Studying Orion with a Camera

ISS Underscores Orion

Orion is one of the most readily identifiable constellations in the night sky. Most visible in winter, when it’s a night-time feature of the sky, Orion is easily located via its triumvirate of aligned stars, known as Orion’s Belt.

Orion, Jupiter and Venus

Orion, Jupiter and Venus

In this first shot, Orion is left-of-frame, with Jupiter and Venus in close attendance with each other on the right.

In this second shot, the streak under Orion is the International Space Station, crossing completely under the massive constellation in a mere forty seconds.

ISS Underscores Orion

ISS Underscores Orion


Orion’s Stars

Surrounding Orion’s belt are four other stars, held to be Orion;s shoulders and feet. His highest shoulder (right, facing the observer) is the red supergiant Betelgeuse, some 640 light years from Earth. It is the eight-brightest star in the night sky. The blue giant Bellatrix is Orion’s left shoulder, and is maybe the 22nd brightest star in the sky (accounts vary).  It is a blue-white because it burns considerably hotter than the sun, and is only 250 light years from Earth. Orion’s left foot, Rigel, is the brightest star of the constellation, considered to be around 860 light years from Earth. Rigel is actually a binary system, with the Rigel B star’s brightness dwarfed by the A star. Saiph (Kappa Orionis) is reckoned to be around 650 light years from Earth, and is 22x larger than our Sun. Saiph is the sixth-brightest star in Orion, although the majority of Sapih’s brightness is in the ultraviolet spectrum, and thus not visible to the human eye.

Orion’s Belt

Orion’s Belt consists of Alnitak, Alnilam and Mintaka (left to right). Altitak is 100,000 times brighter than the sun. It is approximately 800 light years from Earth. Alnilam is much further away — estimated to be 1,340 light years from Earth. It emits most of its light in the ultraviolet spectrum, totalling 375,000x more brightness than the Sun. Mintaka is 915 light years away and is in fact a binary system, with its two stars orbiting each other every 5.73 days.

In this third shot, Orion’s Belt is the three stars in a line pointing towards the top-right of frame.

Orion's Belt and Orion's Sword

Orion’s Belt and Orion’s Sword

The camera has resolved a number of stars not visible with the naked eye, and although this shot is taken at a relatively low zoom range of just 260mm, the top and middle stars of Orion”s Sword are already clearly distinguishably multiple stars.

Orion’s Sword and the M42 Nebula

I set out on this post to take photos of Orion’s sword. This appears to hang down below his belt, and appears as three stars. However, it’s much more complex than that, and with the naked eye, the middle ‘star’ can be understood to be something else entirely. Indeed it is, the M42 nebula, held to be the most photographed nebula of all.

Orion's Sword at 520mm

Orion’s Sword at 520mm

At a 35mm focal length of 520mm, the lowest star is a singleton, the middle is a clear pair with a cloud surrounding it, and the upper star is a slightly more distant pair. The camera resolves a number of other stars not visible to the naked eye — at least not in a city with its light pollution.

Orion’s Sword and the M42 Nebula

Orion’s Sword and the M42 Nebula

Zooming in further (1,040mm) we can clearly see the gas/dust clouds of the Orion nebula (lower-right-middle of frame) surrounding the brightest star, Zeta Orionis. Clearly I have more to research regarding the many other stars that the camera has resolved. However, I’m quite pleased to have clearly captured my first ever nebula. That’s enough for tonight!

Camera geekery:¶

All shot with a Canon EOS 1d MkIII on a Manfrotto 190 ProB tripod with a 390RC2 head and a Canon TC-80N3 Remote Control.

    1. Lens: Canon EF16-35mm f/2.8L II. 16mm. Exposure: 1.3s @ F/3.5 ISO 1600
    2. Lens: Canon EF24-105mm f/4.0 L IS. 24mm. Exposure: 5 frames at 8s @ F/6.3 ISO 800
    3. Lens: Canon EF100-400mm f4.5-5.6L IS plus Extender EF 2x teleconverter. 200mm. 3.2s @ F/11 ISO 3200
    4. Lens: Canon EF400mm f/5.6 L. 400mm. 4s @ F/11 ISO 3200
    5. Lens: Canon EF400 F/5.6L plus EF2x teleconverter. 800mm. 1.6s @ F/11 ISO 3200

Note that the text refers to zoom lengths including the 1.3x crop factor of the 1d MkIII camera body.