2014j

Supernova SN 2014J explodes

New data from NASA’s Chandra X-ray Observatory has provided stringent constraints on the environment around one of the closest supernovas discovered in decades. The Chandra results provide insight into possible cause of the explosion, as described in our press release. On January 21, 2014, astronomers witnessed a supernova soon after it exploded in the Messier 82, or M82, galaxy. Telescopes across the globe and in space turned their attention to study this newly exploded star, including Chandra.  Astronomers determined that this supernova, dubbed SN 2014J, belongs to a class of explosions called “Type Ia” supernovas. These supernovas are used as cosmic distance-markers and played a key role in the discovery of the Universe’s accelerated expansion, which has been attributed to the effects of dark energy.  Scientists think that all Type Ia supernovas involve the detonation of a white dwarf. One important question is whether the fuse on the explosion is lit when the white dwarf pulls too much material from a companion star like the Sun, or when two white dwarf stars merge. This image contains Chandra data, where low, medium, and high-energy X-rays are red, green, and blue respectively. The boxes in the bottom of the image show close-up views of the region around the supernova in data taken prior to the explosion (left), as well as data gathered on February 3, 2014, after the supernova went off (right).  The lack  of the detection of X-rays detected by Chandra is an important clue for astronomers looking for the exact mechanism of how this star exploded. The non-detection of X-rays reveals that the region around the site of the supernova explosion is relatively devoid of material. This finding is a critical clue to the origin of the explosion. Astronomers expect that if a white dwarf exploded because it had been steadily collecting matter from a companion star prior to exploding, the mass transfer process would not be 100% efficient, and the white dwarf would be immersed in a cloud of gas. If a significant amount of material were surrounding the doomed star, the blast wave generated by the supernova would have struck it by the time of the Chandra observation, producing a bright X-ray source. Since they do not detect any X-rays, the researchers determined that the region around SN 2014J is exceptionally clean. A viable candidate for the cause of SN 2014J must explain the relatively gas-free environment around the star prior to the explosion.  One possibility is the merger of two white dwarf stars, in which case there might have been little mass transfer and pollution of the environment before the explosion. Another is that several smaller eruptions on the surface of the white dwarf cleared the region prior to the supernova.  Further observations a few hundred days after the explosion could shed light on the amount of gas in a larger volume, and help decide between these and other scenarios.

Image credit: NASA/CXC/SAO/R.Margutti et al

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“Blank Space” and the Runway:

In Taylor Swift’s music video “Blank Space”, she satirizes the media’s portrayal of her as a serial dater. As her story progresses through the highs and lows of the relationship, she changes outfits in a whirlwind, clad in stunning gowns straight from the runway and from other designers. Here are the dresses from the runway that appear in her video:

  1. Dolce & Gabbana RTW F/W 2007
  2. Elie Saab RTW S/S 2014
  3. Jenny Packham RTW S/S 2014
  4. Oscar de la Renta RTW F/W 2014
  5. Naeem Khan RTW S/S 2014
  6. J. Mendel (unidentified season)
  7. Georges Chakra RTW S/S 2014

No X-rays from SN 2014J

Last January, telescopes in observatories around planet Earth were eagerly used to watch the rise of SN 2014J, a bright supernova in nearby galaxy M82. Still, the most important observations may have been from orbit where the Chandra X-ray Observatory saw nothing. Identified as a Type Ia supernova, the explosion of SN2014J was thought to be triggered by the buildup of mass on a white dwarf star steadily accreting material from a companion star. That model predicts X-rays would be generated when the supernova blastwave struck the material left surrounding the white dwarf. But no X-rays were seen from the supernova. The mostly blank close-ups centered on the supernova’s position are shown in the before and after inset panels of Chandra’s false color X-ray image of the M82 galaxy. The stunning lack of X-rays from SN 2014J will require astronomers to explore other models to explain what triggers these cosmic explosions.

Image credit: NASA / CXC / SAO / R. Margutti et al.

Spitzer stares into the heart of new supernova in M82

The closest supernova of its kind to be observed in the last few decades has sparked a global observing campaign involving legions of instruments on the ground and in space, including NASA’s Spitzer Space Telescope. With its dust-piercing infrared vision, Spitzer brings an important perspective to this effort by peering directly into the heart of the aftermath of the stellar explosion.

Dust in the supernova’s host galaxy M82, also called the “Cigar galaxy,” partially obscures observations in optical and high-energy forms of light. Spitzer can, therefore, complement all the other observatories taking part in painting a complete portrait of a once-in-a-generation supernova, which was first spotted in M82 on Jan. 21, 2014. A supernova is a tremendous explosion that marks the end of life for some stars.

“At this point in the supernova’s evolution, observations in infrared let us look the deepest into the event,” said Mansi Kasliwal, Hubble Fellow and Carnegie-Princeton Fellow at the Observatories of the Carnegie Institution for Science and the principal investigator for the Spitzer observations. “Spitzer is really good for bypassing the dust and nailing down what’s going on in and around the star system that spawned this supernova.”

Supernovas are among the most powerful events in the universe, releasing so much energy that a single outburst can outshine an entire galaxy. The new supernova, dubbed SN 2014J, is of a particular kind known as a Type Ia. This type of supernova results in the complete destruction of a white dwarf star-the small, dense, aged remnant of a typical star like our sun. Two scenarios are theorized to give rise to Type Ia supernovas. First, in a binary star system, a white dwarf gravitationally pulls in matter from its companion star, accruing mass until the white dwarf crosses a critical threshold and blows up. In the second, two white dwarfs in a binary system spiral inward toward each other and eventually collide explosively.

Type Ia supernovas serve a critically important role in gauging the expansion of the universe because they explode with almost exactly the same amount of energy, shining with a near-uniform peak brightness. The fainter a Type Ia supernova looks from our vantage point, the farther away it must be. Accordingly, Type Ia supernovas are referred to as “standard candles,” which allow astronomers to pin down the distances to nearby galaxies. Studying SN 2014J will help with understanding the processes behind Type Ia detonations to further refine theoretical models.

Image credit: NASA/JPL-Caltech/Carnegie Institution for Science

Starbursting in the Galaxy M82

Messier 82 (M82), the galaxy in which the nearest supernova in decades recently exploded, also is the closest galaxy that is undergoing a rapid burst of star formation, known as a starburst. About 12 million light-years away, it is seen nearly edge-on, as shown in the larger, visible-light image from the Hubble Space Telescope. The inset is a new radio image, made with the Karl G. Jansky Very Large Array (VLA), that reveals fresh information about the central 5200 light-years of the galaxy. The radio emission seen here is produced by ionized gas and by fast-moving electrons interacting with the interstellar magnetic field. The bright dots are a mix of star-forming regions and supernova remnants, the debris from stellar explosions; analysis of the VLA data tells scientists which of these are which. Scientists also are studying the faint, wispy features, many of which were previously unseen, to investigate their relationship with this galaxy’s starburst-driven superwind. Supernova 2014J is located outside the inset, to the right. VLA observations to date show that, like all other supernovae of its particular type, SN 2014J has not yet been found to be emitting radio waves.

Credit: Josh Marvil (NM Tech/NRAO), Bill Saxton (NRAO/AUI/NSF), NASA