The terms alien abduction or abduction phenomenon describe "subjectively real memories of being taken secretly against one's will by apparently nonhuman entities and subjected to complex physical and psychological procedures".
 Such abductions have sometimes been classified as close encounters of the fourth kind.
 People claiming to have been abducted are usually called "abductees" or "experiencers".
The Close Encounters Tour was a concert tour by British recording artist, Robbie Williams.
 Running from April to December 2006, the tour supported Williams' sixth studio album, "Intensive Care".
 To date, it was the singer's largest tour, playing over 50 shows in Africa, Asia, Europe, the Americas and Australia.
 It is believed to have played to over 3 million spectators and earned over $60 million.
 The name is derived from the 1977 film, "Close Encounters of the Third Kind".
Encounters of the Spooky Kind () is a 1980 Hong Kong martial arts comedy horror film written and directed by Sammo Hung, who also starred in the lead role.
 The film was produced by Hung's production company Bo Ho Film Company.
 It was released as "Spooky Encounters" in the US.
 It is sometimes listed as "Close Encounters of the Spooky Kind", more blatantly mimicking the title of the film "Close Encounters of the Third Kind" (1977).
 The film was the progenitor of the jiangshi film genre and one of Hong Kong's first kung fu horror comedies.
An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age.
 More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist.
 They are loosely bound by mutual gravitational attraction and become disrupted by close encounters with other clusters and clouds of gas as they orbit the galactic center.
 This can result in a migration to the main body of the galaxy and a loss of cluster members through internal close encounters.
 Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years.
 In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer.
 Open clusters have been found only in spiral and irregular galaxies, in which active star formation is occurring.
Encounters of the Spooky Kind II is a 1990 Hong Kong martial arts comedy horror film produced, choreographed, starring Sammo Hung.
 The film was produced by Hung's production company, Bojon Films Company Ltd.
 It was released as "Spooky Encounters 2" in the US.
 It is sometimes listed as "aka Close Encounters of the Spooky Kind 2 ".
 Despite the title, the film is not a sequel to "Encounters of the Spooky Kind".
 The film's Chinese title literally translates as "Ghost Bites Ghost".
Cinematographer Vilmos Zsigmond, also formerly credited as William Zsigmond, was nominated for four Academy Awards for Best Cinematography ("Close Encounters of the Third Kind", "The Deer Hunter", "The River", and "The Black Dahlia"), winning once for his work on "Close Encounters of the Third Kind".
 He also won two American Society of Cinematographers Awards, one Primetime Emmy Award, and one British Academy Film Award.
Encounters Of Every Kind is an album by Meco, released in 1978.
 It was recorded after the success of Meco's platinum-selling album "Star Wars and Other Galactic Funk" and contains two sides of linked songs.
 In contrast to the previous album (which dedicated a full side to the music from "Star Wars") and contrary to an album title that suggests a similar focus on the music from "Close Encounters of the Third Kind", this album is actually made up of songs from a number of different popular movies, with no special focus on any particular film.
 (Meco would return to this format for his 1982 album "Pop Goes the Movies".)
 The music from "Close Encounters" only appears at the very end of the album.
In ufology, a close encounter is an event in which a person witnesses an unidentified flying object.
 This terminology and the system of classification behind it was started by astronomer and UFO researcher J. Allen Hynek, and was first suggested in his 1972 book "The UFO Experience: A Scientific Inquiry".
 He introduced the first three kinds of encounters; more sub-types of close encounters were later added by others, but these additional categories are not universally accepted by UFO researchers, mainly because they depart from the scientific rigor that Hynek aimed to bring to ufology.
Dr. Josef Allen Hynek (May 1, 1910 – April 27, 1986) was an American astronomer, professor, and ufologist.
 He is perhaps best remembered for his UFO research.
 Hynek acted as scientific advisor to UFO studies undertaken by the U.S. Air Force under three consecutive projects: Project Sign (1947–1949), Project Grudge (1949–1952), and Project Blue Book (1952–1969).
The Fourth Kind is a 2009 American science fiction horror film directed by Olatunde Osunsanmi and featuring a cast of Milla Jovovich, Elias Koteas, Corey Johnson, Will Patton, Charlotte Milchard, Mia Mckenna-Bruce, Yulian Vergov, and Olatunde Osunsanmi.
 The title is derived from the expansion of J. Allen Hynek's classification of close encounters with aliens, in which the fourth kind denotes alien abductions.

Question: When was the astronomer whose classification of close encounters with aliens was used to derive the title to "The Fourth Kind" born?
Answer: May 1, 1910