The Galactic Starburst Region NGC 3603

Shooting for an April first post date! I just started researching and hooboy, I am going to go way way way way down the rabbit hole of tangents. I think everything is interesting and cool.

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.)

Glossary:

cosmic microwave background radiation—the electromagnetic radiation left over from the time of recombination in Big Bang cosmology.

cosmology—the study of the properties of our universe as a whole.

heliacal rising—when a star or constellation rises at the same time or just before the sun.

parapegma—a list of star rising times.

retrograde—the apparent motion of a planet in a direction opposite to that of other bodies within its system, as observed from a particular vantage point.

sidereal year—the time required for the earth to complete an orbit of the sun relative to the stars.

star catalog—an astronomical catalog that lists stars.

star chart/map—A star chart or star map is a map of the night sky. Astronomers divide these into grids to use them more easily. They are used to identify and locate astronomical objects such as stars, constellations, and galaxies.

tropical year—the interval at which seasons repeat and the basis for the calendar year.

Wilkinson Microwave Anisotropy Probe—a spacecraft operating from 2001 to 2010 which measured temperature differences in the cosmic microwave background radiation leftover from the Big Bang. (I said ‘anistropy’ in the podcast, whoops)

Script/Transcript (It’s not exactly what I said, but it’s what I was going off of. It’s conversational and it’s less rambly than what I actually said)

Sources:

Cosmic microwave background radiation info

More Big Bang info

Timeline of the Big Bang

Babylonian constellation/zodiac list

Babylonian star catalog

Retrograde motion

Evans, James. The History and Practice of Ancient Astronomy. Oxford UP: New York, 1998.

...and class notes from a class on Ancient Astronomy I took with Prof. James Evans.

My argument for using Wikipedia is that it is shockingly accurate when it comes to ancient material. I’m going to try to stick to academic and government sources though.

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

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

I saw the picture and I thought it was a photo of the space between a Venetian blind and a window frame but no. No. It was a moon between the rings of Saturn.

The Orion Nebula

via reddit

It’s way too late for this, but it’s important to note that NASA didn’t discover the new earth-like planets. It was a group of astronomers lead by a dude name Michaël Gillon from the University of Liège in Belgium. Giving NASA credit for this gives the United States credit for something they didn’t do, and we already have a problem with making things about ourselves so. just like…be mindful. I’d be pissed if I discovered a small solar system and credit was wrongfully given to someone else.

Peak Perseid mornings: August 11, 12, 13 | EarthSky.org

When is the peak of the Perseid meteor shower in 2020? The greatest number of meteors is most likely to fall in the predawn hours on August 12, yet under the light of a wide waning crescent moon.

Where to look, and when.

Ep. 23 Quasars and Blazars - HD and the Void

Hear an overview of two of the major types of active galaxies: quasars and blazars! I discuss the history of the study of quasars as well as where we're going with future studies of these extragalactic objects.

When I was in Ireland in 2013, I kept seeing signs for ‘quasar.’ I finally learned that it’s the European way of saying laser tag. It has nothing to do with quasars, which are a specific type of a specific type of galaxy. Listen to this week’s (pretty short) podcast on two types of active galaxies: quasars and blazars.

Below the cut, I have the transcript, sources, music credits, and timeline of people I talked about! If you have suggestions for topics I could cover, please send me a Tumblr message or tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me. Please subscribe on iTunes, rate my podcast and maybe review it, and tell friends if you think they’d like to hear it!

(My thoughts on the next episode are the SOFIA observatory, Chuck Yaeger, or the great Stephen Hawking. The next episode will go up April 2nd.)

Glossary

active galaxy or active galactic nucleus- a galaxy with a small core of emission embedded at the center. This core is typically very variable and very bright compared to the rest of the galaxy. These galaxies emit much more energy than they should; this excess energy is found in the infrared, radio, UV, and X-ray regions of the electromagnetic spectrum.

blazar - a subcategory of active galaxy, it is an extremely bright, distant object, powered by a black hole, which emits massive amounts of energy. It is distinct from a quasar because it is even brighter.

extragalactic objects - objects outside our Milky Way galaxy.

interferometry - a group of techniques to extract information from superimposing electromagnetic waves to create interference. In radio astronomy, this is done by using a wide spread of receivers to look at the same distant object, then bringing that data together with a correlator that can create a larger, clearer picture than an individual radio telescope alone could.

lunar occultations - when stars pass behind the Moon. This is the basis for a method of determining and mapping star positions.

quasar - a subcategory of active galaxy, it is an extremely bright, distant object, powered by a black hole, which emits massive amounts of energy. It is distinct from a blazar because it is less-bright. The name is a contraction of “quasi-stellar radio source” (which is not necessarily true of all quasars—90% are radio-quiet).

torus - a donut shape.

Script/Transcript

Timeline

Walter Baade, German (1893-1960)

Rudolph Minkowski, German-American (1895-1976)

Fritz Zwicky, Swiss (1898-1974)

Gordon Stanley, New Zealander (1921-2001)

John Bolton, English-Australian (1922-1993)

Owen Bruce Slee, Australian (1924-2016)

Allan Rex Sandage, American (1926-2010)

Cyril Hazard, English (1928- )

Maartin Schmidt, Dutch (1929- )

Hong-Yee Chiu, American (1932- )

Stephen Hawking, English (1942 -2018)

Jedidah Isler

Sources

Active Galaxies via NASA (Dec 2016)

Galaxy shapes via Cornell University (April 2000)

Galaxies and Black Holes by David Merritt, published on NED by Caltech and NASA

Cyril Hazard via University of Pittsburgh

The Discovery of Quasars and its Aftermath via Journal of Astronomical History and Heritage (2014)

“Characteristically, Fritz Zwicky (1898–1974; Figure 11) immediately pointed out that ‘All of the five quasi-stellar galaxies described individually by Sandage (1965) evidently belong to the subclass of compact galaxies with pure emission spectra previously discovered and described by the present writer. (Zwicky, 1965: 1293).’ A few years later, Zwicky was less circumspect and wrote: ‘In spite of all these facts being known to him in 1964, Sandage attempted one of the most astounding feats of plagiarism by announcing the existence of a major new component of the Universe: the quasi-stellar galaxies ... Sandage‘s earthshaking discovery consisted in nothing more than renaming compact galaxies, calling them ‘interlopers‘ and quasistellar galaxies, thus playing the interloper himself. (Zwicky and Zwicky, 1971: xix)’”

Lunar occultations via Sky and Telescope

Quasars and Blazars by Matthew Whiting (a chapter in his thesis, What made the quasar blush? Emission mechanisms in optically-red quasars) via the Australia Telescope National Facility (2000)

Jedidah Isler on quasars and blazars via TED Talks (March 2015)

Quasar definition via Space.com (Feb 2018)

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

Filler Music: ‘Into The White’ by Pixies off their album Wave of Mutilation.

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

What is an upcoming project/mission you're most excited for?

It is likely that I’ll be assigned a mission to the International Space Station (ISS) within the next few years.  We’ve had a continuous presence on the Space Station for 17 years now, along with our international partners (Russian Space Agency, European Space Agency, Japanese Space Agency, and Canadian Space Agency).  Missions on the ISS typically last 6 months.  I’m incredibly excited to contribute to the impressive array of scientific experiments that we are conducting every day on ISS (I am a scientist after all!), and very much look forward to the potential of going for a spacewalk and gaining that perspective of gazing down on the fragile blue ball that is our home from above.  Beyond that, being part of test missions on the Orion spacecraft (currently under construction at NASA!) would be an extraordinary opportunity.  The current NASA plan is to send astronauts in Orion in a mission that will go 40,000 miles beyond the Moon in the early 2020s, reaching a distance further than that ever travelled by humans.  I’d certainly be game for that! 

Five Famous Pulsars from the Past 50 Years

Early astronomers faced an obstacle: their technology. These great minds only had access to telescopes that revealed celestial bodies shining in visible light. Later, with the development of new detectors, scientists opened their eyes to other types of light like radio waves and X-rays. They realized cosmic objects look very different when viewed in these additional wavelengths. Pulsars — rapidly spinning stellar corpses that appear to pulse at us — are a perfect example.

The first pulsar was observed 50 years ago on August 6, 1967, using radio waves, but since then we have studied them in nearly all wavelengths of light, including X-rays and gamma rays.

Typical Pulsar

Most pulsars form when a star — between 8 and 20 times the mass of our sun — runs out of fuel and its core collapses into a super dense and compact object: a neutron star. 

These neutron stars are about the size of a city and can rotate slowly or quite quickly, spinning anywhere from once every few hours to hundreds of times per second. As they whirl, they emit beams of light that appear to blink at us from space.

First Pulsar

One day five decades ago, a graduate student at the University of Cambridge, England, named Jocelyn Bell was poring over the data from her radio telescope - 120 meters of paper recordings.

Image Credit: Sumit Sijher

She noticed some unusual markings, which she called “scruff,” indicating a mysterious object (simulated above) that flashed without fail every 1.33730 seconds. This was the very first pulsar discovered, known today as PSR B1919+21.

Best Known Pulsar

Before long, we realized pulsars were far more complicated than first meets the eye — they produce many kinds of light, not only radio waves. Take our galaxy’s Crab Nebula, just 6,500 light years away and somewhat of a local celebrity. It formed after a supernova explosion, which crushed the parent star’s core into a neutron star. 

The resulting pulsar, nestled inside the nebula that resulted from the supernova explosion, is among the most well-studied objects in our cosmos. It’s pictured above in X-ray light, but it shines across almost the entire electromagnetic spectrum, from radio waves to gamma rays.

Brightest Gamma-ray Pulsar

Speaking of gamma rays, in 2015 our Fermi Gamma-ray Space Telescope discovered the first pulsar beyond our own galaxy capable of producing such high-energy emissions. 

Located in the Tarantula Nebula 163,000 light-years away, PSR J0540-6919 gleams nearly 20 times brighter in gamma-rays than the pulsar embedded in the Crab Nebula.

Dual Personality Pulsar

No two pulsars are exactly alike, and in 2013 an especially fast-spinning one had an identity crisis. A fleet of orbiting X-ray telescopes, including our Swift and Chandra observatories, caught IGR J18245-2452 as it alternated between generating X-rays and radio waves. 

Scientists suspect these radical changes could be due to the rise and fall of gas streaming onto the pulsar from its companion star.

Transformer Pulsar

This just goes to show that pulsars are easily influenced by their surroundings. That same year, our Fermi Gamma Ray Space Telescope uncovered another pulsar, PSR J1023+0038, in the act of a major transformation — also under the influence of its nearby companion star. 

The radio beacon disappeared and the pulsar brightened fivefold in gamma rays, as if someone had flipped a switch to increase the energy of the system. 

NICER Mission

Our Neutron star Interior Composition Explorer (NICER) mission, launched this past June, will study pulsars like those above using X-ray measurements.

With NICER’s help, scientists will be able to gaze even deeper into the cores of these dense and mysterious entities.

For more information about NICER, visit https://www.nasa.gov/nicer

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

This is an article from last year, but still very exciting news! I wonder how far it’s progressed since?

Voyager 1's thrusters fired up for first time since 1980

NASA scientists are able to fire up a set of thrusters on Voyager 1 for the first time since 1980, allowing the spacecraft to orient itself in interstellar space, 13 billion miles from Earth.

The venerable Voyager 1 spacecraft.  Still impressing after all these years.