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Up for sale a RARE! "Dutch Astronomer" Peter van de Kamp Hand Signed 4X6 Card.
ES-4168E
Piet van de Kamp (December
26, 1901 in Kampen – May 18, 1995 in Amsterdam), known as Peter van de Kamp in the
United States, was a Dutch astronomer who lived in the United States most of his
life. He was professor of astronomy at Swarthmore College and
director of the college's Sproul Observatory from
1937 until 1972. He specialized in astrometry, studying parallax and proper motions of stars. He came to public attention in
the 1960s when he announced that Barnard's star had a planetary system based on observed
"wobbles" in of its motion, but this is now known to be false. On
November 14, 2018 the Red Dots project
announced that Barnard's star hosts
an exoplanet at least 3.2 times as massive as Earth. Van de Kamp was the son of
Lubbertus van de Kamp, who had an administrative job at a cigar factory, and
Engelina C.A. van der Wal. His younger brother Jacob van de Kamp was also a
successful scientist: an organic chemist, who spent most of his career in the
United States.[5] Van de Kamp studied at the University of Utrecht and
started his professional career at the Kapteyn Astronomical Institute in Groningen working with Pieter Johannes van Rhijn.
In 1923 he left for the Leander McCormick Observatory at
the University of Virginia for
a year's residence supported by the Draper Fund of the National Academy
of Sciences. There he assisted Samuel Alfred Mitchell with
his extensive stellar parallax program and Harold Alden with the lengthy Boss star project. The following year Van de Kamp went to
the Lick Observatory in
California as a Kellogg fellow. There he received his PhD from the University of California in
Astronomy in June 1925. The next year he also received a PhD from the University of Groningen.[1] Van de Kamp returned to McCormick on
October 1, 1925 to take up the position left vacant by Harold Alden, who had just taken up the directorship of
the Yale University Observatory Southern
Station in Johannesburg, South Africa. His work
consisted of assisting with the parallax program and continuing the proper
motion work that he and Alden had begun. Van de Kamp and Alexander N. Vyssotsky spent
eight years measuring 18,000 proper motions. He did additional, smaller
projects individually, including an investigation for general and
selective absorption of light within
the Milky Way. In the spring of 1937, Van de Kamp left McCormick
Observatory to take over as director of Swarthmore College's Sproul Observatory. There
he Star and in the 1960s reported a periodic
"wobble" in its motion, apparently due to planetary companions. It was not until several decades had
passed that a consensus had formed that this had been a spurious detection. In 1973 astronomers George Gatewood of the Allegheny the University of Florida,
using data obtained with improved equipment on the 30-inch Thaw Refractor
telescope, did not detect any planets but instead detected a change in the
color-dependent image scale of the images obtained from the 24-inch refractor
telescope at the Sproul Observatory used
by Van de Kamp in his study.[10] Astronomer John L. Hershey found
that this anomaly apparently occurred after each time the objective lens was removed, cleaned, and replaced.
Hundreds more stars showed "wobbles" like Barnard's Star's when photographs before and after cleaning
were compared – a virtual impossibility. Wulff Heintz, Van de Kamp's successor at Swarthmore and an
expert on double stars, questioned his findings and
began publishing criticisms from 1976 onwards; the two are reported to have
become estranged because of this. Van de Kamp never admitted that his
claim was in error and continued to publish papers about a planetary system
around Barnard's Star into
the 1980s, while modern radial velocity curves place a limit on the
planets much smaller than claimed by Van de Kamp Recent evidence suggests
that there is, indeed, a planet orbiting Barnard's Star, albeit of much lower
mass than Van de Kamp could have detected.
From
the 1940s on Van de Kamp and his staff made similar claims of planetary systems
around the nearby stars Lalande 21185, 61 Cygni, and many others, based on the same flawed
photographic plates. All of these claims have been refuted. However,
with the recent discoveries of numerous planetary systems, the idea that
planetary systems are common—of which throughout his life Van de Kamp was a
strong promoter—is being gradually proven correct.