Shasta Astronomy Club Newsletter

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1 Astronomers just mapped the inside of a supernova It turns out these events could be even more impressive than we thought. By Megan Ray Nichols A supernova is the largest explosion you might ever see if you ever get to see it! It s the death of a star, and stars go out with a bang. They re still mostly a mystery to science. It s possible to understand the basic processes behind them, but predicting them accurately or getting a solid understanding of the chemistry has proven difficult. The Death of Stars Although here on Earth we live in a single-star system, binary star systems are common. (With another 70 times its mass, Jupiter could have been the second star in our system. Instead, it became a planet.) In a binary star system, one star often reaches the end of its life first. Instead of exploding, smaller stars like our Sun will puff up into red giants and then shed their outer layers. Eventually, the core shrinks back down and condenses into a white dwarf. Even smaller stars skip the red giant phase and burn directly down to white dwarfs. A white dwarf has a significant gravitational pull. As its We ve taken the first steps toward that goal though. Thanks to improvements in technology, computer models have been able to replicate what exactly happened in SN 1987A: a supernova that occurred 30 years ago. The hope is that by better understanding supernovae, we can learn about the creation of the stars and planets that fill the universe and, therefore, the development of life. What is a Supernova? If you are lucky enough to see a supernova, it probably occurred in a different galaxy. The Milky Way has plenty, but they re much harder to see here thanks to the dust, gas, and other astronomical objects blocking our view. They re still the brightest, most exhilarating explosions that occur in our galaxy. A single supernova can appear brighter than the galaxy it resides in for a period of time, making it the brightest object in the sky. After the initial explosion, the remnant that you can see is the explosion of debris from the star. There are two ways for a star to reach this point, but both occur at the end of its lifetime. Star Star Party Location: Oak Parking Lot. Lot

2 companion goes through its own red giant phase, some of the material it sheds can be pulled onto the white dwarf. As more mass gets sucked onto the white dwarf, its equilibrium gets thrown off, and it will eventually explode, creating a supernova. This is only one of two ways that supernovae form, at least that we are aware of. For the largest stars, there is no red giant or white dwarf stage. Instead, the stars simply burn through all of their available hydrogen and are no longer able to use fusion to remain stable. This causes the inner core to collapse, and the still active matter on the outer shell of the star falls into the center, then rebounds in a supernova. Either way, a supernova spells death for a star. Mapping Death While we think we have a good understanding of how supernovae form, we don t have a good grasp of what happens inside them. This is mainly due to the fact that we ve never been able to observe one from the inside, or even up close which is good; you do not want to be inside one because you d be dead. What we do know is that the largest explosions in the known universe put physics in some weird predicaments. They pop out new elements that make up everything else, including you and me. When you hear someone say that you re made of star stuff, they aren t making that up. The deaths of stars have given us every naturally occurring element in creation. So it s understandable that astronomers want to find out what happens. How were scientists able to map this supernova, exactly? Astronomers have continued to observe the changes in a supernova observed in 1987, called SN 1987A, located in the Large Magellanic Cloud. SN 1987A is an optimal candidate to study since it s not yet strongly affected by its surroundings. data. If its electronics weren t protected, signals could cross and prevent discoveries. The array depends on all 66 antennas and accompanying electronics synchronizing down to a millionth of a millionth of a second. No pressure! Because the telescopes work together at short submillimeter wavelengths, they are able to create the highestresolution images. The inner core of SN 1987A previously eluded astronomers because gas and dust blocked out other methods of observation. ALMA s ability to see these fine details helped astronomers finally see past the obstructions. Then, they created 3-D maps of the elements and molecules found within the collapsed supernova with the data collected. In the last 30 years, SN 1987A had time to cool down and start forming new molecules. Now we have the first results of what kinds of elements form as the result of one of these explosions. So, what did astronomers find? Scientists observed the formation of numerous elements, including carbon, nitrogen, and oxygen, as well as more complex molecules. These were carbon monoxide, silicon monoxide, and formylium. This leads to a whole new way to understand the physics and chemistry of supernovae. Since molecules and elements were created during this supernova, scientists may have to reevaluate their expectations for the stars. These explosions might be capable of more than we thought. Recently, a team from the University of Virginia used the Atacama Large Millimeter/submillimeter Array (ALMA) to study the supernova. ALMA is an array of radio telescopes designed to work together as an interferometer to process information. Astronomers chose ALMA because of its ability to see in submillimeter wavelengths. However, ALMA is susceptible to radio frequency interference. It is imperative that scientists block out all background interference since radio frequency devices are particularly susceptible to a wider variety of noise that can skew Star Party Location: Parking Lot

3 New Horizons next target might be a binary pair Ground observations of the New Horizons spacecraft s next target last month revealed the distant object, lurking in the outer Solar System more than four billion miles from Earth, might have an unconventional elongated shape, or even consist of two icy bodies orbiting one another in an age-old cosmic dance. The New Horizons team deployed 24 mobile telescopes to Chubut and Santa Cruz provinces in Argentina to catch the tiny world, officially named 2014 MU69, briefly blotting out light from a star. Called an occultation, the event helped scientists learn more about the robotic mission s next target, including its size, shape, orbit and the environment around it. Two years after making the first close-up encounter with Pluto, NASA s plutonium-powered New Horizons probe is speeding toward a flyby of 2014 MU69 on Jan. 1, A handful of detections from last month s field campaign in Argentina improved scientists understanding of 2014 MU69 s shape. Researchers said the object could be a extreme prolate spheroid akin to a skinny football or a binary pair in which two bodies might be gravitationally locked close Star Party Location: Parking Lot.

4 together, or even touching, according to NASA. This new finding is simply spectacular, said Alan Stern, principal investigator on the New Horizons mission from the Southwest Research Institute in Boulder, Colorado. The shape of MU69 is truly provocative, and could mean another first for New Horizons going to a binary object in the Kuiper Belt. I could not be happier with the occultation results, which promise a scientific bonanza for the flyby. Scientists have set an upper limit on the likely size of MU69 at 20 miles (30 kilometres) long. If there are Orbiting in the faraway Kuiper Belt, MU69 will become the most distant object ever visited by a spacecraft when New Horizons zips by on New Year s Day NASA officials expect to give the target a new name before New Horizons makes its flyby at a relative velocity of more than 9 miles per second (14 kilometres per second). Miniature worlds like 2014 MU69 are likely the leftover ice and rock fragments that formed larger objects like Pluto, the moons of some Uranus and Neptune, and other dwarf planets in the outer solar system. The Kuiper Belt is a ring of ancient icy remnants from the earliest part of the solar system s 4.6 billion-year history circling the sun beyond the orbit of Neptune. Its population includes continentsized words like Pluto and the even-farther dwarf planet Eris, and perhaps hundreds of thousands of objects the size of 2014 MU69 or larger. Observations by Hubble and the European Space Agency s Gaia mission pinpointed MU69 s orbit, telling scientists when the object would pass in front of stars, casting shadows on Earth s surface. Watching MU69 s passage between Earth and a distant star was a chance to learn more about the object than astronomers could ascertain from conventional observations. The tiny world appears as a fuzzy dot of light even through Hubble. An occultation visible June 3 from Argentina and South Africa was the first chance to study MU69 s shape and size. Scientists boarded NASA s flying infrared astronomy observatory, called SOFIA, for a similar July 10 opportunity to search for debris around MU69 that could pose a hazard to New Horizons. MU69 blocked a brighter star July 17, giving scientists their best view of the object s shape. While data are still being analysed, scientists probably will not know MU69 s true shape until New Horizons is on final approach in December 2018, Stern wrote in an to Spaceflight Now. These exciting and puzzling results have already been key for our mission planning, but also add to the mysteries surrounding this target leading into the New Horizons encounter with MU69, now less than 17 months away, said Marc Buie, the New Horizons co-investigator who led the observation campaign. A search by the Hubble Space Telescope discovered MU69 in 2014 after other surveys turned up no suitable targets for New Horizons following its encounter with Pluto on July 14, A series of thruster firings steered New Horizons on a new course for MU69 soon after the Pluto flyby. Star Party Location: Parking Lot

5 Sunday Monday Tuesday Wednesdy Thursday Friday Saturday Veteran s Home Star Party Great American Eclipse 8:30am Boat Ramp Parking Lot Star Party 26 Club Breakfast 8am Humble Joe s The Shasta Club is always looking for articles, photos and suggestions from our readers. If you have a story to tell about your adventures in amateur astronomy or a quick tip that needs to be shared, go ahead and send it to us at the following address Greg95111@gmail.com Articles can be in MS Word, Rich Text, PDF, or Plain Text. We can also cut and paste directly from an . Photos can be in JPG, PNG, PSD, GIF or various other graphic formats. Note, due to copyright issues we can only accept original photos. Star Party Location: Parking Lot.