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This new image from the ESO telescope in Chile shows what looks like a Chinese dragon in the sky. But really, it is NGC 5189 an S-shaped planetary nebula adorned with red and green cosmic fireworks. This dragon isn’t breathing fire – the colorful “smoke” is a signal that a star is dying.
At the end of its life, a star with a mass less than eight times that of the Sun will blow its outer layers away, giving rise to a planetary nebula. Some of these stellar puffballs are almost round, resembling huge soap bubbles or giant planets (hence the name), but others, such as NGC 5189 are more intricate.
In particular, this planetary nebula exhibits a curious “S”-shaped profile, with a central bar that is most likely the projection of an inner ring of gas discharged by the star, seen edge on. The details of the physical processes producing such a complex symmetry from a simple, spherical star are still the object of astronomical controversy. One possibility is that the star has a very close (but unseen) companion. Over time the orbits drift due to precession and this could result in the complex curves on the opposite sides of the star visible in this image.
This image has been taken with the New Technology Telescope at ESO’s La Silla Observatory in Chile, using the now decommissioned EMMI instrument. It is a combination of exposures taken through different narrowband filters, each designed to catch only the light coming from the glow of a given chemical element, namely hydrogen, oxygen and nitrogen.
Source: ESO
The Astronomy Picture Of the Day back in 1995 featured a similar color image of NGC 5189 taken by the 3.6m Anglo-Australian Telescope: http://antwrp.gsfc.nasa.gov/apod/ap951211.html . A wicked looking planetary nebula.
Ah, lovely. My favourite planetary nebula, whose common name is called “The Spiral Planetary.” Its remains an often relatively unknown planetaries in the sky because of it far southerly latitude, being placed in the constellation at declination of ?66 degrees.
Telescopically it looks exactly like this – an amazing site.
i’ve written heaps of research on this object.
Those who might be interested in the observational details might like to look at the webpageNGC 5189 (12056-6600) giving some history and open discussion.
Another fantastic closeup of this object taken by the 8.1m Gemini South telescope can be perused here: http://www.gemini.edu/gallery/v/astronomical_images_and_illustrations/album04/ngc5189MR.jpg.html . All are great images of this bizarre planetary nebula.
I should have said that this is actually a bipolar planetary nebula (BPNe), sometime described as a “late butterfly” in classification. The spiral shape are usually termed ansae, and demonstrates the so-called point-symmetry property, where features along the ansea appear mirrored. The whole nebula estimated mass is about 0.45 suns, and spans about 0.62 parsec or about 2 and-a-bit light-years
Distance is still not very well known, but it is around one kiloparsec (3,200 light years), with the lowest limits about 0.75 to 0.8 kiloparsecs.
The central star, or planetary nebula nucleus (PNN) is the variable star name KN Mus shining at 14.92B magnitude star and is classed as a white-dwarf ZZO-type variable with semi-regular periods that tentatively changes by as much as 0.04 magnitudes. (They display non-radially pulsations that change in their intrinsic brightness in periods from 30 seconds to 25 min and amplitudes from 0.001V to 0.2V magnitude. There is also been observed non-radial pulsations, whose period is given as about 690 seconds.) The PNN (HD 117622 / CSI-65-13298 / Gum 47). At 14th mag, this faint star lies closer but slightly SE of the nebulosity’s centre. (Slightly left and fractionally down from the centre of the spiral. (It looks slightly off-axis, about 75 to 80 degrees, so we are not quite looking perpendicular to the main axis.) Its central star’s temperature is about 100,000K.
iantresman said;
“Reminds me of the dragon-like V838 Monocerotis, though some people think it is more like a fox.”
V 838 Mon is believed to be a consequence of a nova ejection – being neither related to bipolar planetary nebulae or planetary nebulae.
Reminder to you. Don’t advertise your stuff, else your elusive (sic) dragon just runs out of puff.