{ "id": 11608, "url": "https://svs.gsfc.nasa.gov/11608/", "page_type": "Produced Video", "title": "Fermi Reveals Novae as a New Class of Gamma-Ray Sources", "description": "Observations of four stellar eruptions, called novae, by NASA's Fermi Gamma-ray Space Telescope firmly establish that these relatively common outbursts nearly always produce gamma rays, the most energetic form of light. A nova is a sudden, short-lived brightening of an otherwise inconspicuous star caused by a thermonuclear explosion on the surface of a white dwarf, a compact star not much larger than Earth. Novae occur because a stream of gas flowing from the star continually piles up into a layer on the white dwarf's surface. This layer eventually reaches a flash point and detonates in a runaway thermonuclear explosion. Each nova releases up to 100,000 times the annual energy output of our sun. Prior to Fermi, no one suspected these outbursts were capable of producing high-energy gamma rays. Such emission, with energies millions of times greater than visible light, usually is associated with far more powerful cosmic blasts.Fermi's Large Area Telescope (LAT) scored its first nova detection in March 2010 with an outburst of V407 Cygni. In this rare type of system, a white dwarf interacts with a red giant star more than a hundred times the size of our sun. Other members of this unusual stellar class have been observed to \"go nova\" every few decades.In 2012 and 2013, the LAT found three much more typical, or \"classical,\" novae: V339 Delphini in 2013 and V1324 Scorpii and V959 Monocerotis in 2012. The outbursts occurred in comparatively common systems where a white dwarf and a sun-like star orbit each other every few hours. Astronomers estimate that between 20 and 50 novae occur each year in our galaxy. Most go undetected, their visible light obscured by intervening dust and their gamma rays dimmed by distance. All of the gamma-ray novae found so far lie between 9,000 and 15,000 light-years away, which is relatively nearby compared to our galaxy's size.One explanation for the gamma-ray emission is that the blast creates multiple shock waves, which expand into space at slightly different speeds. Faster shocks could interact with slower ones, accelerating particles to near the speed of light. These particles ultimately could produce gamma rays. || ", "release_date": "2014-07-31T14:00:00-04:00", "update_date": "2023-05-03T13:50:41.381707-04:00", "main_image": { "id": 453314, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Fermi_novae_large_no_labels_searchweb.png", "filename": "Fermi_novae_large_no_labels_searchweb.png", "media_type": "Image", "alt_text": "Same as above but without labels.Credit: NASA/DOE/Fermi LAT Collaboration", "width": 320, "height": 180, "pixels": 57600 }, "main_video": null, "main_credits": { "Written by": [ { "name": "Francis Reddy", "employer": "University of Maryland College Park" } ] }, "progress": "Complete", "media_groups": [ { "id": 340571, "url": "https://svs.gsfc.nasa.gov/11608/#media_group_340571", "widget": "Basic text with HTML", "title": "", "caption": "", "description": "Observations of four stellar eruptions, called novae, by NASA's Fermi Gamma-ray Space Telescope firmly establish that these relatively common outbursts nearly always produce gamma rays, the most energetic form of light.

A nova is a sudden, short-lived brightening of an otherwise inconspicuous star caused by a thermonuclear explosion on the surface of a white dwarf, a compact star not much larger than Earth. Novae occur because a stream of gas flowing from the star continually piles up into a layer on the white dwarf's surface. This layer eventually reaches a flash point and detonates in a runaway thermonuclear explosion.

Each nova releases up to 100,000 times the annual energy output of our sun. Prior to Fermi, no one suspected these outbursts were capable of producing high-energy gamma rays. Such emission, with energies millions of times greater than visible light, usually is associated with far more powerful cosmic blasts.

Fermi's Large Area Telescope (LAT) scored its first nova detection in March 2010 with an outburst of V407 Cygni. In this rare type of system, a white dwarf interacts with a red giant star more than a hundred times the size of our sun. Other members of this unusual stellar class have been observed to \"go nova\" every few decades.

In 2012 and 2013, the LAT found three much more typical, or \"classical,\" novae: V339 Delphini in 2013 and V1324 Scorpii and V959 Monocerotis in 2012. The outbursts occurred in comparatively common systems where a white dwarf and a sun-like star orbit each other every few hours.

Astronomers estimate that between 20 and 50 novae occur each year in our galaxy. Most go undetected, their visible light obscured by intervening dust and their gamma rays dimmed by distance. All of the gamma-ray novae found so far lie between 9,000 and 15,000 light-years away, which is relatively nearby compared to our galaxy's size.

One explanation for the gamma-ray emission is that the blast creates multiple shock waves, which expand into space at slightly different speeds. Faster shocks could interact with slower ones, accelerating particles to near the speed of light. These particles ultimately could produce gamma rays.", "items": [], "extra_data": {} }, { "id": 340572, "url": "https://svs.gsfc.nasa.gov/11608/#media_group_340572", "widget": "Single image", "title": "", "caption": "", "description": "The white dwarf star in V407 Cygni, shown here in an artist's concept, went nova in 2010. Scientists think the outburst primarily emitted gamma rays (magenta) as the blast wave plowed through the gas-rich environment near the system's red giant star.

Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "items": [ { "id": 290265, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453301, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/V407_Cyg_Nova_Final_print.jpg", "filename": "V407_Cyg_Nova_Final_print.jpg", "media_type": "Image", "alt_text": "The white dwarf star in V407 Cygni, shown here in an artist's concept, went nova in 2010. Scientists think the outburst primarily emitted gamma rays (magenta) as the blast wave plowed through the gas-rich environment near the system's red giant star. Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 1024, "height": 768, "pixels": 786432 } }, { "id": 290263, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453299, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/V407_Cyg_Nova_Final.jpg", "filename": "V407_Cyg_Nova_Final.jpg", "media_type": "Image", "alt_text": "The white dwarf star in V407 Cygni, shown here in an artist's concept, went nova in 2010. Scientists think the outburst primarily emitted gamma rays (magenta) as the blast wave plowed through the gas-rich environment near the system's red giant star. Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 4000, "height": 3000, "pixels": 12000000 } }, { "id": 290262, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453303, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/V407_Cyg_Nova_Final_print_thm.png", "filename": "V407_Cyg_Nova_Final_print_thm.png", "media_type": "Image", "alt_text": "The white dwarf star in V407 Cygni, shown here in an artist's concept, went nova in 2010. Scientists think the outburst primarily emitted gamma rays (magenta) as the blast wave plowed through the gas-rich environment near the system's red giant star. Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 80, "height": 40, "pixels": 3200 } }, { "id": 290266, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453302, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/V407_Cyg_Nova_Final_web.png", "filename": "V407_Cyg_Nova_Final_web.png", "media_type": "Image", "alt_text": "The white dwarf star in V407 Cygni, shown here in an artist's concept, went nova in 2010. Scientists think the outburst primarily emitted gamma rays (magenta) as the blast wave plowed through the gas-rich environment near the system's red giant star. Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 320, "height": 240, "pixels": 76800 } }, { "id": 290267, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453304, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/V407_Cyg_Nova_Final_searchweb.png", "filename": "V407_Cyg_Nova_Final_searchweb.png", "media_type": "Image", "alt_text": "The white dwarf star in V407 Cygni, shown here in an artist's concept, went nova in 2010. Scientists think the outburst primarily emitted gamma rays (magenta) as the blast wave plowed through the gas-rich environment near the system's red giant star. Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 320, "height": 180, "pixels": 57600 } }, { "id": 290264, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453300, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/V407_Cyg_Nova_Final.tiff", "filename": "V407_Cyg_Nova_Final.tiff", "media_type": "Image", "alt_text": "The white dwarf star in V407 Cygni, shown here in an artist's concept, went nova in 2010. Scientists think the outburst primarily emitted gamma rays (magenta) as the blast wave plowed through the gas-rich environment near the system's red giant star. Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 4000, "height": 3000, "pixels": 12000000 } } ], "extra_data": {} }, { "id": 340573, "url": "https://svs.gsfc.nasa.gov/11608/#media_group_340573", "widget": "Single image", "title": "", "caption": "", "description": "Novae typically originate in binary systems containing sun-like stars, as shown in this artist's rendering. A nova in a system like this likely produces gamma rays (magenta) through collisions among multiple shock waves in the rapidly expanding shell of debris.

Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "items": [ { "id": 290270, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453307, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Classical_Nova_Final_print.jpg", "filename": "Classical_Nova_Final_print.jpg", "media_type": "Image", "alt_text": "Novae typically originate in binary systems containing sun-like stars, as shown in this artist's rendering. A nova in a system like this likely produces gamma rays (magenta) through collisions among multiple shock waves in the rapidly expanding shell of debris.Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 1024, "height": 768, "pixels": 786432 } }, { "id": 290269, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453306, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Classical_Nova_Final.jpg", "filename": "Classical_Nova_Final.jpg", "media_type": "Image", "alt_text": "Novae typically originate in binary systems containing sun-like stars, as shown in this artist's rendering. A nova in a system like this likely produces gamma rays (magenta) through collisions among multiple shock waves in the rapidly expanding shell of debris.Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 4000, "height": 3000, "pixels": 12000000 } }, { "id": 290271, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453308, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Classical_Nova_Final_web.png", "filename": "Classical_Nova_Final_web.png", "media_type": "Image", "alt_text": "Novae typically originate in binary systems containing sun-like stars, as shown in this artist's rendering. A nova in a system like this likely produces gamma rays (magenta) through collisions among multiple shock waves in the rapidly expanding shell of debris.Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 320, "height": 240, "pixels": 76800 } }, { "id": 290268, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453305, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Classical_Nova_Final.tiff", "filename": "Classical_Nova_Final.tiff", "media_type": "Image", "alt_text": "Novae typically originate in binary systems containing sun-like stars, as shown in this artist's rendering. A nova in a system like this likely produces gamma rays (magenta) through collisions among multiple shock waves in the rapidly expanding shell of debris.Credit: NASA's Goddard Space Flight Center/S. Wiessinger", "width": 4000, "height": 3000, "pixels": 12000000 } } ], "extra_data": {} }, { "id": 340574, "url": "https://svs.gsfc.nasa.gov/11608/#media_group_340574", "widget": "Single image", "title": "", "caption": "", "description": "These images show Fermi data centered on each of the four gamma-ray novae observed by the LAT. Colors indicate the number of detected gamma rays with energies greater than 100 million electron volts (blue indicates lowest, yellow highest).

Credit: NASA/DOE/Fermi LAT Collaboration", "items": [ { "id": 290273, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453310, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Fermi_novae_small_labels.jpg", "filename": "Fermi_novae_small_labels.jpg", "media_type": "Image", "alt_text": "These images show Fermi data centered on each of the four gamma-ray novae observed by the LAT. Colors indicate the number of detected gamma rays with energies greater than 100 million electron volts (blue indicates lowest, yellow highest).Credit: NASA/DOE/Fermi LAT Collaboration", "width": 1920, "height": 801, "pixels": 1537920 } }, { "id": 290272, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453309, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Fermi_novae_large_labels.jpg", "filename": "Fermi_novae_large_labels.jpg", "media_type": "Image", "alt_text": "These images show Fermi data centered on each of the four gamma-ray novae observed by the LAT. Colors indicate the number of detected gamma rays with energies greater than 100 million electron volts (blue indicates lowest, yellow highest).Credit: NASA/DOE/Fermi LAT Collaboration", "width": 4800, "height": 2003, "pixels": 9614400 } }, { "id": 290274, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453312, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Fermi_novae_small_labels_print.jpg", "filename": "Fermi_novae_small_labels_print.jpg", "media_type": "Image", "alt_text": "These images show Fermi data centered on each of the four gamma-ray novae observed by the LAT. Colors indicate the number of detected gamma rays with energies greater than 100 million electron volts (blue indicates lowest, yellow highest).Credit: NASA/DOE/Fermi LAT Collaboration", "width": 1024, "height": 427, "pixels": 437248 } }, { "id": 290275, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453311, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Fermi_novae_small_labels_web.png", "filename": "Fermi_novae_small_labels_web.png", "media_type": "Image", "alt_text": "These images show Fermi data centered on each of the four gamma-ray novae observed by the LAT. Colors indicate the number of detected gamma rays with energies greater than 100 million electron volts (blue indicates lowest, yellow highest).Credit: NASA/DOE/Fermi LAT Collaboration", "width": 320, "height": 133, "pixels": 42560 } } ], "extra_data": {} }, { "id": 340575, "url": "https://svs.gsfc.nasa.gov/11608/#media_group_340575", "widget": "Single image", "title": "", "caption": "", "description": "Same as above but without labels.

Credit: NASA/DOE/Fermi LAT Collaboration", "items": [ { "id": 290276, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453313, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Fermi_novae_large_no_labels.jpg", "filename": "Fermi_novae_large_no_labels.jpg", "media_type": "Image", "alt_text": "Same as above but without labels.Credit: NASA/DOE/Fermi LAT Collaboration", "width": 4800, "height": 2003, "pixels": 9614400 } }, { "id": 290277, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453314, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Fermi_novae_large_no_labels_searchweb.png", "filename": "Fermi_novae_large_no_labels_searchweb.png", "media_type": "Image", "alt_text": "Same as above but without labels.Credit: NASA/DOE/Fermi LAT Collaboration", "width": 320, "height": 180, "pixels": 57600 } }, { "id": 290278, "type": "media", "extra_data": null, "title": null, "caption": null, "instance": { "id": 453315, "url": "https://svs.gsfc.nasa.gov/vis/a010000/a011600/a011608/Fermi_novae_large_no_labels_web.png", "filename": "Fermi_novae_large_no_labels_web.png", "media_type": "Image", "alt_text": "Same as above but without labels.Credit: NASA/DOE/Fermi LAT Collaboration", "width": 320, "height": 133, "pixels": 42560 } } ], "extra_data": {} }, { "id": 340576, "url": "https://svs.gsfc.nasa.gov/11608/#media_group_340576", "widget": "Basic text", "title": "For More Information", "caption": "", "description": "See the following sources:\n\n* [http://www.nasa.gov/mission_pages/GLAST/news/shocking-nova.html](http://www.nasa.gov/mission_pages/GLAST/news/shocking-nova.html)\n* [http://www.nasa.gov/press/2014/july/nasas-fermi-space-telescope-reveals-new-source-of-gamma-rays/](http://www.nasa.gov/press/2014/july/nasas-fermi-space-telescope-reveals-new-source-of-gamma-rays/)", "items": [], "extra_data": {} } ], "studio": "gms", "funding_sources": [ "NASA Astrophysics" ], "credits": [ { "role": "Producer", "people": [ { "name": "Scott Wiessinger", "employer": "USRA" } ] }, { "role": "Science writer", "people": [ { "name": "Francis Reddy", "employer": "University of Maryland College Park" } ] }, { "role": "Graphics", "people": [ { "name": "Francis Reddy", "employer": "University of Maryland College Park" } ] }, { "role": "Illustrator", "people": [ { "name": "Scott Wiessinger", "employer": "KBR Wyle Services, LLC" } ] } ], "missions": [ "Fermi Gamma-ray Space Telescope" ], "series": [ "Astrophysics Stills" ], "tapes": [], "papers": [], "datasets": [], "nasa_science_categories": [ "Universe" ], "keywords": [ "Ast", "Astrophysics", "Binary Star", "Earth Science", "Fermi", "Gamma Ray", "HDTV", "Red Giant", "Space", "Spectral/Engineering", "Star" ], "recommended_pages": [], "related": [ { "id": 20393, "url": "https://svs.gsfc.nasa.gov/20393/", "page_type": "Animation", "title": "T Coronae Borealis Nova Animations", "description": "Located 3,000 light-years away, T Coronae Borealis — T CrB for short — contains two stars that orbit each other: a red giant nearing the end of its life and an Earth-sized stellar remnant known as a white dwarf. The dwarf’s intense gravity rounds up some of the gas flowing off of the red giant, forming a flattened cloud of gas around the dwarf — an accretion disk. Gas in the disk gradually works its way inward, eventually flowing onto the white dwarf nestled at its center. Credit: NASA's Goddard Space Flight Center Conceptual Image LabAlt text: Animation showing the T CrB system || T_CrB_NOVA_SHOT_1_4k_30fps_ProRes.00300_print.jpg (1024x576) [91.6 KB] || T_CrB_NOVA_SHOT_1_4k_30fps_h264.mp4 (3840x2160) [18.1 MB] || T_CrB_Nova_S1 [0 Item(s)] || T_CrB_NOVA_SHOT_1_4k_30fps_ProRes.webm (3840x2160) [4.5 MB] || T_CrB_NOVA_SHOT_1_4k_30fps_ProRes.mov (3840x2160) [984.5 MB] || ", "release_date": "2024-11-04T11:00:00-05:00", "update_date": "2024-10-25T13:54:22.811188-04:00", "main_image": { "id": 1103406, "url": "https://svs.gsfc.nasa.gov/vis/a020000/a020300/a020393/T_CrB_NOVA_SHOT_2_4k_30fps_ProRes.00330_print.jpg", "filename": "T_CrB_NOVA_SHOT_2_4k_30fps_ProRes.00330_print.jpg", "media_type": "Image", "alt_text": "After decades of steadily raining onto the white dwarf, a layer of gas has accumulated on the surface. At the base of this layer, where the pressure and temperature is highest, the gas reaches a critical point and begins to undergo hydrogen fusion — the process that produces energy in the centers of stars like our Sun. Once started, the reaction runs away across the dwarf, resulting in a thermonuclear blast on a scale the size of Earth. For a few days, this eruption brightens the system so much that it becomes visible from Earth with the unaided eye.Credit: NASA's Goddard Space Flight Center Conceptual Image LabAlt text: Animation showing T CrB erupt", "width": 1024, "height": 576, "pixels": 589824 } }, { "id": 20184, "url": "https://svs.gsfc.nasa.gov/20184/", "page_type": "Animation", "title": "Fermi Sees a Nova", "description": "NASA's Fermi Gamma-ray Space Telescope has detected gamma-rays from a nova for the first time. The finding stunned observers and theorists alike because it overturns a long-standing notion that novae explosions lack the power for such high-energy emissions. In March, Fermi's Large Area Telescope (LAT) detected gamma rays — the most energetic form of light - from the nova for 15 days. Scientists believe that the emission arose as a million-mile-per-hour shock wave raced from the site of the explosion. A nova is a sudden, short-lived brightening of an otherwise inconspicuous star. The outburst occurs when a white dwarf in a binary system erupts in an enormous thermonuclear explosion. \"In human terms, this was an immensely powerful eruption, equivalent to about 1,000 times the energy emitted by the sun every year,\" said Elizabeth Hays, a Fermi deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. \"But compared to other cosmic events Fermi sees, it was quite modest. We're amazed that Fermi detected it so strongly.\" More information here. || ", "release_date": "2010-08-12T00:00:00-04:00", "update_date": "2015-12-02T10:26:23-05:00", "main_image": { "id": 490806, "url": "https://svs.gsfc.nasa.gov/vis/a020000/a020100/a020184/NovaCyg093500952_print.jpg", "filename": "NovaCyg093500952_print.jpg", "media_type": "Image", "alt_text": "Watch V407 Cyg go nova! In this animation, gamma rays (magenta) arise when accelerated particles in the explosion's shock wave crash into the red giant's stellar wind.", "width": 1024, "height": 576, "pixels": 589824 } } ], "sources": [], "products": [], "newer_versions": [], "older_versions": [], "alternate_versions": [] }