among these neutrinos. They are roughly one third each of the three types of
antineutrino. See Sun.bright for related observations.
""")),
wind=Object(speed=Quantity.flat(.3, .8, .4, mega * metre / second),
# I suppose that's speed at the Sun or Earth and it slows on its
# way out (c.f. study.space.Kuiper.Heliosphere).
# TODO: check back on unfinished page, for composition:
# http://solarscience.msfc.nasa.gov/feature4.shtml
source="Corona"),
discovery=Discovery("the earliest life-forms", -3e9), # etym ?
density = 1.409 * kg / litre,
age = Quantity(4.6e9, year, # Peter Francis, age of solar system [missing error bar]
lifespan = 1e18 * second, # Nuffield, order of magnitude
# remain could include a further c. 2e9 years as a white dwarf
remain = Quantity.fromDecimal(5, 0, 9, year)),
magnitude = Quantity.flat(4.79, 4.83), # K&L, Moore
aliases = ('Sol',))
del load_rubble
# Common aliases for the atronomical unit (unit astronomique):
ua = AstronomicalUnit = AU = au
# Important derived unit:
parsec = Quantity(radian / arc.second, au,
doc="""The parsec - an astronomical unit of length.
The parsec is defined to be the distance at which one Astronomical Unit (q.v.)
subtends an angle of one second of arc (of which 3600 make one degree); this
makes it about a fifth of a million AU, which is about 3.26 light years.
surface=Spheroid(800 * mile),
# I haven't yet found radius ... but its eccentricity is low
orbit=Orbit(Sun, Float(4, 0, 9, mile), None, 0),
magnitude=18.5,
discovery=Discovery("Chadwick Trujillo and Michael Brown, of Caltech",
2002,
telescope="Palomar Oschin Schmidt",
note="""2002 LM60, a.k.a. Quaoar
Drs. Trujillo and Brown first observed this Kuiper Belt object, then (July 5,
August 1) had the Hubble Space Telescope take a closer look, to determine true
angular size, 40 * milli * arc.second. They named it after the creator-god of
the Tongva, the original inhabitants of the Los Angeles basin.\n"""))
# Even further out: beyond Kuiper, in the "inner Oort Cloud"
ape = Quantity(900, AU)
ape.observe(130 * tera * metre)
ape.observe(84 * giga * mile)
peri = About(76, 7, AU)
Sedna = MinorPlanet(
'Sedna',
surface=Spheroid(
About(950, 150, mile),
# surface temperature is "about" -400 F.
temperature=Fahrenheit(About(-400, 10)),
# it "likely rotates once every approximately 40 days"
#' suggesting that it's tidally locked to a moon
spin=Spin(About(40, 5, day))),
orbit=Orbit(Sun,
Quantity.flat(peri.low, ape.high, .5 * (ape.best + peri.best)),
Spin(10.5 * kilo * year),
