I saw this when looking at a National Geographic map of the universe. Also, what does GI, GJ, and LP stand for? I saw these stars on a map of stars in our “Our Sun’s Neighborhood.”
NGC = New Galactic Catalogue
I think it also has been called the New General Catalogue.
Both refer to astronomical objects as you’ve discovered. I have no idea about the other acronyms.
Now, after supper, I think I’m safe in correcting myself. The New General Catalogue is probably the more frequently used term. Here’s a link that describes the acronyms used in the NGC. None of the ones you saw seem to be listed.
IF (huge, unsubstantiated “if”) I am reading this Nomenclature of Celestial Objects - GJ page correctly, the two-character initials found near stars indicate the catalog (under the initials of the person maintaining it) where the star was first or best identified.
Gl (not GI) stood for W. Gliese. GJ stands for W. Gliese and H. Jahrweiss. LP stands for Luyten of the Palomar observatory.
You can look up any of those initials/abbreviations from the CDS (Centre de Données astronomiques de Strasbourg) Dictionary of Nomenclature of Celestial Objects search page.
I forgot this was sans serif: The Gl is G, lower-case L, not G, upper-case I.
There are numerous catalogs and naming systems for celestial objects. The acronyms you listed represent less common sets, with the possible exception of GI. Here are their definitions:
GJ = Gliese+Jahreiss - an extension of the Gliese catalog, commonly referred to as the “Nearby Star Catalog” or NSC
LP = Luyten, Palomar Observatory catalog - a proper motion survey from the 1960’s, useful in measuring the distance to nearby stars
GI = two possibilities. not a star catalog at all, but a spectral classification. It might also be an old-style designation from the Giclas catalog, which IIRC used the letter G followed by yet more letters. Unless you have an old star map, I’d go with the former explanation, especially if there are other designations like GIII, GIV, etc.
I should have picked that one right up! If they identified GJ objects from the extended catalog, sure enough they would probably include objects from the original GLiese catalog.