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Stars and Constellations
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Email:[email protected]
1. ºÀUÀ®Ä gÁwæUÀ¼ÀÄ ºÉÃUÉ ¸ÀA¨sÀ«¸ÀÄvÀÛªÉ?
2. ««zsÀ IÄvÀÄUÀ¼ÀÄ ºÉÃUÉ ¸ÀA¨sÀ«¸ÀÄvÀÛªÉ?
3. £ÀPÀëvÀæ gÁ²UÀ¼ÉAzÀgÉãÀÄ?
PÉ®ªÀÅ ¥Àæ±ÉßUÀ¼ÀÄ
2
ºÀUÀ®Ä ªÀÄvÀÄÛ gÁwæUÀ¼ÀÄ
4
¨sÀÆ«ÄAiÀÄÄ vÀ£Àß CPÀëzÀ ¸ÀÄvÀÛ ¸ÀÄvÀÄÛªÀÅzÀjAzÀ ºÀUÀ®Ä gÁwæUÀ¼ÀÄ ¸ÀA¨sÀ«¸ÀÄvÀÛªÉ. ªÀÄvÀÄÛ
¨sÀÆ«ÄAiÀÄÄ ¸ÀÆAiÀÄð£À ¸ÀÄvÀÛ ¥Àj¨sÀæªÀÄuÉ ªÀiÁqÀĪÀÅzÀjAzÀ ««zsÀ IÄvÀÄUÀ¼ÀÄ ¸ÀA¨sÀ«¸ÀÄvÀÛªÉ.
««zsÀ IÄvÀÄUÀ¼ÀÄ
5
Earth’s axis of rotation is inclined to its orbital plane by 23.5°, which causes the seasons.
¸ÀÆAiÀÄð£À UÀÄgÀÄvÁéPÀµÀðuÉ §®ªÀÅ ¨sÀÆ«ÄAiÀÄ JgÀqÀÆ jÃwAiÀÄ ¥Àj¨sÀæªÀÄuÉUÉ PÁgÀtªÁVzÉ.
6
They are not related to Earth’s distance from the sun. In fact, Earth is slightly closer to the sun in (northern-hemisphere) winter than in summer.
Light from the sun
Steep incidence → Summer
Shallow incidence → Winter
The Seasons are only caused by a varying angle of incidence of the sun’s rays.
««zsÀ IÄvÀÄUÀ¼ÀÄ
8
1.DPÁ±À AiÀiÁªÀÅzÀjAzÀ ªÀiÁqÀ®ànÖzÉ?
DPÁ±ÀPÁAiÀÄUÀ½AzÀ DªÀÈvÀUÉÆArgÀĪÀ
MAzÀÄ ªÉÄïÁÒªÀt vÀ¯É ªÉÄðgÀĪÀ MAzÀÄ UÀĪÀÄäl ¨sÀÆ«ÄAiÀÄ£ÀÄß ¸ÀÄvÀÄÛªÀgÉ
¢gÀĪÀ MAzÀÄ UÉÆüÀ C£ÀAvÀ UÉÆüÀ
The Celestial Sphere (R UÉÆà ¼À)
11
•Geographic latitude l (northern hemisphere), you see the celestial north pole l degrees above the horizon.
•If l = 90⁰, then north pole will coincide the zenith.
l
The Celestial north pole
13
The Celestial South Pole is not visible from the northern hemisphere.
Celestial North Pole
12.300
Horizon
North South
Horizon
Mysore: l ≈ 12.3024º N
14
The Circling Sky Earth rotates from west
to east. The celestial sphere
appears to rotate east to west.
Apparent path of a particular star
In the Northern Hemisphere, stars near the North Celestial Pole are always above the horizon. Therefore, they are visible all time and they are called Circumpolar Stars
15
Different sets of constellations are visible in northern and southern skies.
The Altitude of the celestial pole (Polaris) = your latitude
Constellations £ÀPÀëvÀæ gÁ²UÀ¼ÀÄ
16
In ancient times,
constellations only referred
to the brightest stars that
appeared to form groups, representing mythological
figures.
Constellations £ÀPÀëvÀæ gÁ²UÀ¼ÀÄ
17
Today, constellations are well-defined regions on the sky, irrespective of the presence or absence of bright stars in those regions.
A constellation is any one of the 88 areas into which the sky is divided
18
How can we identify constellations in the night sky?
The use of a star chart can help us!
A STAR CHART is a map of the stars in the night sky.
19
Big DipperBig Dipper
Big dipper is a constellation which is a part of Ursa Major, the Great Bear. This is visible in the Northern Hemisphere all year long.
Pointer Stars
Arundhathi= Vasishta
Saptarishi Mandala
Kratu
Brighu
Modern names1.Atri2.Bharadvaja3.Gautama4.Jamadagni5.Kashyapa6.Vashista7.Vishvamitra
Counter-Clockwise Rotation
Clockwise Rotation
Northern Hemisphere Southern Hemisphere
The Altitude of the celestial pole (Polaris) = your latitude
28
Orion Not a circumpolar constellation, but a seasonal
constellationBetelgeuseBetelgeuse,, the right arm of Orion, glows with a dull red. RigelRigel,, in the opposite corner of the constellation, is blue and much brighter.
DjzÀæ
ªÀÄÈUÀ²gÀ
gÁd£Àå
ªÀĺÁªÁåzsÀ
29
Views of Orion from Tasmania (Australia) and Iran (Asia)
Northern hemisphere
Southern hemisphere
Orion from India
30
Ecliptic Constellations & Zodiac Signs A band of 12 constellations around the
sky entered on the ecliptic (apparent path of the sun on the earth as the earth revolves around it).
Born under the sign of…
Aries Libra
Taurus
Scorpio
Gemini
Sagittarius
Cancer
Capricorn
Leo Aquarius
Virgo Pisces
gÁ² (ªÀiÁ¸À)
gÁ² (ªÀiÁ¸À)
Aries ªÉÄõÀ (ZÉÊvÀæ)
Libra vÀįÁ (D±ÀéAiÀÄÄd)
Taurus
ªÀȵÀ¨sÀ (ªÉʱÁR)
Scorpio ªÀȲÑPÁ (PÁwÃðPÀ)
Gemini
«ÄxÀÄ£À (eÉõÀ×)
Sagittarius
zsÀ£ÀÄ (ªÀiÁUÀð²gÀ)
Cancer
PÀPÀðl (DµÁqsÀ)
Capricorn
ªÀÄPÀgÀ (¥ÀĵÀå)
Leo ¹AºÀ (±ÁæªÀt)
Aquarius PÀÄA¨sÀ (ªÀiÁWÀ)
Virgo PÀ£Àå (¨sÁzÀæ¥ÀzÀ)
Pisces «ÄãÀ (¥Á®ÄÎt)
Ecliptic Constellations & Zodiac Signs
55
1. What is changing at the same (annual) timescale that we are observing the changing zodiac?
Earth’s revolving.
2. Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year?
YES
3. Are the constellations themselves moving?
NO
4. What causes this apparent change in positions?
As Earth orbits the Sun, our perspective changes
5. Do all stars appear in different positions at different times of the year?
All except Polaris
6. Why is Polaris the only star that appears “fixed”?
Earth’s axis points to Polaris
Constellations