The Orion Nebula is the easiest deep-sky object in the sky and the one most worth a look: a cloud of glowing gas 1,300 light-years away where stars are forming now, visible to the naked eye as a fuzzy star, striking in binoculars, and the best sight a small telescope can show. It hangs in Orion’s sword, just below the three belt stars, and from November onward it is in the evening sky for everyone on Earth. This guide gives the star-hop, the best hours and dark windows, what each instrument shows, and the detail to look for once you are there.

Where it is

Find Orion’s Belt: three bright stars in a short, straight, evenly spaced line, the most recognisable pattern in the winter sky. Below the belt (for northern observers) hangs the sword, a short vertical line of fainter stars. The middle “star” of the sword is not a star. To the naked eye it looks slightly fuzzy, as if out of focus; that is the nebula, catalogued as M42, with the whole sword region glowing faintly around it. From the southern hemisphere Orion stands on his head, so the sword points up from the belt, but it is the same line and the same fuzzy star in the middle.

When to look

Orion rises in the east in mid-evening in November and earlier each week after that. From Dallas the nebula is above the horizon from about 8:30 PM on November 14, 28 degrees up at 11 PM and 50 degrees high at 2 AM; by December 12 it is 15 degrees up at 8 PM and 51 degrees high at 1 AM; by mid-January it is at its best around 10 PM. Higher is better, because you look through less air, so aim for the hours around its highest point, which is roughly when it is due south.

The nebula is bright enough to survive some moonlight, but the faint outer wings need a dark sky. Moonless evening windows in the next two months: November 9 to 16, when the Moon sets before midnight; and December 1 to 15, from last quarter to just past new moon on December 8. The moon calendar shows the moonset time for your city on any night.

What each instrument shows

  • Naked eye: a soft, slightly extended glow in place of the sword’s middle star, magnitude 4, obvious from the country and visible from a suburb once your eyes have adapted for ten minutes. Use averted vision, looking a little to one side.
  • Binoculars, 7x to 10x: a distinct misty patch with a bright core, several stars embedded in it, and a hint of the fan shape. The whole sword fits in the field, with the smaller glow of M43 just above the main cloud and the loose cluster of the Running Man nebula above that.
  • Small telescope, 60 to 100 mm at 40x to 80x: the show. A bright central region with the Trapezium, four tight stars in a tiny quadrilateral that are the young suns lighting the cloud; two great curving wings of nebulosity spreading from it like a bird; a dark notch, the Fish’s Mouth, cutting into the bright core; and a faint greenish tint to the brightest part, the only deep-sky colour most eyes can detect.
  • Larger telescope, 200 mm and up: the wings stretch across half a degree, the dark lanes and bright ridges multiply, the Trapezium shows a fifth and sixth star in steady air, and the colour deepens. Many observers consider it the finest telescopic object in the sky.

Low power beats high power here. The nebula is large, more than a degree across in long photographs, and a wide field at 40x shows more than a cramped view at 200x. Save the high power for the Trapezium.

What you are looking at

The Orion Nebula is a region of star formation about 24 light-years across, the brightest part of a far larger cloud of gas and dust that covers most of the constellation. The gas glows because the four Trapezium stars, each tens of times the mass of the Sun and only a few hundred thousand years old, flood it with ultraviolet light. Hidden inside, infrared telescopes have found hundreds of newborn stars still wrapped in the dust they formed from, and discs of material around some of them that will become planetary systems. Its distance, about 1,344 light-years by the best radio measurements, means the light reaching your eye tonight left the cloud around the end of the seventh century. It is the nearest place to us where massive stars are being born, and the reason astronomers study it so intensely.

Photographing it

The nebula is the easiest deep-sky object to photograph. A phone on a tripod in night mode, or a camera at ISO 1600 for 10 to 20 seconds with a 50 mm lens, shows the glow and the pink-red colour that the eye cannot see; a 200 mm lens or a small telescope with a camera attached shows the wings and the dust. Keep exposures short to avoid trailing, stack a dozen frames, and shoot when the nebula is highest. Our guide to photographing a meteor shower covers the same camera basics.

While you are in Orion

Betelgeuse, the red-orange star at the shoulder, and Rigel, the blue-white star at the foot, are two of the brightest stars in the sky and show their colours to the naked eye. The belt itself is a fine binocular field. Follow the belt down and left to Sirius, the brightest star of all, rising a couple of hours after Orion. And this winter the planets add to the scene: Uranus near the Pleiades to the upper right of Orion, and Jupiter and Mars rising in Leo after midnight. Our guide to finding the Pleiades covers the cluster that leads Orion across the sky.