Cosmic Leftovers

galex-view-m81_m82The Hubble Space Telescope has resolved some strange objects nicknamed “blue blobs” and found them to be brilliant blue clusters of stars born in the swirls and eddies of a galactic smashup 200 million years ago. These “blue blobs” exist along a wispy bridge of gas strung among three colliding galaxies, M81, M82, and NGC 3077 about 12 million light-years away from Earth. This is not a place astronomers expect to find star clusters because the gas filaments should be too thin to allow enough material to accumulate and actually build so many stars. The star clusters in this diffuse structure might have formed from gas collisions and subsequent turbulence which locally enhanced the density of the gas streams.

Image Credit: NASA, ESA

A Magnetic Cigar

This is a composite image of the Cigar Galaxy (aka M82), a starburst galaxy about 12 million light-years away in the constellation Ursa Major. It combines visible starlight (gray) and a tracing of hydrogen gas (red) from the Kitt Peak Observatory, with near-infrared and mid-infrared starlight and dust (yellow) from SOFIA (a NASA telescope mounted on 747 which does infrared astronomy flying above most of the atmosphere) and the Spitzer Space Telescope.. A magnetic field detected by SOFIA shows up in the image as streamlines which seem to follow the outflows (red) generated by the burst of star formation in the nucleus of the galaxy.

Image Credits: NASA / SOFIA / E. Lopez-Rodriguez and Spitzer / J. Moustakas et al.

Detecting a Supernova

Beforem82_uvot_before_sn_largeAfterm82_uvot_after_sn_large-arrow_0These Swift Ultraviolet optical telescope images show a galaxy called M82 before and after the new supernova. The pre-explosion view combines data taken between 2007 and 2013. The view showing SN 2014J (arrow) merges three exposures taken on 22 January, 2014. Mid-ultraviolet light is shown in blue, near-UV light in green, and visible light in red. The image is slightly more than half the apparent diameter of a full moon across.

This is a Type Ia supernova, the total destruction of a white dwarf star by one of two possible scenarios. In one, the white dwarf orbits a normal star, pulls a stream of matter from it, and gains mass until it reaches a critical threshold and explodes. In the other, the blast arises when two white dwarfs in a binary system eventually spiral inward and collide.

In either case, the explosion produces a superheated shell of plasma that expands outward into space at tens of millions of miles an hour. The interactions between the shell’s size, transparency and radioactive heating control when the supernova reaches peak brightness. Astronomers expect SN 2014J to continue brightening for a few more weeks. It may be visible in binocular by early February.

M82 (aka the Cigar Galaxy) is located in the constellation Ursa Major and is a popular target for small telescopes. It’s undergoing a period of extensive star formation that makes it many times brighter than our own Milky Way galaxy.

Image Credit: NASA

Blue Blobs, M81, and M82

galex-view-m81_m82The Hubble Space Telescope has resolved some strange objects nicknamed “blue blobs” and found them to be brilliant blue clusters of stars born in the swirls and eddies of a galactic smashup 200 million years ago. These “blue blobs” exist along a wispy bridge of gas strung among three colliding galaxies, M81, M82, and NGC 3077about 12 million light-years away from Earth. This is not a place astronomers expect to find star clusters because the gas filaments should be too thin to allow enough material to accumulate and actually build so many stars. The star clusters in this diffuse structure might have formed from gas collisions and subsequent turbulence which locally enhanced the density of the gas streams.

Image Credit: NASA, ESA

M82 on the Radio

m82_gbtThis composite image of starburst galaxy M82 shows the distribution of dense molecular gas as seen by the National Radio Astronomy Observatory’s 85-ft Green Bank Telescope (yellow and red) and the background stars and dust as seen by Hubble (blue). The yellow areas correspond to regions of intense star formation. The red areas trace outflows of gas from the disk of the galaxy.

Image Credit: NARO/NASA

A Pulsar in M82

M82 PulsarAstronomers have found a pulsating, dead star beaming with the energy of about 10 million greater than the Sun. A pulsar is a dense stellar remnant left over from a supernova explosion, and this one is the brightest pulsar ever recorded. The discovery was made using the Nuclear Spectroscopic Telescope Array, or NuSTAR. The pulsar is shown in pink at the center of the Messier 82 galaxy in this multi-wavelength image. NASA’s NuSTAR mission discovered the “pulse” of the pulsar using its high-energy X-ray vision.

Image Credit: NASA

Before and After

Beforem82_uvot_before_sn_largeAfterm82_uvot_after_sn_large-arrow_0These Swift Ultraviolet optical telescope images show a galaxy called M82 before and after the new supernova. The pre-explosion view combines data taken between 2007 and 2013. The view showing SN 2014J (arrow) merges three exposures taken on 22 January, 2014. Mid-ultraviolet light is shown in blue, near-UV light in green, and visible light in red. The image is slightly more than half the apparent diameter of a full moon across.

This is a Type Ia supernova, the total destruction of a white dwarf star by one of two possible scenarios. In one, the white dwarf orbits a normal star, pulls a stream of matter from it, and gains mass until it reaches a critical threshold and explodes. In the other, the blast arises when two white dwarfs in a binary system eventually spiral inward and collide.

In either case, the explosion produces a superheated shell of plasma that expands outward into space at tens of millions of miles an hour. The interactions between the shell’s size, transparency and radioactive heating control when the supernova reaches peak brightness. Astronomers expect SN 2014J to continue brightening for a few more weeks. It may be visible in binocular by early February.

M82 (aka the Cigar Galaxy) is located in the constellation Ursa Major and is a popular target for small telescopes. It’s undergoing a period of extensive star formation that makes it many times brighter than our own Milky Way galaxy.

Image Credit: NASA

Sometimes a Cigar Isn’t Just a Cigar

What’s lighting up the Cigar Galaxy? The galaxy, aka M82, was stirred up by a recent pass near the large spiral galaxy M81, but that doesn’t fully explain the source of the red-glowing outwardly expanding gas. Evidence indicates that this gas is being driven out by the combined particle winds flowing from many stars creating a galactic superwind. This picture is a mosaic of Hubble images highlighting a specific color of red light emitted by ionized hydrogen, showing detailed filaments of the gas. These filaments extend for over 10,000 light years. The Cigar Galaxy is the brightest galaxy in the sky in infrared light, and can be seen in visible light with a small telescope towards the constellation of the Great Bear (Ursa Major).

Image Credit: NASA