

[katieefrey]

Name & Describe the new concepts

1. all sky survey
   UAT currently has "Sky surveys," suggesting a more specific concept that specifies surveys of the whole sky.

2. Extragalactic Objects
   broader concept to describe extragalctic objects, things in space that are not otherwise known. would fit somewhere under "extragalactic astronomy"

3. high redshift surveys
   the UAT currently has "Redshift surveys," so this is a suggestion for a more specific concept regarding high redshifts

4. Blue objects

5. Hot stars

6. Nonstellar

7. Nearby Galaxies

8. Aurora

Please include any additional comments/feedback
Comment suggested by Markus Demleitner as part of his work mapping IVOA and UAT concepts.

[katieefrey]

4. Hot stars is already an NPT of "Early-type stars"

[katieefrey]

Aurorae added (see #334)

[BartlettAstro]

@ebortey could you please split this the concepts listed here into multiple individual issues? Any specific suggestions with regards to a concept should be repeated in the new issue. The new issues should refer back to this one and should include "Comment suggested by Markus Demleitner as part of his work mapping IVOA and UAT concepts." In addition, add a comment to this issue identifying the new issues and their concepts.
Neither Aurorae nor Hot stars need their own issues.

[ebortey]

For all sky survey see issue #429
For extragalactic objects see issue #430
For high redshift surveys see issue #431
For blue objects see issue #432
For nonstellar see issue #437
For nearby galaxies see issue #438