Monday, November 5, 2012

Astronomical Bodies: Moon Phases

amateur  astronomy series #2

Some astronomical bodies:

Milky Way (our galaxy)
Rotational velocity near the Sun 250 km/sec.
Rotational period near the Sun 225 million years.

Earth (our  Planet)A planet (from Ancient Greek αστήρ πλανήτης (astēr planētēs), meaning "wandering star") is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity,
Spin on axis 23h 56m 4.091s
Orbits  Sun in 365days 5hours 48minutes 45.51seconds
Equatorial rotational velocity .5 km/sec
Escape velocity 11.2 km/sec

Nebula: Celestial objects that are clouds of gas and dust and so can not be resolve into stars. They emit their light in a series of emission lines.

Ursa Minor (Constellation)
The yellow dashed lines are constellation boundaries, the red dashed line is the ecliptic, and the shades of blue show Milky Way areas of different brightness. The map contains all Messier objects, except for colliding ones. The underlying database contains all stars brighter than 6.5. All coordinates refer to equinox 2000.0.
The map is calculated with the equidistant azimuthal projection (the zenith being in the center of the image). The north pole is to the top. The (horizontal) lines of equal declination are drawn for 0°, ±10°, ±20° etc. The lines of equal right ascension are drawn for all 24 hours. Towards the rim there is a very slight magnification (and distortion).

distances from our earth is;
Polaris (431.42 light years),
Yildun (182.72 lght years),
E Umi (346.61 light years),
T Umi (375.76 light years),
Kocab (126.47 light years),
Pherkad (480.35 light years),
n Umi (97.30 light years).

Polaris facts;
14,000 years time.
47° away from celestial pole
(1°=3600 seconds of arc)


Aries:
(Mesarthim, Sheratan, Hamal, Mu, Ari).
is the first astrological sign in the Zodiac. It spans the 0-30th degree of the zodiac, between zero and 27.25 degree of celestial longitude, which the Sun transits this area on average between March 21 to April 19 each year.

Moon Phases (Moon as seen by an observer, usually on  Earth):

*new moon (Full in shadow),
*Waxing Crescent (Less than half is illuminated),
*First Quarter (Approximately half is illuminated),

*Waxing Gibbons (More than half is illuminated),
*full moon (Whole moon illuminated),
*Waning Gibbons (More than half is illuminated),
*Last Quarter (Appoximately half is illuminated),
*Waning Crescent ( Less than half is illuminated and this gets less each night).
*Note: all pictures thankfully shared from various sources..
geographic coordinate system

latitude (http://en.wikipedia.org/wiki/Latitude): (abbreviation: Lat., φ, or phi)
positive value represent North of the equator 
negative value represent South of the equator 

positive value represent East of the Greenwitch Meridian
negative value represent West of the Greenwitch Meridian

# A sum up to follow for details if required:

Solar System Extrasolar objects
Simple objects Compound objects Extended objects

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