Owl Nebula
What is Owl Nebula?
Nebulae· Distance 2,000 ly. A planetary nebula below the bowl of the Big Dipper, staring out with two dark eyes like an owl's face — a round shell cast off by a dying star some 8,000 years ago, sharing a field with the galaxy M108. It never sets from Korea.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Owl Nebula is in your sky right now: https://nowsky.org/solar/sky?sel=owl nebula — location and time set automatically, no login.
Its place in the sky
A nebula, in the direction of Ursa Major, spanning about 3.4 arcminutes of sky — 0.1 times the width of the full Moon.
Distance and scale
| Distance | ~2,000 ly |
|---|---|
| Size | ~2 ly across |
| Type | planetary nebula |
| Constellation | Ursa Major |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Discovery and name
Lord Rosse drew its two dark "eyes" in 1848 and named it the Owl.
Frequently asked
- How far is Owl Nebula from Earth?
- ~2,000 ly.
- What kind of object is Owl Nebula?
- planetary nebula.
- Where in the sky is Owl Nebula?
- In the direction of Ursa Major.
- Where is Owl 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.
How 8,000 years was known — dating by expansion
The age of a planetary nebula comes from two values: the size of the shell and its expansion speed. The Owl's radius is about one light-year and the gas expands, by spectroscopy, at around 40 km/s; divide one by the other and the result is about 8,000 years since the central star began ejecting its envelope. In reality expansion starts slow and accelerates, so the age carries a large error and the qualifier "several thousand years".
The method sees only the shell spreading outward. How deep the nebula is along the line of sight follows from the expansion speed, but how wide it is depends on the distance, and the Owl's distance (about 2,000 light-years) is uncertain by 30 percent. That is why the same nebula's age ranges from 6,000 to 10,000 years across sources. Matching the direction of the two "eyes" to the expansion velocities even yields that the shell is a cylinder tilted 45° to our line of sight.
The nebula in depth
The Owl Nebula (M97) is a planetary nebula about 2,000 light-years away in Ursa Major. Pierre Méchain discovered it in 1781, and the name dates from 1848, when Lord Rosse sketched it through his great telescope and noted two dark holes like an owl's eyes. It is about two light-years wide and, at roughly 8,000 years, fairly old for a planetary nebula.
The nebula consists of three concentric shells. The two "eyes" are dark regions where a cylindrical cavity in the inner shell is seen at an angle. The central star is a 16th-magnitude white dwarf of about 120,000 K with only about 0.6 solar masses left. The gas expands at 30 to 40 km/s and amounts to roughly 0.15 solar masses.
In the Sky view, look between Merak and Phecda at the bottom of the Big Dipper's bowl, about 2° southeast of Merak. Circumpolar from Korea, it is always up and passes overhead on spring evenings. At magnitude 9.9 it is tough in binoculars, but a telescope of 15 cm or more with an O-III filter shows the round disk and the two eyes. The galaxy M108 sits nearby for a two-in-one view.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.