question: Which Greek astronomer first recorded the NGC 869 and 884 clusters?
answer: Hipparchus
context: Title: Double Cluster
  Passage: The Double Cluster (also known as Caldwell 14) is the common name for the open clusters NGC 869 and NGC 884 (often designated h Persei and χ Persei, respectively), which are close together in the constellation Perseus.  Both visible with the naked eye, NGC 869 and NGC 884 lie at a distance of 7500 light years.  NGC 869 has a mass of 3700 solar masses and NGC 884 weighs in at 2800 solar masses; however, later research has shown both clusters are surrounded with a very extensive halo of stars, with a total mass for the complex of at least 20,000 solar masses.  Based on their individual stars, the clusters are relatively young, both 12.8 million years old.  In comparison, the Pleiades have an estimated age ranging from 75 million years to 150 million years.  There are more than 300 blue-white super-giant stars in each of the clusters.  The clusters are also blueshifted, with NGC 869 approaching Earth at a speed of 39 km/s and NGC 884 approaching at a similar speed of 38 km/s .  Their hottest main sequence stars are of spectral type B0.
  Title: Perseus OB1
  Passage: Perseus OB1 is a OB association in the Northern Celestial Hemisphere in the constellation Perseus.  It contains the double cluster (NGC 869 and NGC 884), and has lent its name to the Perseus Arm of the Milky Way.
  Title: Messier 37
  Passage: Messier 37 (also known as "M37" or "NGC 2099") is the richest open cluster in the constellation Auriga.  It is the brightest of three open clusters in Auriga and was discovered by the Italian astronomer Giovanni Battista Hodierna before 1654.  M37 was missed by French astronomer Guillaume Le Gentil when he rediscovered M36 and M38 in 1749.  French astronomer Charles Messier independently rediscovered M37 in September 1764 but all three clusters were recorded by Hodierna.  It is classified as Trumpler type I,1,r or I,2,r.
  Title: Hipparchus
  Passage: Hipparchus of Nicaea ( ; Greek: Ἵππαρχος, "Hipparkhos" ;  ) was a Greek astronomer, geographer, and mathematician.  He is considered the founder of trigonometry but is most famous for his incidental discovery of precession of the equinoxes.
  Title: V520 Persei
  Passage: V520 Persei is a blue supergiant member of NGC 869, one of the Perseus Double Cluster open clusters.  It is an irregular variable star.
  Title: NGC 869
  Passage: NGC 869 is an open cluster located 7600 light years away in the constellation of Perseus.  The cluster is most likely around 13 million years old.  It is the westernmost of the Double Cluster with NGC 884.  NGC 869 and 884 are often designated h and χ Persei, respectively.  Located in the Perseus OB1 association both clusters are located physically close to one another, only a few hundred light years apart.  The clusters were first recorded by Hipparchus, but have likely been known since antiquity.
  Title: NGC 884
  Passage: NGC 884 is an open cluster located 7600 light years away in the constellation of Perseus.  It is the easternmost of the Double Cluster with NGC 869.  NGC 869 and 884 are often designated h and χ Persei, respectively.  The cluster is most likely around 12.5 million years old.  Located in the Perseus OB1 association, both clusters are located physically close to one another, only a few hundred light years apart.  The clusters were first recorded by Hipparchus, but have likely been known since antiquity.
  Title: S Persei
  Passage: S Persei is a red supergiant located near the Double Cluster in Perseus, north of the cluster NGC 869.  It is a member of the Perseus OB1 association and one of the largest known stars.  It is also a semiregular variable, a star whose variations are subject to more irregularities than those of Mira variables.
  Title: NGC 4623
  Passage: NGC 4623 is an edge-on lenticular or elliptical galaxy located about 54 million light-years away in the constellation of Virgo.  NGC 4623 is classified as an E7, a rare type of "late" elliptical that represents the first stage of transition into a lenticular galaxy.  NGC 4623 was discovered by astronomer William Herschel on April 13, 1784.  NGC 4623 is a member of the Virgo Cluster.
  Title: NGC 185
  Passage: NGC 185 (also known as Caldwell 18) is a dwarf spheroidal galaxy located 2.08 million light-years from Earth, appearing in the constellation Cassiopeia.  It is a member of the Local Group, and is a satellite of the Andromeda Galaxy (M31).  NGC 185 was discovered by William Herschel on November 30, 1787, and he cataloged it "H II.707".  John Herschel observed the object again in 1833 when he cataloged it as "h 35", and then in 1864 when he cataloged it as "GC 90" within his "General Catalogue of Nebulae and Clusters".  NGC 185 was first photographed between 1898 and 1900 by James Edward Keeler with the Crossley Reflector of Lick Observatory.  Unlike most dwarf elliptical galaxies, NGC 185 contains young stellar clusters, and star formation proceeded at a low rate until the recent past.  NGC 185 has an active galactic nucleus (AGN) and is usually classified as a type 2 Seyfert galaxy, though its status as a Seyfert is questioned.  It is possibly the closest Seyfert galaxy to Earth, and is the only known Seyfert in the Local Group.
citations: NGC 884 Hipparchus