Around the World in 80 Telescopes
April 1, 2009
NGC 3359 – Meet Me at the Bar – Gemini North Image
This image of NGC 3359 was obtained with the Gemini Multi-Object Spectrograph (GMOS) on the Gemini North telescope on Mauna Kea in Hawai‘i. The circular pinwheel shape with the easily recognized spiral arm structure makes it straightforward to classify this object as a spiral galaxy, however, it is the presence of the straight ‘bar’ in the center of the galaxy that distinguishes NGC 3359 from many other spirals. Recent research has shown that the central bar in this galaxy is relatively young; it is only 500 million years old (as compared to the several billion year age of the galaxy). Astronomers are still trying to understand how large features like the bar form and how long they last as a galaxy like NGC 3359 evolves.
In addition to its central bar NGC 3359 is known for its many regions of star formation (so-called [H II] regions) that are visible across its disk. In this image the [H II] regions are seen as the light red patches visible throughout the image. There are approximately 100 [H II] regions in NGC 3359 which makes it an example of intense star formation. An example of an [H II] region in our own galaxy, where many tens of young stars have recently been born, is the famous Orion Nebula.
The color-composite image is actually made of four individual images taken in the g (blue), r (green), i (orange) and h-alpha (red) filters. NGC 3359 is a moderately large object in the sky. The angular size of this image is 4.3 x 5.3 arcminutes. It is a relatively close example of a spiral galaxy at a distance of roughly 49 million light-years. NGC 3359 is located in the constellation Ursa Major and has an apparent magnitude of 10.5. It is easily visible in amateur-sized portable telescopes.
NGC 3582 – The Heart of a Stellar Nursery – Gemini South Image
At the heart of a star-forming region called RCW 57 [see apod.nasa.gov/apod/ap080428.html], this image shows the complex interaction of interstellar gas and dark dust clouds among newly formed stars. The glowing gas is energized by ultraviolet radiation from the young stars.
The intricate wispy structures in the cloud are formed by radiation from the young stars and the explosions of nearby, very massive stars that have exceptionally short lives compared to stars like our sun. A study by M. Maercker in 2006 revealed that the region is overly abundant with massive star formation with over 33 star-forming regions in the extended area at the end stages of formation.
This region of the sky is only visible from observers in the southern hemisphere and is a popular showpiece for small telescopes and binoculars in the far-southern constellation of Carina.
The Gemini image was obtained with the Gemini Multi-Object Spectrograph at the Gemini South telescope using two pointings to make a mosaic image that has a field of view of 9.0 x 5.0 arcsminutes. The exposures were taken through three narrowband filters: [OIII] (blue), [SII] (green) and H-alpha (red).
Gemini North with Laser Guide Star
A 180-degree fisheye view of the Gemini North telescope on Mauna Kea, Hawai‘i lit by moonlight and the red glow of a passing automobile’s taillights shining through the wind-vent gates. At the top of the 7-story high telescope structure the laser guide star (LGS) can be seen propagating into the sky where it creates an artificial star used by an adaptive optics system to correct for distortions caused by turbulence in the Earth’s atmosphere.
Gemini South by Moonlight
The Gemini South telescope on Cerro Pachón in Chile is illuminated by the setting moon (visible on left, through vent-gate). At the bottom of this fisheye lens view, the Near-Infrared Cronagraphic Imager (NICI) is illuminated. NICI is currently being used extensively in planet-search programs due to its ability to see faint objects very close to bright stars. In the sky, the constellation of Orion dominates the open slit, it appears to be oriented in a Northern Hemisphere juxtaposition (with Orion’s head on top) but this is due to the fact that the lens used for this photograph shows the entire hemisphere of the sky and the top is really the back of the view.
- Peter Michaud
Gemini Observatory, Hilo HI, USA
(808) 974-2510 (desk)
(808) 937-0845 (cell)
On the nights of April 2-3 (3-4 UT) both Gemini telescopes participated in the “Around the World in 80 Telescopes” live, around the world control room webcast. Gemini was honored to be the first control room visit for the event when at 11:00 pm (HST) on April 2nd (9:00 am UT on April 3rd) Gemini presented a new video introduction to Gemini followed by a live visit to the Gemini North control room on Hawaii’s Mauna Kea hosted by Gemini’s Scott Fisher. Nineteen hours later, Gemini South participated in the event at Midnight (Chile time) on the night of April 3-4 (4:00 am UT on April 4th) when Gemini South astronomer Etienne Artigau hosted a visit to the Gemini South control room in Chile.
During each event a pair of new images were released which (along with the new “Introduction to the Gemini Observatory” video) can be seen and downloaded by clicking on the images at right.
For more information on this event and to see the archived video of the webcast see: 100HA website: http://www.100hoursofastronomy.org/