Announcements

1
Announcements

• Exam 2 will be returned next time
• The last 1st Quarter Night is in one week
  Tuesday April 15. Make plans to attend
• The last exam will be the final exam Wednesday
  April 30 _at_ 130pm Will cover chapters 7 8 I
  dont expect to get to Chapter 9
• Research paper Presentations will begin Monday
  April 21
• Dont forget the planetarium test!!! Observations
  is 15 of the grade 10 for planetarium test

2
The rise of solar astronomy
3
Joseph Fraunhofer had measured the solar spectrum
in 1814
4
By the 1850, Gustav Kirchhoff and Robert Bunsen
had identified many of the lines in the solar
spectrum
5
Kirchhoff developed the science of spectroscopic
analysis
Kirchhoffs 1st Law a hot solid or dense gas
will emit a continuous spectrum of light whose
peak wavelength depends on the temperature Kirchho
ffs 2nd Law a cool gas will absorb specific
wavelengths of light dependent on the elements
present in the gas. Kirchhoffs 3rd Law a hot
gas will emit specific wavelengths of light
dependent on the elements present in the gas.
6
Julius Plucker studied the spectra of gas
discharge tubes
7
Anders Angstrom published a detailed compendium
of the spectral lines in the sun in 1868
8
In 1843 Heinrich Schwabe announced the discovery
of a cycle in the number of sunspots
9
The Naturalist Alexander von Humboldt drew
attention to Schwabes cycle in Kosmos
10
Humboldt had encouraged scientists around the
world to map the Earths magnetic field
Many of the geomagnetic observatories were
started under Humboldts encouragement
11
What they discovered is the Earths magnetic
field isnt constant
The Earths magnetic field seemed to vary with
the same periodicity as the sunspot cycle.
12
In 1859 Richard Hodgson and R. C. Carrington made
the first observation of a solar flare
13
Eclipse chasing was how observers viewed the
suns atmosphere
14
Flash Spectra of the sun at eclipse showed a
layer called the chromosphere
15
J. Norman Lockyer was the first to attach a
spectrograph to a telescope for solar observations
16
Pierre Janssen discovered helium in the solar
spectrum
17
Simultaneously, Lockyer published a paper on
helium using the same technique
18
Others though there were even more new elements
in the sun
The green color was thought to be due to
coronium. We now know it is due to Fe XIV and Ni
XVI
19
Henry Draper was one of the earliest
astrophotographers