question: Who is regarded as one of the most important astronomers of all time, and invented a morphological classification scheme for galaxies?
answer: Edwin Hubble
context: Title: Sextans B
  Passage: Sextans B (also known as UGC 5373 and DDO 70) is an irregular galaxy that may be part of the Local Group, or lie just beyond it.  Sextans B is 4.44 million light-years away from Earth and thus is one of the most distant members of the Local Group, if it is indeed a member.  It forms a pair with its neighbouring galaxy Sextans A.  It is a type Ir IV-V galaxy according to the galaxy morphological classification scheme.  Sextans B may also be gravitationally associated with the galaxies NGC 3109 and the Antlia Dwarf.
  Title: Lenticular galaxy
  Passage: A lenticular galaxy is a type of galaxy intermediate between an elliptical and a spiral galaxy in galaxy morphological classification schemes.  Lenticular galaxies are disc galaxies (like spiral galaxies) that have used up or lost most of their interstellar matter and therefore have very little ongoing star formation.  They may, however, retain significant dust in their disks.  As a result, they consist mainly of aging stars (like elliptical galaxies).  Because of their ill-defined spiral arms, if they are inclined face-on it is often difficult to distinguish between them and elliptical galaxies.  Despite the morphological differences, lenticular and elliptical galaxies share common properties like spectral features and scaling relations.  Both can be considered early-type galaxies that are passively evolving, at least in the local part of the Universe.
  Title: NGC 6286
  Passage: NGC 6286 is an interacting spiral galaxy located in the constellation Draco.  It is designated as Sb/P in the galaxy morphological classification scheme and was discovered by the American astronomer Lewis A. Swift on 13 August 1885.  NGC 6286 is located at about 252 million light years away from Earth.  NGC 6286 and NGC 6285 form a pair of interacting galaxies, with tidal distortions, categorized as Arp 293 in the Arp Atlas of Peculiar Galaxies. <ref name="NASA/IPAC"> </ref>
  Title: PhySH
  Passage: PhySH, an abbreviation for Physics Subject Headings, is a classification scheme developed by the American Physical Society (APS) as an universal classification scheme covering all branches of physics including astronomy, quantum computation, and physics education.  This scheme has been unveiled in January 2016.  It substitutes the previous Physics and Astronomy Classification Scheme (PACS) of the American Institute of Physics (AIP) and is currently the working tool for all journals of APS and all scientific Conferences and Meetings called by APS.
  Title: NGC 6000
  Passage: NGC 6000 is a barred spiral galaxy located in the constellation Scorpius.  It is designated as SB(s)bc in the galaxy morphological classification scheme and was discovered by John Herschel on 8 May 1834.  The galaxy is approximately 103 million light-years away.  It is the brightest of all the galaxies in the constellation Scorpius. <ref name="NASA/IPAC"> </ref><br>
  Title: Intermediate spiral galaxy
  Passage: An intermediate spiral galaxy is a galaxy that is in between the classifications of a barred spiral galaxy and an unbarred spiral galaxy.  It is designated as SAB in the galaxy morphological classification scheme.  By definition, a galaxy is a congregation of stars held together by gravity.  The first intermediate spiral galaxy discovered is the Milky Way, by Galileo, in 1610.  He was the first person with a telescope powerful enough to make such a discovery.  Before Galileo, it was thought that all bright objects in the sky were either the planets in the Solar System, moons, comets, or stars.  Until the beginning on the twentieth century, astronomers did not know the size of the Universe, but speculated it to be about as big as the Milky Way.  In 1920, at the National Academy of Science, there was a big debate between Harlow Shapley and Heber D. Curtis on whether nebulae are small globular clusters surrounding the Milky Way, or separate galaxies located farther away.  Nothing was resolved at the debate; neither side was able to provide conclusive evidence to prove their side correct over their opponent.  In 1923, Edwin Hubble resolved the matter with a photograph that he took of the Andromeda Galaxy.  What he found in his photograph was a very bright light source pulsing at a certain rate, a Cepheid variable, located outside the Milky Way.  This can be used to determine the distance to it.  Hubble proved that the Universe was full of galaxies, and disproved that the Milky Way was the extent of the Universe.  There are many types of galaxies in the Universe, elliptical, barred spiral galaxies; they vary in shape and size, but on average spiral galaxies are the most abundant.
  Title: Hubble sequence
  Passage: The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926.  It is often known colloquially as the Hubble tuning fork diagram because of the shape in which it is traditionally represented.
  Title: NGC 6285
  Passage: NGC 6285 is an interacting spiral galaxy located in the constellation Draco.  It is designated as S0-a in the galaxy morphological classification scheme and was discovered by the American astronomer Lewis A. Swift in 1886.  NGC 6285 is located at about 262 million light years away from earth.  NGC 6285 and NGC 6286 form a pair of interacting galaxies, with tidal distortions, categorized as Arp 293 in the Arp Atlas of Peculiar Galaxies<ref name="NASA/IPAC"> </ref>
  Title: Edwin Hubble
  Passage: Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer.  He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology and is regarded as one of the most important astronomers of all time.
  Title: Galaxy morphological classification
  Passage: Galaxy morphological classification is a system used by astronomers to divide galaxies into groups based on their visual appearance.  There are several schemes in use by which galaxies can be classified according to their morphologies, the most famous being the Hubble sequence, devised by Edwin Hubble and later expanded by Gérard de Vaucouleurs and Allan Sandage.
citations: Edwin Hubble Hubble sequence