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BEGIN:VEVENT
DTSTART;TZID=Atlantic/Canary:20211130T103000
DTEND;TZID=Atlantic/Canary:20211130T113000
UID:iactalks-1491
X-WR-CALNAME: IAC Talks: Open Astronomy Seminars
X-ORIGINAL-URL: /iactalks/Talks/view/1491
CREATED:2021-11-30T10:30:00+00:00
X-WR-CALDESC: IAC Talks upcomming talks
SUMMARY:MARK I: an astronomer's lifetime experiment
DESCRIPTION:MARK I: an astronomer's lifetime experiment\nProf. Teodoro Roca
  Cortés\n\nMark I is a part of the origin of the IAC, operating in the El
  Teide Observatory since 1975, in three different locations until reaching
  the Solar Pyramid "van der Raay" in 1987. Every day, weather permitting, 
 it has been providing precise measurements of the radial velocity of our s
 tar. It began to perform continuous daily observations from July 1984 and,
  until December 2020, 10169 out of 13408 possible days (76%) useful data h
 as been gathered. Designed, updated, maintained and operated by the Helios
 eismology team at the IAC and the University of Birmingham (UK), more than
  100 people, from TOTs and weekend fellows to professors, have contributed
  to this endeavour. It was a true pioneer, key in the birth and developmen
 t of Helioseismology and Astroseismology as branches of modern Astronomy.\
 n \nMark I is a resonant scattering spectrophotometer that measures t
 he radial velocity of integral sunlight using the KI-769.9 nm spectral lin
 e. It has been a pioneer and reference for calibration of other instrument
 s: MarkII, IRIS, Cannon, Stellar, Space, BiSON, GOLF, which have also work
 ed in different ground-based observatories and in space missions such as S
 oHO (1995-). \n \nIts precision, in a single measurement of the solar
  radial velocity, is less than 1 m/s, and the one achieved so far is less 
 than 1 cm/s at frequencies around 0.1 mHz (gravity modes zone) and less th
 an 1 mm/s at 3 mHz (acoustic modes zone). It measured for the first time t
 he spectrum of solar acoustic modes (from 1.8 to 4.2 mHz) of small degree 
 (ℓ <= 3): their frequencies, amplitudes and lifetimes, their rotation
 al splitting; also its variations with the cycle of solar activity. He has
  explored gravity modes, measured the spectrum's background, and determine
 d the acoustic cut-off frequency in the solar photosphere. All this has le
 d to numerous discoveries that have been published in around 40 doctoral t
 heses at different universities and more than 600 papers in international 
 journals and books. These works have been already cited around 10,000 time
 s in scientific literature.\n \nIn this talk I will briefly review it
 s history throughout more than 45 years, an entire academic life, and I wi
 ll raise some suggestions on its scientific use from now on.\n \n\n
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