Category Archives: Astronomy

Horizon Event: The big EHT reveal

The Event Horizon Telescope team announces its major discovery following two intense and quiet years of data analysis on top of a longer period of development.   A nice testament to aperture synthesis and international collaboration as the rest of the world spirals into madness.  Damn!!!

Youtube Channel: National Science Foundation

Context for the interested public:
Youtube Channel: Sixty Symbols

 

Where are they now?: Carol Meier on Voyagers 1 and 2

Narrator Carol Meier has a meticulously researched, splendidly detailed, and wonderfully delivered update on the twin Voyager spacecraft and their epic journey of discovery from Pasadena to the outskirts of the solar system.  It isn’t clear if this is a commissioned piece or one she did on spec.  It is engrossing either way.

Youtube Channel: Carol Meier

Calling the shot: Brian Metzger on kilonovae

Soon after LIGO‘s first detection of a black hole-black hole merger, the astronomical community was hinting about a potentially more scientifically  exciting event within the interferometer’s grasp: The merging of two neutron stars. When two dark objects coalesce, the product is unsurprisingly dark. Colliding neutron stars on the other hand might emit light of some kind and the collision product need not necessarily be a black hole. More intriguingly, so-called kilonovae resulting from neutron star collisions have been proposed as the actual origin in our universe of many elements heavier than iron, challenging the conventional wisdom of these coming from supernovae.

Here’s a prescient talk by Prof. Brian Metzger of Columbia University and coiner of the term ‘kilonova’ on the consequences of neutron star binary mergers. He discusses their signatures in the gravitational wave record and across the electromagnetic spectrum to their ultimate role in nuclear synthesis. Given at Harvard on 16 March 2017, it is quite accessible for a technical colloquium presentation. A mere five months later on 17 August 2017, LIGO and its European counterpart VIRGO indeed detected the merger of two neutron stars and set of a flurry of observational activity across the globe and in space which confirmed at least qualitatively the predictions by Metzger and his group.

The details are still confusing.  For example, we can assume that it takes a long time for two neutron stars to form, presumably from the death as a supernova of each of a large, but not too large, binary pair.  These violent events will eject a lot of material into the interstellar medium.  The neutron stars then spiral slowly and combine, releasing a lot of neutrons to stick to light elements, transmuting them up the periodic table through the r-process.  But, where do these light elements come from if the ejecta from each of the progenitor stars has had a very long time to spread? (*)

Harvard’s Edo Berger has a concise summary of the multimessenger gold rush incited by the event in a special issue of Astrophysical Journal Letters.  Many of the papers are free to download.  As an aside, I was acquainted with Edo when he was an undergraduate physics student at UCLA while I was a researcher in the same department.  I had no idea then he’d become one of the Dukes of Earl of  high energy astrophysics.

(*) Addendum 20 April 2019: After a year of futility in not finding an answer to this question, I emailed Prof. Metzger and asked.  In a prompt and gracious reply he said that the ejecta from the merging neutron stars create the seed nuclei required for the r-process.  There are sufficient protons (10-30%) in the ejecta to form nuclei of mass number ~100 within milliseconds.  These then absorb further neutrons within the constraints of beta decay to create very heavy elements within a few seconds.  So,  it seems that neutron stars aren’t neutrons all the way down!

30 May 2020: New video source; prior channel was deleted.

Youtube Channel: CfA Colloquium

 

Youtube Channel: Kowch737

 

Space Music: Paul Novros accompanies the universe

The documentaries below were made in the 1970s by Lester Novros, then a professor at the USC film school where his students included George Lucas.  The understated elegance of these films is nicely framed by Paul Novros‘s music.  The younger Novros is a professor of jazz at CalArts.  I asked him whether he had any soundtracks available.  He was pleasantly surprised to be reminded of the work but has no separate recordings or scores.

Lester Novros and his Graphic Films studio had a major albeit little-known influence on Stanley Kubrick and 2001: A Space Odyssey. Special effects legend Douglas Trumbull worked with him in Los Angeles but ultimately moved to work directly with Kubrick in England. Barbara Miller’s article “Graphic Films and the Inception of 2001: A Space Odyssey” is good reading.

via the U.S. National Archives Youtube Channel

via the Department of Defense channel at the Internet Archive

via the National Archives and Records Administration at the Internet Archive

(links to videos 2 and 3 updated 3/22/19 following the deletion of Jeff Quitney’s Youtube Channel)

Voyager – The Interstellar Mission

39 years ago today, Voyager 1 took flight on its Grand Tour. It has gone farther than any other man-made object in history and won’t stop until it reaches the stars long after we and all that’s important to us are dust. Idealism wasn’t for chumps back then. Or maybe it was. JPL and NASA post the mission data from all these interplanetary missions and it is all free.

Filmmaker Santiago Menghini brings an artist’s perspective to the journey in his short film, “Voyagers.”

via aeon.co

International Office Hours: Chris Impey takes your questions

Astronomy buffs should enjoy Chris Impey’s free online courses offered through Udemy and Coursera. One interesting feature of the Astronomy State of the Art course is his regular online office hour where he takes questions submitted in real time as well as by email. The questions are invariably very good, spanning terrestrial, planetary, galactic, and cosmological topics. Impey takes time to respond thoroughly. The live sessions are broadcast on a Google Hangout and archived on Youtube. Here’s a collection of them.

So near, yet so far: Carnegie Observatories 2016 Lecture Series

Update: 17 March 2016
The seminar series including music performances will be webcast live this year. Details will be provided in the next few days
LectureSeries2016SmallAnnoc

Image courtesy of the Carnegie Observatories

The Carnegie Observatories of Pasadena have announced their 2016 Lecture series, beginning in early April 2016 at the Huntington Library in San Marino.   There will be four talks by learn’d astronomers on the Las Campanas observatories, Planet formation, Exoplanets, and the lifecycle of Galaxies.  Each will be preceded by music performances by students from the Colburn School.  The talks are free but reservations are required.  Doors open at 6:45pm, talks begin at 7:30pm.

Visit the Observatories’s Youtube Channel for rigorous yet accessible talks from previous years.  The only downside is that the events are on Monday nights,  a hell of a schlep for those of us in the South Bay.

Carnegie Spring Lectures at the Huntington Library
1151 Oxford Road, San Marino
All Lectures are in Rothenberg Auditorium.

Monday, April 4th 2016
Las Campanas Observatory: A Southern Window on the Universe
Dr. Mark Phillips
Director, Las Campanas Observatory, Associate Director for Magellan
Carnegie Institution for Science

Monday, April 18th 2016
A Short History of Planet Formation
Dr. Anat Shahar
Staff Scientist, Geophysical Laboratory
Carnegie Institution for Science

Monday, May 2nd 2016
Exoplanets
Dr. Kevin Schlaufman
Assistant Professor of Physics and Astronomy, Johns Hopkins University
Carnegie-Princeton Fellow

Carnegie Observatories & Princeton University

Monday, May 16th 2016
The Secret Lives of Galaxies
Dr. Katherine Alatalo
Hubble Fellow,
Carnegie Observatories