လျး-သၞာံ

လျး-သၞာံ
Map showing the stars that lie within 12.5 light-years of the Sun
တင်ဂၞင် ယူနေတ်
သၞောတ်ယူနေတ်	astronomy units
ယူနေတ် မဆေင်ကု	length
သင်္ကေတ	ly
အပြံင်အလှာဲ ယူနေတ်
1 ly in ...	... ဂှ် တုပ်သၟဟ် ကု ...
metric (SI) units	9.4607×1015 m    9.4607 Pm
imperial & US units	5.8786×1012 mi
astronomical units	63241 au    0.3066 pc

လျး-သၞာံ (light-year) ဂှ် ဒှ်ဗ္ၜတ် ဇမၠိင် သွက်ဂွံၜတ် ဗၞတ်ဗ္ၜတ် ဇမ္ၚောဲနက္သတ်တုဲ မွဲ လျး-သၞာံဂှ် နွံဒၟံင် ၜိုတ် ၉.၄၆ တြဳလဳယာန် ကဳလဝ်မဳတာ (9.46 x 10¹² km)၊ နကဵု တိုင်မ္ဂး နွံ ၅.၈၈ တြဳလဳယာန် တိုင် (5.88 x 10¹² mi)။ ပွံက်ဝွံ နကဵု သမဂ္ဂနက္သတ်ဂၠးကဝ် (International Astronomical Union (IAU)) ပံက်လဝ် နကဵု မဒုင်သဇိုင် မွဲလျး-သၞာံဂှ် ဒှ်ဇမ္ၚောဲ လျးမဒြေပ်စိုပ် ပ္ဍဲစမၠး အပ္ဍဲပွိုင်ကာလ မွဲသၞာံဂျူလဳယာန် (၃၆၅.၂၅ တ္ၚဲ) ရ။ ဟိုတ်နူ မအရေဝ် "သၞာံ"၊ နွံဒၟံင်တုဲ မအရေဝ်ဏအ်ဂှ် မလေပ်ကၠိုဟ်ဗၠေတ်စ ကုဗၞတ်ဗ္ၜတ်ကာလ ဒှ်မာန်ရ။ မဝေါဟာရ လျး-သၞာံ/လျးသၞာံ ဏအ်ဂှ် ကၠာဲလဝ် နူဘာသာအင်္ဂလိက် light-year ရ။ မအရေဝ်ဝေါဟာရ အင်္ဂလိက်ဂှ် "distance light travels in one year (ဇမ္ၚောဲ လျးမအာ ပ္ဍဲပွိုင်မွဲသၞာံ)" ဂှ် ညးကေတ် light (လျး) ကဵု year (သၞာံ) တုဲ ဗဒှ်လဝ် မဝေါဟာရဏအ်ရ။

ဗၞတ်ဗ္ၜတ်ဇမၠိင် လျး-တ္ၚဲဝွံ ဗွဲမဂၠိုင် စကာ ပ္ဍဲအခိင်ကာလ မၜတ် ဇမ္ၚောဲ အကြာ သၞံင် မွဲကုမွဲ ပ္ဍဲကဵု ဂလက်သဳရ။ ဗၞတ်ဗ္ၜတ် အကြာတၠပညာနက္သက်တအ် မစကာဂၠိုင်အိုတ်ဂှ် ဒှ်ပါသေက် (parsec) (နကဵုသင်္ကေတ: pc, မနွံ ၜိုတ် ၃.၂၆ လျး-သၞာံ၊ မဒှ်ဇမ္ၚောဲ မွဲဗၞတ်ဗ္ၜတ် နက္သက် ဒကဲ မွဲစက္က ဒဒက်တဴကဵု အာက် (the distance at which one astronomical unit subtends an angle of one second of arc)ရ။

ပွံက်

ပွံက် မပံက်လဝ် နကဵု သမဂ္ဂနက္သတ်ဂၠးကဝ် (IAU) ဝွံ ဗၞတ်ဗ္ၜတ် လျး-သၞာံ ဂှ် ဒုင်သဇိုင် ကုသၞာံဂျူလဳယာန် (၃၆၅.၂၅ တ္ၚဲ၊ တၞဟ်ခြာ ကု သၞာံဂြေဂဝ်ရဳယာန် နွံ ၃၆၅.၂၄၂၅ တ္ၚဲ) ကေုာံ ဒမြိပ်ပရဟ် လျး (၂၉၉ ၇၉၂ ၄၅၈)။ သွဟ်ဗၞတ်ဗ္ၜတ်ၜါဂှ် ပၠုပ်စုတ် ပ္ဍဲ IAU (1976) System of Astronomical Constants (သၞောတ် ကိုန်ဂစိုတ် လက္သတ်) တုဲ စကာကၠုင် နူကဵု သၞာံ ၁၉၈၄။ နကဵုဗွဲခမၞန်မ္ဂး သမဂ္ဂနက္သတ်ဂၠးကဝ်ဂှ် ညးတအ် စကာ ly။

• "ly" ဂှ် သွက် မွဲလျး-သၞာံ one light-year
• "kly" ဂှ် သွက် မွဲကဳလဝ်လျး-သၞာံ a kilolight-year (1,000 လျး-သၞာံ)
• "Mly" သွက် မွဲမဳဂါလျး-သၞာံ a megalight-year (1,000,000 လျး-သၞာံ)
• "Gly" သွက် မွဲဂဳဂါလျး-သၞာံ a gigalight-year (1,000,000,000 လျး-သၞာံ)

ဥပမာ

• လျးတ္ၚဲ မဒးဂိတုတုဲ နူဗလးမုက်ဂိတု ကလေင်တက်ကၠုင် ဂွံစိုပ်ဂၠးတိဂှ် ဒးကေတ်အခိင် လလအ် ၁.၃ စက္က (ဇမ္ၚောဲ နွံ ၄.၀၄ × ၁၀-၈ လျး-သၞာံ)။
• လျး နူတ္ၚဲ ဂွံစိုပ်ဂၠးတိဂှ် ဒးကေတ်အခိင် လလအ် ၈.၃ မိနေတ် (ဇမ္ၚောဲ နွံ ၁.၅၈ × ၁၀-၅ လျး-သၞာံ)
• လဒေါဝ်ဗဟဵု ဂလက်သဳပိုယ်, the Milky Way (ဂၠံင်သၟုဟ်နာ်) ဂှ် နွံဒၟံင် ဇမ္ၚောဲ ကဵုဂၠးတိ ၂၆.၀၀၀ လျး-သၞာံ။

လွပ် ဝေါဟာရ

List of orders of magnitude for length

Scale (ly)	Value	Item
10−9	4.04	Reflected sunlight from the Moon's surface takes 1.2–1.3 seconds to travel the distance to the Earth's surface (travelling roughly 350000 to 400000 kilometres).
10−6	1.58	One astronomical unit (the distance from the Sun to the Earth). It takes approximately 499 seconds (8.32 minutes) for light to travel this distance.
	1.27	The Huygens probe lands on Titan off Saturn and transmits images from its surface, 1.2 billion kilometres from Earth.
	5.04	New Horizons encounters Pluto at a distance of 4.7 billion kilometres, and the communication takes 4 hours 25 minutes to reach Earth.
10−3	2.04	The most distant space probe, Voyager 1, was about 18 light-hours away from the Earth As of October 2014[[Category:Articles containing potentially dated statements from ]]. It will take about 17500 years to reach one light-year at its current speed of about 17 km/s (38000) relative to the Sun. On September 12, 2013, NASA scientists announced that Voyager 1 had entered the interstellar medium of space on August 25, 2012, becoming the first manmade object to leave the Solar System.
	2.28	Voyager 1 as of October 2018, nearly 20 light-hours from the Earth
100	1.6	The Oort cloud is approximately two light-years in diameter. Its inner boundary is speculated to be at 50000, with its outer edge at 100000.
	2.0	Maximum extent of the Sun's gravitational dominance (Hill sphere/Roche sphere, 125000). Beyond this is the deep ex-solar gravitational interstellar medium.
	4.22	The nearest known star (other than the Sun), Proxima Centauri, is about 4.22 light-years away.
	8.6	Sirius, the brightest star of the night sky. Twice as massive and 25 times more luminous than the Sun, it outshines more luminous stars due to its relative proximity.
	1.19	HD 10700 e, an extrasolar candidate for a habitable planet. 6.6 times as massive as the earth, it is in the middle of the habitable zone of star Tau Ceti.
	2.05	Gliese 581, a red-dwarf star with several detectable exoplanets.
	3.1	Canopus, second in brightness in the terrestrial sky only to Sirius, a type A9 bright giant 10700 times more luminous than the Sun.
103	3	A0620-00, the second-nearest known black hole, is about 3000 light-years away.
	2.6	The centre of the Milky Way is about 26000 light-years away.
	1	The Milky Way is about 100000 light-years across.
	1.65	R136a1, in the Large Magellanic Cloud, the most luminous star known at 8.7 million times the luminosity of the Sun, has an apparent magnitude 12.77, just brighter than 3C 273.
106	2.5	The Andromeda Galaxy is approximately 2.5 million light-years away.
	3	The Triangulum Galaxy (M33), at about 3 million light-years away, is the most distant object visible to the naked eye.
	5.9	The nearest large galaxy cluster, the Virgo Cluster, is about 59 million light-years away.
	1.5 – 2.5	The Great Attractor lies at a distance of somewhere between 150 and 250 million light-years (the latter being the most recent estimate).
109	1.2	The Sloan Great Wall (not to be confused with Great Wall and Her–CrB GW) has been measured to be approximately one billion light-years distant.
	2.4	3C 273, optically the brightest quasar, of apparent magnitude 12.9, just dimmer than R136a1. 3C 273 is about 2.4 billion light-years away.
	4.57	The comoving distance from the Earth to the edge of the visible universe is about 45.7 billion light-years in any direction; this is the comoving radius of the observable universe. This is larger than the age of the universe dictated by the cosmic background radiation; see here for why this is possible.