Supernova Imaged by Hubble Telescope

Delta Vel writes "First discovered by a Japanese amateur astronomer on July 31, this Type II supernova was imaged by Hubble on August 17th. The newly named SN 2004 dj, the closest supernova to be observed in over ten years, is about 11 million light-years away in the spiral galaxy NGC 2403. Looks like they goofed in one of the images, though--the arrow points to a different bright spot on the before-and-after image than it does on the main and annotated images." Reader Saeed al-Sahaf writes "Today, astronauts Gennady Padalka and Mike Fincke popped open the hatch on the Russian side of the ISS spacecraft and quickly stepped through the fourth and final spacewalk of their six-month mission. Their mission? Install three antennas and replace a 2-foot-square Russian pump panel. But of course, because it isn't a part or our Mission to Mars, it is still too dangerous work on the Hubble Telescope, which after all, is only used for science."

Comments

Article on UC Berkeley's website

[Anonymous Coward]

UC Berkeley's NewsCenter has a nice article about this. The astronomer is from UC Berkeley.

Re:Neato

[Anonymous Coward]

how exactly can they tell the difference?

Who said they could? Lol.

But seriously, I know the dynamic range of CCD's used telescopes can be at least 16 bits grayscale. To display them on a monitor/lcd you have to do some conversion. What basically look like very faint distinctions of shades of grey appear to be a detailed, crisp, starry picture of the sky to us (after conversion by the computer).

End result: They know that this white spec is ~100 times brighter than the white spec next to it, by looking at the raw intensity values observed from the camera.

p.s. Yes, I know that is a color image -- they probably took 3 grayscale images with red,green,and blue filters.

High Rez Goodness

[digitalgimpus]

Not for the dialup dudes, but great for broadband buddies:

http://imgsrc.hubblesite.org/hu/db/2004/23/images/ a/formats/full_jpg.jpg

Re:Neato

[Capt'n Hector]

The difference is, the "bigger looking one to the left" was there in the template image, and the supernova isn't. It's incredibly easy to tell the difference between SN and star. The hard part is telling the difference between a supernova and an asteroid. Luckily, the next night the astroid will have moved, and the supernova will have stayed.

But even if you weren't sure, the "wavelength/frequency" of the light is INCREDIBLY different. A good eye can tell the difference between all the different sorts of supernova spectra in seconds.

Educated guess, my ass.

By the way, I'm one of Filippenko's supernova checkers. Hi everybody!

-Harrison

The arrows are correct!!!!

[CyberBill]

They arrows are fine... You just have to realize that the first images have the majority of the galaxy cropped out... They are only showing NGC 2403-1, instead of the large NGC 2403.

Re:Political Comments not Nesissary

[Agent Orange]

Ok, I'll bite, rather than mod you -1 troll.

1) Age isn't necessarily a bad thing with a telescope. Lots of telescopes are a lot older than that - witness the Anglo-Australian Telescope, the UK Schmidt Telescope, and the recently burned-down Great Melbourne Telescope (aka MSSSO 50") which provided evidence that the universe is accelerating.

oh yeah, and hubble was launched on April 24, 1990 - you do the maths.

2) The replacement, the James Webb Space Telescope is optimised for the Infra-Red and can NOT operate in the blue/UV like hubble. Nor will it be launched until 2012, 4-5yrs *after* the prospective hubble death date.

JWST will also be at the L2 lagrange point, meaning that there is NO possibility of any servicing mission. here is info on the orbit.

3) There are NO better telescopes on the ground for imaging. Hubble has a *diffraction-limited* resolution of about 0.05" - 0.1" (0.05 - 0.1 arcsec). The BEST sites in the world (Mauna kea, cerro paranal) get seeing as good as 0.3-0.4" at the best of times, and that isn't too often.

No, adaptive optics do NOT help because they limit the field-of-view. Hubble has a diffraction limited FOV across the entire chip.

4) Hubble does not have to contend with atmospheric absorption, which makes observations in some bands (like the aforementioned UV) nigh on impossible.

Re:Super Novas & Nebulas are different critter

[CyberBill]

Messier object 1 (M1), more commonly known as the Crab Nebula, is a good example of a "Long ago" supernova remnant.
Crab Nebula Info
The star went supernova almost a thousand years ago, and that is whats left.

During the actual event of a supernova, though, the star (from so far away) only seems to go from being a normal star to an amazingly bright one, and then slowly dimming down over a few months (or years). The reason is because stars are so huge they cannot simply explode like in the movies, after all they are in a constant state of nuclear fusion!!

Re:I want to know if it will be visible with the..

[Soldrinero]

Type Ia supernovae take about a month to reach their peak brightness. While this is a Type II, a different class of explosion, I think the timescale is comparable. Accoring to this page the supernova had an apparent visual magnitude of 11.3 in early August. This is a factor of 100 dimmer than the naked eye can see under the best conditions (magnitude 6 is the dimmest the unaided eye can see).

If you're unsure of why a higher number means a dimmer object, or just want more information, czech out the Wikipedia entry on visual magnitudes.

By the way, the last supernova that was visible to the naked eye was SN1987A in the Large Magellanic Cloud.

Re:Nearby galaxy

[meringuoid]

There've been supernovae observed within our own Galaxy: the famous example is the Crab Nebula, whose supernova was recorded by Chinese astronomers in the 11th century, and was visible in daylight for months. There's a pulsar there now. There just haven't been any recently.

There are plenty of stars just itching to blow, though. Eta Carinae is about ready to pop, and Betelgeuse isn't far off. Either of these stars blow, we'll have a hell of a show.

Re:Still waiting...

[meringuoid]

Actually our sun does not have enough mass to go supernova. A star needs a mass about 1.4 times our own for it to go supernova, and this is called the Chandra Limit.

Close: it's the Chandrasekhar Limit.

It's not the star, but the core of the star that needs to exceed 1.4 solar masses. The Sun will eventually run out of hydrogen in its core, and fusion will end. The core will then be unsupported against its weight, and will contract and heat up dramatically. The increased heat will trigger nuclear fusion of helium, then the Sun switches on again. While the core's heating up, the increased temperature makes the outer layers balloon out to a huge volume, forming the red giant.

It's the core that's interesting, though. Eventually the helium runs out too, and we have a very dense gas of carbon. It contracts and heats up, but the Sun isn't big enough to reach carbon-burning temperatures. So the core can't support itself by burning to produce heat, and instead collapses until it's supported by 'degeneracy pressure' resulting from the fact that in quantum mechanics, no two electrons can occupy the same state.

The Chandrasekhar limit is the maximum mass that can be supported this way, and it's 1.4 solar masses. Get above that mass, the core of the dead star collapses, FAST. The next state down is the neutron star, held up by degeneracy between neutrons rather than electrons. All that matter falling at very high speed hits a core of hard neutronium and the fun starts. Lots and lots and lots of energy has got to go somewhere... the result being a star-shattering kaboom.