Butterfly Nebula
What is Butterfly Nebula?
Nebulae· Distance 3,400 ly. Gas blown out in two directions by a dying star, spread like butterfly wings. Its central star, at 250,000 K one of the hottest known, stayed hidden for decades behind a thick dust belt. It lies near the tail of Scorpius in the southern sky.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Butterfly Nebula is in your sky right now: https://nowsky.org/solar/sky?sel=butterfly nebula — location and time set automatically, no login.
Its place in the sky
A nebula, in the direction of Scorpius, spanning about 3 arcminutes of sky — 0.1 times the width of the full Moon.
Distance and scale
| Distance | ~3,400 ly |
|---|---|
| Size | ~3 ly wingspan |
| Type | bipolar planetary nebula |
| Constellation | Scorpius |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Discovery and name
Its central star, at 250,000 K one of the hottest known, hides behind a thick dust torus.
Frequently asked
- How far is Butterfly Nebula from Earth?
- ~3,400 ly.
- What kind of object is Butterfly Nebula?
- bipolar planetary nebula.
- Where in the sky is Butterfly Nebula?
- In the direction of Scorpius.
- Where is Butterfly Nebula in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
Ice and carbonates inside the wings
The dust of the Butterfly turned up unexpected substances. Infrared spectroscopy found crystalline silicates together with water ice and carbonates — and carbonates, on Earth, are minerals that form only in liquid water. Since there can have been no liquid water around the star, the result implied a route to carbonates without water, and it prompted a rewrite of interstellar dust chemistry.
The dust is concentrated in a thick torus, a doughnut around the central star lying in its equatorial plane and blocking its light, so that gas escapes only along the poles and makes the butterfly's wings. The favoured reading is that the disk formed first through interaction with a companion before the star shed its envelope, and the velocities across the wings show the material was thrown out in a single event about 2,200 years ago.
The nebula in depth
The Butterfly Nebula (NGC 6302) is a bipolar planetary nebula about 3,400 light-years away in Scorpius. Its two wings span more than three light-years, with gas streaming outward at over 600 km/s. A thick belt of dust across the middle acts as the body that separates the wings. James Dunlop discovered it in 1826.
The central star was only seen in 2009, in Hubble's first images after its camera upgrade, when it finally showed through the dust. Its surface temperature of about 250,000 K makes it one of the hottest stars known — more than 40 times the Sun. Once a star of three to five solar masses, it has shed its outer layers and is cooling into a white dwarf. The dust belt contains crystalline ice, silicates and even carbonates, making the nebula chemically intriguing.
In the Sky view, look west of Shaula, the stinger of Scorpius, low in the south on summer evenings. At declination −37° it stays low from Korea, so a clear southern horizon is needed. At magnitude 9.5 a small telescope shows a tiny spindle; the wing detail appears only in large telescopes or photographs.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.