4 ms·

An amateur astronomer became one of history’s greatest solar observers (2017)

24 points by Hooke 7y ago

mturmon 7y ago
What a nice article, that touches on a couple of issues in solar physics: o Because you have a big object, and a lot of photons, it's possible for amateur or less-equipped astronomers/departments to make a significant contribution. You can do a lot with a sub-1m telescope in a good location. o The solar cycle is 11 years, so in the career of a solar physicist, they might see 3 full solar cycles. You might work for a decade to get an instrument in orbit to observe, and see a solar cycle that is kind of underwhelming (like the just-ended solar cycle 24). o Given the above (time scale of instruments vs. Sun), there is a hard inter-calibration problem of critical time series like activity or irradiance. You need to keep consistent daily measurements over decadal time scales. This timebase spans the observing lifetime of telescopes, people, and even groups of people -- university groups come and go over a 30-year time span. Sunspot and active region determination is automated now, of course -- but this kind of historical record is really important. And, just because it's automated for one instrument, does not mean this carries over to the next one with different spatial resolution and spectral/temporal sampling.
ABeeSea 7y ago
Reminds me of how Kepler made his infamous discovery of elliptic orbits by staring at the data collected by his mentor Tycho Brahe. Without 20 years of detailed observations and calculations, Kepler probably would have either never come up with his theory or never have it taken seriously. And of course Newton’s principia devotes large portions to proving Kepler’s laws using Newton’s laws.
thechao 7y ago
Here are the first (1947) and last (1996) observations that are digitized. The last, one the spots are very faint, in the lower-right-hand side of the Sun. 1. https://www.kahaku.go.jp/research/db/science_engineering/sunspot/sketch/47/2kimg/s2k_j_470122.jpg https://www.kahaku.go.jp/research/db/science_engineering/sun... 2. https://www.kahaku.go.jp/research/db/science_engineering/sunspot/sketch/96/2kimg/s2k_j_961231.jpg https://www.kahaku.go.jp/research/db/science_engineering/sun...
- mturmon 7y ago
  Here is a movie of automatically-identified active regions covering 1996, as a comparative: http://jsoc.stanford.edu/data/mdi/mdi-tarp/mdi-browse/ql-mtarp/harp.mdi.fd_Marmask_1996.114_TAI_253d_mask.mp4 http://jsoc.stanford.edu/data/mdi/mdi-tarp/mdi-browse/ql-mta... This movie was made from the science data products, but it's just a browse product for convenience. See also: http://jsoc.stanford.edu/data/mdi/mdi-tarp/mdi-synoptic/ http://jsoc.stanford.edu/data/mdi/mdi-tarp/mdi-synoptic/ 1996/12/31 is in Carrington Rotation number 1917.

24 points by Hooke 7y ago

What a nice article, that touches on a couple of issues in solar physics: o Because you have a big object, and a lot of photons, it's possible for amateur or less-equipped astronomers/departments to make a significant contribution. You can do a lot with a sub-1m telescope in a good location. o The solar cycle is 11 years, so in the career of a solar physicist, they might see 3 full solar cycles. You might work for a decade to get an instrument in orbit to observe, and see a solar cycle that is kind of underwhelming (like the just-ended solar cycle 24). o Given the above (time scale of instruments vs. Sun), there is a hard inter-calibration problem of critical time series like activity or irradiance. You need to keep consistent daily measurements over decadal time scales. This timebase spans the observing lifetime of telescopes, people, and even groups of people -- university groups come and go over a 30-year time span. Sunspot and active region determination is automated now, of course -- but this kind of historical record is really important. And, just because it's automated for one instrument, does not mean this carries over to the next one with different spatial resolution and spectral/temporal sampling.

ABeeSea 7y ago

Reminds me of how Kepler made his infamous discovery of elliptic orbits by staring at the data collected by his mentor Tycho Brahe. Without 20 years of detailed observations and calculations, Kepler probably would have either never come up with his theory or never have it taken seriously. And of course Newton’s principia devotes large portions to proving Kepler’s laws using Newton’s laws.

thechao 7y ago

Here are the first (1947) and last (1996) observations that are digitized. The last, one the spots are very faint, in the lower-right-hand side of the Sun. 1. https://www.kahaku.go.jp/research/db/science_engineering/sunspot/sketch/47/2kimg/s2k_j_470122.jpg https://www.kahaku.go.jp/research/db/science_engineering/sun... 2. https://www.kahaku.go.jp/research/db/science_engineering/sunspot/sketch/96/2kimg/s2k_j_961231.jpg https://www.kahaku.go.jp/research/db/science_engineering/sun...

mturmon 7y ago
Here is a movie of automatically-identified active regions covering 1996, as a comparative: http://jsoc.stanford.edu/data/mdi/mdi-tarp/mdi-browse/ql-mtarp/harp.mdi.fd_Marmask_1996.114_TAI_253d_mask.mp4 http://jsoc.stanford.edu/data/mdi/mdi-tarp/mdi-browse/ql-mta... This movie was made from the science data products, but it's just a browse product for convenience. See also: http://jsoc.stanford.edu/data/mdi/mdi-tarp/mdi-synoptic/ http://jsoc.stanford.edu/data/mdi/mdi-tarp/mdi-synoptic/ 1996/12/31 is in Carrington Rotation number 1917.