I recently saw a Digg article which linked to a space.com page about the 10 Strangest Things in Space. All but 2 of the items were not pictures at all but computer simulations, or artists impressions. So here to correct this injustice to phenomena everywhere I present the REAL 10 Strangest Things in Space - or at least in my opinion. Feel free to suggest any others in the comments.
V838 Monoceroti Expansion (Hubble)
It wasn’t anything interesting until it happened but the star V838 Monoceroti, which had simply sat in obscurity, flared up in 2002 to become 600,000 more luminous than our own Sun. It didn’t take long for the star to fade back into the darkness but the Hubble Space Telescope managed to get quite a few pictures of it during its active phase. (Click for animated version)
In this series of images you can see how the star’s outer layers were first expelled and then cut away by the powerful radiation from the star. The event was made even more interesting by the fact that a ‘light echo‘ was seen. During the expansion the object appeared to expand faster than the speed of light - the effect was however merely an astronomical optical illusion.
The Egg Nebula (Hubble)
Also known as CRL2688, the Egg Nebula shows a pair of mysterious ’searchlights’ bursting out from a dense cocoon of dust surrounding a hidden, Sun-like star. We see the light escaping in the directions where the cocoon is thinner. Objects like CRL2688 are rare because they are in a phase of their evolution that is short-lived. Images like this one are very important to understanding how stars like our Sun will ultimately die.
The Sun in UV (SOHO)
The surface of the Sun is far more active than most people would think. This ultraviolet video taken by NASA’s SOHO spacecraft gives brilliant detail. It allows us to see one full revolution of the Sun on its axis, which normally takes about 25 days. In this video you can make out large flares erupting from the surface and the striking magnetic loops that seem to whirl about them as they go. (Full 512×512 MPEG Here)
Red Square Nebula Nebula (Hale/Keck)
Discovered in 2007, this ruby-like nebula may be the result of two interacting stars. If one star is dying then the material from it may be dragged into a disc around the orbits of both objects. Material can then only escape from the system along the poles of the disc, resulting in two cones leading out of the stars. When viewed from the edge these cones seem like two triangles. Here the system is seen in the infrared. Structures like this are rarely seen in nebula but there is in fact a Red Rectangle Nebula which is less symmetric but still quite interesting to look at.
Abell 39 (NOAO)
Here we see an almost perfect planetary nebula that sits about 7,000 light years away in the constellation Hercules. The dot at the centre is the original star, which - as it died - released the expanding gas shell also seen clearly here. The ghostly appearance of the shell is due to the blue-green filter used to take the image, which picks out the oxygen emitted light at 500.7nm.
Saturn’s Rings (Cassini)
This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. Cassini was sheltered from the Sun’s glare by positioning itself behind Saturn. Ring structures are revealed here in detail as they brighten substantially at viewing angles where the Sun is almost directly behind the objects. These observations allowed Cassini to detected two new faint rings.
The Horsehead Nebula Swallowed Something (SCUBA)
Observers used the JCMT submillimetre telescope on Mauna Kea in Hawaii to take this image of the familiar Horsehead Nebula, who’s outline can be seen here. When observed at 850 microns, we are seeing the cold dust at temperatures close to absolute zero. This dust is deep inside the optical nebula normally seen, which is transparent at this wavelength. It seems from the image that the Horse has swallowed a ‘lozenge’ which is in fact a region of dense dust that may be collapsing under gravity. In fact this could be a star system in the making.
Gomez’s Hamburger (Hubble)
Arturo Gomez found this odd object in 1985 and it became known as Gomez’s Hamburger for obvious reasons. It is actually a proto-planetary nebula, an earlier version of Abell 39 perhaps. The curves of light (the bun) are reflecting light from the star which is being obscured by a thick band of dust (the burger). The whole thing is only only a fraction of a light year across and located 10,000 light years away in Sagittarius.
The Solar Spectrum (NOAO)
If you could catch a rainbow and put it under a microscope you would see that it was not a continuous blend of colours. Along the width of it would be seen, scattered irregularly, dark patches. Atoms and molecules in the Sun’s atmosphere pick out specific frequencies of light and absorb them, diminishing their intensity by comparison. This images shows the spectrum of light from the Sun stretched out to make these absorption lines visible. We use the reverse of the idea (emission lines) when we make coloured lights. For instance, we excite sodium atoms to emit a signature orange light in street lamps. In this image you can see two prominent dark bands in the yellow-orange section which are the absorption due to sodium.
Update to This Entry
The Sombrero Galaxy in Infrared (Spitzer)
By looking at things in different wavelengths we can see much more than meets the eye. This image is a perfect example. Just as with the Horsehead image above we are seeing cooler material. This time it is dust in the Sombrero galaxy. The red ring is a thick band of dust encircling the whole galaxy. In the optical, this dust ring is what gives the Sombrero its distinctive black, obscuring line.
Oddities in the Orion Nebula (Hubble)
Deep within high resolution images of the Orion Nebula taken by Hubble we can see dark blobs. When you take a closer look you can see that these are like little flattened blobs. Some show a dim, red glow at their centres, others are just dark. These are proto solar-systems.
The red glowing is a protostars attempting to burst through and the dark disks are thick dust regions where one day planets may form. 6 billion years ago, this is what our Solar System may have looked from very far away.
