Margaret Hamilton is A Computer Scientist And Mathematician. She Was The Lead Software Engineer For

The Meaning of Color in Hubble Images: An interactive slideshow that illustrates how the Hubble Space Telescope incorporates light in multiple wavelengths to produce it’s stunning imagery.

Astronaut tweets

Ep. 18 Zombie Stars and Supernovae - HD and the Void

Zombie stars were in the news in November but get in the holiday spirit by hearing about them now! Learn about the life cycle of a star, the power of a supernova, and what undeath looks like in a star.

In November, a couple lovely people brought my attention to articles about a recent discovery that headlines consistently referred to as the ‘zombie star.’ What the heck is a zombie star? What makes it a zombie? I found a zombie star from 2014 in addition to the one in 2017 and I dug into the life cycle of the average star to get a sense of what undeath looks like in stars.

Below the cut are my sources, music credits, a vocab list, and the transcript of this episode. Suggest what you think I should research next by messaging me here, tweeting at me at @HDandtheVoid, or asking me to my face if you know me. Please subscribe on iTunes, rate it and maybe review it, and tell friends if you think they’d like to hear it! Also, welcome if you found me through PodCon!

(My thoughts on the next episode are the International Space Station, the transit of Venus, or astronaut training practices. The next episode will allegedly be up on New Year’s Day, January 1st. We’ll see about that.)

Glossary

Chandrasekhar limit - the upper limit for the mass of an astronomical body that can support extreme density without imploding: about 1.4 times the mass of our Sun. Any white dwarf star that has less than that mass will stay a white dwarf forever; any star that exceeds the Chandrasekhar limit will end in a supernova. 

dwarf nova - a close binary system of a red dwarf, a white dwarf, and an accretion disk around the white dwarf. They brighten by 2 to 6 magnitudes depending on the stability of the disk, which loses material to the white dwarf. Categorized as a cataclysmic variable.

neutron star - a type of star that has gone supernova, when the surviving core is 1.5 to 3 solar masses and contracts into a small, very dense, very fast-spinning star.

nova - a close binary system of a white dwarf and a secondary star that’s a little cooler than the Sun. The system brightens 7 to 16 magnitudes in 1 to 100 days, and then the star fades slowly to the initial brightness over a period of several years or decades. At maximum brightness, it’s similar to an A or F giant star. Recurrent novae are similar to this category of variable but have several outbursts during their recorded history. Categorized as a cataclysmic variable.

pulsar - a type of neutron star that spins very, very fast. Also a kind of variable star that emits light pulses usually between 0.0014 seconds and 8.5 seconds. 

reflection telescope - reflects light rays off the concave surface of a parabolic mirror to get an image of a distant object. Higher contrast image, worse color quality. 

spectroscopy - the study of light from an incandescent source (or, more recently, electromagnetic radiation and other radiative energy) that has its wavelength dispersed by a prism or other spectroscopic device that can disperse an object’s wavelength. The spectra of distant astronomical objects like the Sun, stars, or nebulae are patterns of absorption lines that correspond to elements that these objects are made up of.

supernova - a massive star that explodes with a magnitude increase of 20 or more. Supernovae have led us to realize that the expansion of the Universe is accelerating.

supernova progenitors - the kinds of stars and conditions that will result in certain types of supernovae.

white dwarf star - a star that has exhausted all of its nuclear fuel (i.e. no longer has hydrogen to convert into helium through nuclear fusion). It is the hot, dense core of a star. Unless it is acquiring/accreting matter from a nearby star, it will cool over time and become a dead star.

Script/Transcript

Sources

Chandrasekhar limit via PBS, Jan 2012

“The Chandrasekhar Limit is therefore not just as upper limit to the maximum mass of an ideal white dwarf, but also a threshold. A star surpassing this threshold no longer hoards its precious cargo of heavy elements. Instead, it delivers them to the universe at large in a supernova that marks its own death but makes it possible for living beings to exist.”

Type I and Type II supernovae via Space.com

Type Ia supernovae via Swinburne University of Technology

Type Ia Supernova Progenitors via Swinburne University of Technology

Zombie star via NASA, Aug 2014

Curtis McCully “I was very surprised to see anything at the location of the supernova. We expected the progenitor system would be too faint to see, like in previous searches for normal Type Ia supernova progenitors. It is exciting when nature surprises us.” 

The abstract of the article McCully and his team wrote on Type 1ax supernovae via Nature Magazine, Aug 2014

Zombie star via CNN, Nov 2017

Arcavi: "My first thought was that this must be some nearby star in our galaxy, just varying its brightness. But when we got the first spectrum of it, we saw that it was in fact a supernova 500 million light-years away. My mind was blown. The fact that it got bright and dim five times was very unusual. We'd never seen a supernova do that before."

Arcavi: "This means that we still have a lot to learn about how massive stars evolve and how they explode." 

Robert Evans via Sky and Telescope, Sept 2005

2017 zombie star articles I didn’t use because there were too many of them:

Air and Space Magazine, Nov 2017

The Atlantic, Nov 2017

BBC News, Nov 2017

BGR, Nov 2017

Carnegie Science, Nov 2017

Earth Sky, Nov 2017

Express UK, Nov 2017

The Guardian, Nov 2017

Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity

Filler Music: 'Toll Free’ by the Shook Twins off their album What We Do

Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught

Spacewalkers Successfully Connect Adapter for Commercial Crew Vehicles

ISS - Expedition 50 Mission patch / EVA - Extra Vehicular Activities patch. March 30, 2017 Expedition 50 Commander Shane Kimbrough and Flight Engineer Peggy Whitson of NASA concluded their spacewalk at 2:33 p.m. EDT. During the spacewalk, which lasted just over seven hours, the two astronauts successfully reconnected cables and electrical connections on the Pressurized Mating Adapter-3. PMA-3 will provide the pressurized interface between the station and the second of two international docking adapters to be delivered to the complex to support the dockings of U.S. commercial crew spacecraft in the future.

Image above: Spacewalkers Shane Kimbrough (spacesuit with red stripe on legs) and Peggy Whitson are pictured shortly after exiting the Quest airlock this morning. Image Credits: @Thom_Astro. The duo were also tasked with installing four thermal protection shields on the Tranquility module of the International Space Station. The shields were required to cover the port where the PMA-3 was removed earlier in the week and robotically installed on the Harmony module. During the spacewalk, one of the shields was inadvertently lost. The loss posed no immediate danger to the astronauts and Kimbrough and Whitson went on to successfully install the remaining shields on the common berthing mechanism port. A team from the Mission Control Center at NASA’s Johnson Space Center in Houston devised a plan for the astronauts to finish covering the port with the PMA-3 cover Whitson removed earlier in the day. The plan worked, and the cover was successfully installed, providing thermal protection and micrometeoroid and orbital debris cover for the port. To round out the spacewalk, Kimbrough and Whitson also installed a different shield around the base of the PMA-3 adapter for micrometeoroid protection. The shield was nicknamed a cummerbund as it fits around the adapter similar to a tuxedo’s cummerbund worn around the waist.

Image above: Astronaut Peggy Whitson signs her autograph near an Expedition 50 mission patch attached to the inside the International Space Station. Image Credit: NASA. Having completed her eighth spacewalk, Whitson now holds the record for the most spacewalks and accumulated time spacewalking by a female astronaut. Spacewalkers have now spent a total of 1,243 hours and 42 minutes outside the station during 199 spacewalks in support of assembly and maintenance of the orbiting laboratory. Related links: International docking adapters: https://www.nasa.gov/feature/meet-the-international-docking-adapter Peggy Whitson spacewalk record: https://blogs.nasa.gov/spacestation/2017/03/29/astronaut-peggy-whitson-set-to-break-spacewalk-record-thursday/ Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html Images (mentioned), Text, Credits: NASA/Mark Garcia. Best regards, Orbiter.ch Full article

Spaceprob.es

Ep. 30 Coriolis Effect - HD and the Void

The Coriolis force is a force in physics that has profound impact on us here on Earth. Listen to hear how this apparent force has influence over the weather, tides, and even some creatures. I refuse to talk about the formulas surrounding it but I ...

We’re back in 2019 with an episode that would have been more appropriate to release during hurricane season: a discussion of the Coriolis force! This force was observed centuries ago but takes its name from the scientist who first considered it in terms of theory and physics. It has an impact on a vast range of natural phenomena, from weather patterns to ocean waves to the flights of flies and moths.

Below the cut are the glossary, transcript, a timeline of the people I mention, sources, and music credits. Send me any topic suggestions via Tumblr message (you don’t need an account to do this, just submit as anonymous). You can also tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me in real life. Subscribe on iTunes to get the new episodes of my so-far-monthly-updated podcast, and please please please rate and review it. Go ahead and tell friends if you think they’d like to hear it, too!

(My thoughts on the next episode are Stephen Hawking, Hedy Lamarr, or famous comets. The next episode will go up in late February.)

Glossary

Coriolis force - a force in a rotating system that acts perpendicular to the direction of motion and to the axis of rotation. On Earth, this tends to deflect moving objects to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

Ekman transport - the net motion of fluid that results from the balance between Coriolis and turbulent drag forces.

Eötvös effect - the change in perceived gravitational force that results from eastbound or westbound movement on Earth’s surface.

Kelvin waves - an ocean wave that is trapped at the Earth’s equator and along vertical boundaries like coastlines. They move towards the equator when they have a western boundary; towards the poles when they have an eastern boundary; and make a whirlpool when they have a closed boundary, moving counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Lagrange points -  five points where three bodies can orbit each other, yet stay in the same position relative to each other in a stable configuration. L1-L3 are in line with each other, while L4 and L5 are at the points of equilateral triangles in the configuration.

prograde - when a planet spins from east to west.

Rossby number - used to determine the relative importance of the centrifugal and Coriolis forces in maps of weather patterns. A small Rossby number indicates that a weather system is strongly affected by Coriolis forces, while a large Rossby number signifies that a system is affected by inertial and centrifugal forces.

Transcript

Timeline

Giovanni Battista Riccioli, Italian (1598-1671)

Francesco Maria Grimaldi, Italian (1618-63)

Joseph-Louis Lagrange, French (1736-1813)

Gaspard-Gustave de Coriolis, French (1792-1843)

Sir William Thompson, AKA Lord Kelvin, Scots-Irish (1824-1907)

Baron Loránd Eötvös de Vásárosnamény, Hungarian (1848-1919)

Ottokar Tumlirz, Austrian (1856-1928)

Fridtjof Nansen, Norwegian (1861-1930)

Vagn Walfrid Ekman, Swedish (1874-1954)

Carl-Gustaf Arvid Rossby, Swedish-born American (1898-1957)

Sources

Coriolis Effect via the University of Oregon

Coriolis Force via Wikipedia

Coriolis effect, two centuries before Coriolis via Physics Today (Aug 2011)

Gaspard-Gustave de Coriolis via Wikipedia

Coriolis effect via National Geographic

Hurricane, cyclone, typhoon, tornado – what’s the difference? via African Reporter (Sep 2017)

Wang, B. Kelvin Waves. University of Hawaii: Honolulu, 2002.

Ocean in Motion: Ekman Transport Background via NASA

Ekman transport via Wikipedia

What is a Geodesist? via Environmental Science

“The Second Coming” by W. B. Yeats via Poetry Foundation

Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity

Filler Music: ‘Ambergris’ by Tipper off their EP Fathoms

Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught

How does a microgravity garden grow when there’s no up or down? An advanced chamber, about the size of a mini-fridge, is giving us a clearer perspective of plant growth habits. Without gravity and the addition of a wide variety of light and humidity settings, the plants cultivated on the International Space Station provide a world of opportunity to study space-based agricultural cycles.

Learn more about our space garden HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

The Milky Way rising over Badlands National Park Keith Duvall

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One more reblog! Seriously, hit me up by Friday, April 14th if you have strong opinions about what I delve into next, research-wise. I’m ready to get back to it. You can tweet me (@HDandtheVoid) or comment here on tumblr maybe? I have anonymous on, no worries. :)

Ep. 1 MUL.APIN - HD and the Void

Welcome to the first episode of HD and the Void, space edition! Start at the beginning of the universe with the Big Bang, then zoom to the beginning of records of humanity's astronomical observations with the Mesopotamian star chart MUL.APIN. Bonu...

The first episode is here! I have never done this before and right now, I’m planning to put up a podcast every two weeks.

Below the cut is some elaboration on the episode itself, including my sources, music credits, a glossary, and a transcript (not an exact record of this episode, but it’s the script I was working with and it’s both conversational and also a little less rambling than what I actually said). I’m on Twitter now, too: @HDandtheVoid. I don’t know what I’ll put there yet except maybe fun little facts and, of course, notifications on when an episode goes up.

Let me know what you think of this episode, let me know what you think I should research next*, tell me a fun space fact… anything’s helpful at this point!

*(Move fast if you feel strongly about what I research next, though, cuz I have to get it done by April 24th—I don’t mention it in the podcast but this is me telling you now so I am held accountable; April 24th is the next podcast.)

Keep reading

Today I learned that the Curiosity sang itself ‘Happy Birthday’ on its year anniversary of being on Mars.

All alone.

Hundreds of thousands of miles from anyone or anything.

Guys I am depressed over robots now.