Constellations Flashcards
Define constellations?
a group of stars that form an imaginary outline on the celestial sphere
How many recognized constellations are there in total?
88
How many recognized constellations are there in the northern hemisphere?
30
How many recognized constellations are there in the southern hemisphere?
32
How many recognized constellations are being shared by the 2 hemispheres and where are they located?
26, on the side of the celestial sphere
When did the star of Bethlehem last appear and how did it appear?
Last December 21, due to the conjunction of Saturn and Jupiter
How often does the star of Bethlehem appear?
Every 800 years
What is the star of Bethlehem also known as?
The Polaris or north star, which is the brightest star in the northern hemisphere
Describe the star of Bethlehem?
A supernova, which is a very bright light due to the explosion of supergiants
Describe the stone hedge?
It was used by neolithic people to study the day, month, and location of the earth as it revolves around the sun
How many ring positions are there in the stone hedge?
56 for the outermost, 30 for the middle, and 29 for the inner
Describe astronomy?
It is the study of the universe comprising of the planets, stars, galaxies, comets, and black holes
Describe the celestial sphere?
It is an imaginary bubble used to locate the position of heavenly bodies outside of earth. It is also concentric with earth meaning it shares the same center
What are heavenly bodies?
Stars, comets, and meteors
What is the celestial sphere also known as?
Galaxy
What is the size of the celestial sphere?
No specific size because it is not calculable
What are the 4 parts of the celestial sphere?
Celestial equator, North and South celestial poles, and Ecliptic
Describe the celestial equator?
Divides the north and south celestial poles
Which heavenly bodies do the Philippines see? Why?
All heavenly bodies located in the north celestial pole because the Philippines is located in the northern hemisphere
What is found in the north celestial pole?
Polaris, the brightest star in the northern hemisphere
Describe an ecliptic?
It is the path where the earth rotates on its axis
Describe a zenith?
It is the highest peak above our head on the celestial sphere
What is apart of the zenith? Describe.
Azimuth, which is the 360-degree surrounding
What are the degree measurements of the azimuth according to cardinal directions?
0: north, 90: east, 180: south, 270: west
Why do stars appear at night?
Because they generate their own light and this light is reflected by the atmosphere
Do stars twinkle?
No, they are just balls of gases and fire
What are the lit-up and twinkling objects in the sky?
Twinkling: stars, lit-up: planets
Where does the life cycle of stars begin?
It starts in the middle, which is the star-forming Nebula
How is a protostar made?
As hydrogen gases fuse due to gravity, they form helium gases and continue to fuse until they create a carbon core. From there, a protostar is produced
What happens if the protostar has a low fusion rate?
A low mass star would be produced and the life cycle will continue towards the left side
What happens if the protostar has a high fusion rate?
A high mass star would be produced and the life cycle will continue towards the right side
What are the characteristics of a low mass star?
Low pressure, fusion rate, temperature, cooler, and few amounts of gases accumulated
What are the characteristics of a high mass star?
High pressure, fusion rate, temperature, hotter, and more amounts of gases accumulated
What is the sun considered as?
Low mass star
How does the life cycle of a low mass star start?
From the low mass protostar, it will continue to accumulate gases making it bigger which will then enter the main sequence stage
How does the life cycle of a high mass star start?
From the high mass protostar, it will continue to accumulate gases making it bigger which will then enter the main sequence stage
What is the main sequence stage of a low mass star’s cycle and what does it turn to?
Sun-like star that turns in a giant
What is the main sequence stage of a high mass star’s cycle and what does it turn to?
Massive star, resulting in a supergiant due to the high pressure, fusion rate, and temperature
Low mass star: What forms after a giant? How?
Planetary nebula, because pressure and energy is used up, causing it to collapse
High mass star: What forms after a supergiant? How?
Supernova, because supergiant will explode due to massive pressure
Low mass star: What are the blue and orange looking fireworks do in the planetary nebula?
They are gases that fused which will spread and collapse
Low mass star: What happens after planetary nebula collapses?
The core of the planetary nebula will be the one left, forming a white dwarf
High mass star: What happens after a supernova is formed?
The supernova core can either turn into a black hole or a neutron star
Describe a black hole?
It is a hole in the ground
Describe a neutron star?
It is neither positively nor negatively charged
How does the life cycle of a low mass star restart?
The gases released from planetary nebula will repeat the cycle
How does the life cycle of a high mass star restart?
The debris of gases from the explosion will repeat the cycle
How many years does it take for the sun to turn into a white dwarf?
Millions of years
Recap the lifecycle of a low mass star?
- From low fusion rate protostar, it formed a low mass star
- Gathers gases making it bigger in size, turning into a sun-like star
- Turns into a giant as it grows bigger
- Turns into a planetary nebula as giant collapses due to pressure and energy being used up
- Planetary nebula will collapse and only the planetary nebula core would be left, forming a white dwarf
- Gases released from planetary nebula collapsing will repeat the cycle
Recap the lifecycle of a high mass star?
- From high fusion rate protostar, it formed a high mass star
- Gathers gases making it bigger in size, turning into a massive star
- Turns into a supergiant as it grows bigger
- Turns into a supernova as supergiant explodes
- Supernova core either turns into a black hole or a neutron star
- Debris of gases from explosion will repeat the cycle
How big is a high mass star?
8-10 times bigger than the sun
How are stars classified?
Color & temperature, Luminosity, and Size,
Describe type O?
Blue, hottest and brightest, 1st
Describe type B?
Blue white, 2nd
Describe type A?
White, 3rd
Describe type F?
Yellow white, 4th
Describe type G?
Yellow, 5th
Describe type K?
Orange, it is an intermediate between orange and red, sometimes it is also called brown. 6th
Describe type M?
Red, coolest and dimmest, 7th
What are the color types and corresponding temperatures of stars?
Blue: type O (hottest and brightest)
Blue white: type B
White: type A
Yellow white: type F
Yellow: type G
Orange: type K
Red: type M (coolest and dimmest)
What are the classifications of luminosity according to magnitude?
Absolute and apparent magnitude
Describe absolute magnitude?
It is the true brightness of a star at a standard distance of 32.6 light-years
Describe apparent magnitude?
It is the brightness of a star depending on the location and observer
Where and when is it best to go stargazing? Why?
During the night in a high area province because no light pollution is seen and the atmosphere is thinner
What are the 3 sizes of a star?
Supergiant, giant, and dwarf
What are the colors stars can come into?
Red, blue, yellow, and brown that appears purple
Describe the H-R Diagram?
Hertzsprung-Russell Diagram, a visual aid that shows connection of classification of stars
Describe the 3 evolutionary stages?
Age of stars in its lifecycle. Protostar, Main sequence, Ending star
Describe Tres Marias constellation?
Seen all throughout the Philippines at different locations depending on the month
What are the names of 3 stars part of Tres Marias?
Alnilam, Mintaka, and Alnitak
Describe Aquila constellation?
Eagle shaped
Describe Pegasus constellation?
Winged-horse shaped
Describe Ursa Major constellation?
Great big bear / Big dipper
Describe Ursa Minor constellation?
Small bear / Little dipper
Which constellation is Polaris star in?
Ursa Minor
Describe an asterism?
A star part of a constellation within a bigger constellation which spans across other constellations as well
What is an example of an asterism?
The Great Square
How are constellations and zodiac signs related?
On your birthday, you are aligned on the constellation while the sun is blocking the view
When should you look at your birthday constellation?
A month before your birthday so that the sun won’t block it
Which constellation is Tres Marias apart of?
Orion
