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SSE168°
ALT 28° · FOV 94°
🌟ByulGil
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Seoul
37°33′N · 126°58′E
2026.10.22 20:06
LIVE · 25 OF 40 ABOVE
Tonight's Sky
40 CONSTELLATIONS
constellation

Hercules

헤라클레스자리
The Keystone · The Hero
Summer · high in the eastern sky at night in May
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Science
The science

Hercules is the fifth-largest constellation in the sky, but with few bright stars, the trick is to first find the trapezoidal "Keystone" at its center. Along one side of this Keystone lies "M13," counted as the finest globular cluster of the northern hemisphere, a body of about 300,000 stars packed together like a ball, visible even to the naked eye as a faint glow. In 1974 the Arecibo radio telescope aimed at this very M13 to beam out the "Arecibo message," the first interstellar message sent to any alien civilization.

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Mythology
The myth

Hercules, born the son of Zeus, was the greatest hero of Greece. To atone for the crimes he committed in a madness inflicted by the goddess Hera's curse, he completed twelve labors, facing the Nemean Lion, the water serpent Hydra, and the dragon that guarded the golden apples, among others. In the sky he is drawn kneeling on one knee, his foot pressing down on the head of Draco, which for a long time earned him only the name "the Kneeler."

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Stars
Main stars (equatorial)
KornephorosRA 16.50h · Dec 21.5° · m2.8
ZetaRA 16.69h · Dec 31.6° · m2.8
PiRA 17.25h · Dec 36.8° · m3.2
EtaRA 16.71h · Dec 38.9° · m3.5
EpsilonRA 17.00h · Dec 30.9° · m3.9
SarinRA 17.25h · Dec 24.8° · m3.1
RasalgethiRA 17.24h · Dec 14.4° · m3.4
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Kalangitan sa Gabi nang Real-time

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Ang mga konstelasyong nasa itaas ng iyong ulo ngayon ay nagbabago bawat sandali ayon sa oras, petsa, at kung nasaan ka. Habang umiikot ang Earth, sumisikat ang mga bituin sa silangan at lumulubog sa kanluran; habang umiikot ang Earth sa Araw, nagbabago ang mga konstelasyong nakikita ayon sa panahon. Kinakalkula ng Byulgil ang tunay na kalangitan mula sa datos ng astronomiyang J2000.0 at iginuguhit ang mga konstelasyong nakikita mula sa iyong lokasyon ngayon bilang isang live na mapa at sa AR. Walang kailangang i-install — buksan lang ang iyong browser at tingnan ang langit ngayong gabi.

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40 Kuwento ng Konstelasyon

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Reading

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What is Byulgil?

Byulgil is a stargazing web app that computes the real night sky for your location, anywhere in the world, in real time. Byulgil means "Star Loads", in Korean. Use your current location (GPS) or pick a major city — Seoul, Tokyo, New York, Sydney — to see the sky exactly as it appears there, right now. Star positions come from real J2000.0 equatorial coordinates, converted to horizontal coordinates for your time and place. On mobile, AR mode lets you point your phone at the sky to overlay the constellations in that direction.