Masquerading as a double star
The object in this image is Jonckheere 900 or J 900, a planetary nebula — glowing shells of ionised gas pushed out by a dying star. Discovered in the early 1900s by astronomer Robert Jonckheere, the dusty nebula is small but fairly bright, with a relatively evenly spread central region surrounded by soft wispy edges.
Despite the clarity of this Hubble image, the two objects in the picture above can be confusing for observers. J 900’s nearby companion, a faint star in the constellation of Gemini, often causes problems for observers because it is so close to the nebula — when seeing conditions are bad, this star seems to merge into J 900, giving it an elongated appearance. Hubble’s position above the Earth’s atmosphere means that this is not an issue for the space telescope.
Astronomers have also mistakenly reported observations of a double star in place of these two objects, as the planetary nebula is quite small and compact.
J 900’s central star is only just visible in this image, and is very faint — fainter than the nebula’s neighbour. The nebula appears to display a bipolar structure, where there are two distinct lobes of material emanating from its centre, enclosed by a bright oval disc.
A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Josh Barrington.
Credit:ESA/Hubble & NASA
Acknowledgement: Josh Barrington
About the Image
Id: | potw1312a |
Type: | Observation |
Release date: | 25 March 2013, 10:00 |
Size: | 568 x 586 px |
About the Object
Name: | Jonckheere 900, PN G194.2+02.5 |
Type: | Milky Way : Nebula : Type : Planetary |
Constellation: | Gemini |
Category: | Nebulae |
Wallpapers
Coordinates
Position (RA): | 6 25 57.13 |
Position (Dec): | 17° 47' 27.94" |
Field of view: | 0.47 x 0.49 arcminutes |
Orientation: | North is 46.1° right of vertical |
Colours & filters
Band | Wavelength | Telescope |
---|---|---|
Optical O III | 502 nm |
Hubble Space Telescope
WFPC2 |
Optical V | 555 nm |
Hubble Space Telescope
WFC2 |
Optical H-alpha | 658 nm |
Hubble Space Telescope
WFPC2 |