The Sun is an almost perfectly symmetric yellow dwarf star [spectral class G2V] which is at the center of our Solar System.
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1answer
269 views
Is there a simple yet accurate formula for where on Earth the Sun and Moon are directly overhead?
I'm trying to improve a site that shows the region of the Earth currently under daylight, and I
need a formula that, given the current time, tells where
(latitude/longitude) the sun and moon are ...
3
votes
0answers
86 views
Proton flux model or data at energy range up to 100 keV
I am looking for a model or at best the database of proton fluxes (solar p+) at a energy range of some eV up to 100 keV. I have already found the SOHO database:
http://umtof.umd.edu/pm/
But the ...
3
votes
0answers
59 views
Was Aristarchos' method to compute Earth-Sun distance ever rediscovered in medieval or modern times?
Ancient Greek astronomer Aristarchos who lived around 300 BC found a method to compute the Eart-Sun distance by applying geometry.
In this video about the cosmic distance ladder, at 26:30, Terence ...
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votes
0answers
384 views
live Kp index data
I need to create an online service displaying latest Kp index.
Where I can take the data?
The data should be in machine-readable format, i.e. text files, XML, or CGI gateways, for instance. No ...
2
votes
0answers
24 views
Surface UV exposure with cooler star
If the sun's surface was ~ 4000K (and earth closer to compensate), the UV component of the radiation would be less. However, UV makes ozone via photolysis of oxygen. Also, the stratosphere would ...
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votes
0answers
92 views
What is the Correlation Between Solar Wind Velocity/Density and Sunspot Count?
We have the Advanced Composition Exporer (ACE), which orbits in the L1 libration point as a source for solar wind velocity and density (particles/cm^3) data. Typically, at a velocity in the range of ...
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vote
0answers
54 views
Could Voyager 1 have entered a solar radiation belt?
We currently believe that the Sun has no radiation belts because the unstable magnetic field, which turns every 11 years, is not stable enough to sustain a solar radiation belt. But observations from ...
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0answers
21 views
Rosenberg-Coleman effect
I know only that it states some variations of the Sun's magnetic fields. What is the Rosenberg-Coleman effect specifically?
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14 views
How strong a solar flare needs to be to be easily seen on a projected white light image?
The first and the storgest solar flare so far is detected by simply projecting the Sun with optics on a paper. The flare was so intense that it was brighter than the photosphere beneath it.
Nowadays ...
