Julie: York Universe’s Expansion

Show notes for Episode 189, March 17th 2014
Hosts: Paul, Julie, Hugh
Title: Julie: YorkUniverse`s Expansion!

Introducing Julie Tome: words from Julie about her background from York U to Science North to the OSC and the ROM.

This week in space/astronomy history:
1. March 16, 1750  Birth of Caroline Herschel, sister of William Herschel and astronomer in her own right. She discovered several comets including the periodic comet 35P/Herschel-Rigollet. She received many awards for her contributions to science.
2. March 13, 1781 William Herschel discovered Uranus.  Uranus came from Greek mythology and the God of the Sky (Ouranos).  Observed constantly in earlier times (eg Flamsteed catalogued Uranus in 1690 as 34 Tauri), Herschel tried naming the new planet (thought to be a comet initially) Georgium Sidus (after King George III) but following Bode’s suggestion, Uranius became the aame of choice universally from 1850.
3. Vanguard 1 launched March 17 1958 (56 years in space!).  First solar powered satellite (4th launched) and oldest satellite to still be in orbit.  Last contact in May 1964.  1.5 kg in mass, 16.5 cm diameter sphere, the primary mission was to collect geodetic data (Earth shape) and to measure atmospheric drag (eccentric orbit of 133 minutes).

News:
1. Big announcement from Harvard-Smithsonian centre for astrophysics, BICEP2 found B-mode polarization in the CMB which is a smoking gun for gravitational waves caused by the rapid inflation of the universe immediately following the big bang. The major point of it is that this is the first ever direct observation of gravitational waves: B-mode fluctuations (polarized light that swirls and curls around itself) are predicted to result from gravitational waves caused by rapid inflation of the universe, and BICEP2 (Background Imaging of Cosmic Extragalactic Polarization) has for the first time detected those exact B-mode fluctuations. The challenge in identifying these fluctuations is that they are incredibly faint, and that your data may be skewed by E-mode fluctuations that have been distorted by gravitational lensing to look like B-mode fluctuations. The takeaway message is this: if the observations are confirmed then gravitational waves predicted by inflation have been discovered, which in turn lends immense credibility to the theory of inflation, explains why spacetime is flat and implies that our universe is in fact infinite and always will be infinite. The next question: what drove inflation? Suggested reading: Space.com article High level summary from Bad Astronomer http://bicepkeck.org/
2. New Hypergiant star 1300x Sun diameter.  The stats for the star are impressive indeed: dubbed HR 5171 A, the binary system weighs in at a combined 39 solar masses, has a radius of over 1,300 times that of our Sun, and is a million times as luminous. Located 3,600 parsecs or over 11,700 light years distant, the star is 50% larger than the famous red giant Betelgeuse. Binary star (about 10 AU apart) but surfaces only 2.9 AU!  1300 day orbital period for this contact eclipsing binary.  Amateurs and professional astronomers combined to unravel this system dating back over 60 years.
Read more: http://www.universetoday.com/110205/astronomers-identify-the-largest-yellow-hypergiant-star-known/#ixzz2wGoaPuna (Suggested Reading: Universe Today article, ESO Press Release, arXiv preprint)
3. Contest via NASA to find potentially harmful NEO. NASA and Planetary Resources (the asteroid miners!) have conspired with topcoder.com a crowd sourced algorithm development platform, to identify potentially harmful asteroids from data sets consisting of 4 images seperated by about 10 minutes each. The winning algorithm will be able to correctly identify errors and artifacts in the data and will receive $35,000 in prize money, so if you think you have what it takes then head on over to topcoder and give it a shot! (Suggested Reading: IFLS article, Contest Details)
4. Mars Reconnaissance Orbiter went into safe mode March 9 after an unexpected switch from one main computer to another. NASA scientists are working on the problem and hope to have the spacecraft back online in a few days. This happens somewhat regularly, this is the 5th time in MRO’s lifetime, the last time was November 2011. MRO is the link between Opportunity and Curiosity rovers and Earth. Mars Odyssey can handle the science operations while MRO is being repaired.
(Suggested Reading: Space.com article)  Curiosity Rover tweeted March 13 that MRO is back online. (Suggested Reading: JPL press release)
5. The IAU has released a statement against the practice of organizations letting members of the public name features on Mars (and other places) for a fee. The statement is not explicit about which organization they are criticizing but the target would appear to be Uwingu. The Uwingu team  “consists of nationally and internationally accomplished scientists, educators, NASA vets, and business people, who are passionate about astronomy, space exploration, and space education.” It uses its naming projects to raise money to fund science and education. (Suggested reading Space.com article, Uwingu web site)
6. Yutu Rover: The little jade rabbit that could survives its third lunar night, to enter its fourth lunar day! Given that it was designed to be a 3 month mission that means that as of March 14th the little Jade bunny has met its mission design requirements. Its instruments are for the most part still working, although it’s not able to maneuver its solar panels nor is it able to move around on the surface, but I’m happy to hear that it has survived! As an interesting side note, it’s always interesting to me the sense of personal and emotional attachment you end up feeling towards these little rovers as we follow along with their lonely journeys across other worlds (perhaps its the effect of watching WALL-E too many times!).
7. COSMOS episode last night: Episode 2. The big element to me last night was the discussion and explanation of Natural and Artificial Selection.  I thought this was done very well. Agreed, I also particularly liked the segment on how our eyes aren’t well adapted to life on land, we often forget that evolution is a bit of a one way street (hence, compound eyes!). We could possibly talk about Titan?
8. Arecibo observatory is back in action following a 6.4 magnitude Earthquake on January 13th this year that damaged one of the cables which moves the hanging detector around the area above the dish. I for one am glad to hear this not only because the Arecibo observatory has historically and presumably will continue to produce some great science (first evidence for neutron stars in 69, first binary pulsar in 74, first millisecond pulsar in 82, first extra solar planet in 94), but I am also glad to hear this because I think the Arecibo observatory is just one of the coolest telescopes out there. Our viewers will recognize it as the large 300m concrete dish in Puerto Rico that is used for radio astronomy and was featured in the films Goldeneye and Contact (along with many others I’m sure). The cable that was damaged was one of 18 cables that holds up the 900 ton focal platform, and interestingly this cable was already known to be a structural weak point: during the original construction of the facility one of the cables that was delivered was too short, so it was spliced together with another section of cable in order to span the appropriate distance–this structural weakpoint was exposed when the earthquake caused the cable to break.

Major Topics Discussed:

Topic: Where stars transition to Brown Dwarfs on the HR diagram
The Hertzsprung-Russell (HR) diagram Main Sequence (MS) has a lower temperature limit.  New observations by Dieterich & Henry suggest that the lower temperature limit of the MS (core hydrogen burning) appears to be around 2075K.  They examined 62 objects with spectral types M6V to L4, determining their temperatures and distances (and thus their luminosities) to plot the lower end of the MS.
When stars reach the MS they are in thermal equilibrium (hydrostatic equilibrium having been established by coire H fusion).  Brown Dwarfs however never reach such a stage as they are continually cooling.  Low mass, cool stars on the MS can be potentially very old whereas the Brown Dwarfs are relatively young.  Further, lower mass stars have lower radii whereas higher mass Brown Dwarfs have smaller radii (as they are held up by electron degeneracy rather than radiation pressure).
Suggested Reading: NOAO newsletter

Thanks for listening!
-YorkUniverse Team
__________
YorkUniverse is a co-production of Astronomy.FM and the York University Astronomical Observatory. For more information on us, check out the following links:
webpage: www.yorkuniverse.com
twitter: @YorkUniverse
AFM page: astronomy.fm/yorkuniverse
Observatory webpage: www.yorkobservatory.com
Observatory twitter: @YorkObservatory

Planets Near and Far

Show notes for Episode 187, March 5th, 2014
Hosts: Paul, Jesse
Title: Planets Near and Far

Surprisingly, it took Paul upwards of 55 min before he mentioned the southern hemisphere. Though it was probably Jesse’s fault as he brought up the Large Magellanic Cloud.

This week in space/astronomy history:
1. March 5th, 1979 – Voyager 1 makes its closest approach to the planet Jupiter at 349 000 kilometers (roughly the Moon-Earth distance). It began photographing Jupiter in January 1979, and finished in April 1979, however most of the discoveries were made in the week centred on the closest approach. A short list of discoveries made my Voyager 1: Jovian cloud vortex and movements, Jovian lightning and Aurora, the Jovian ring system, Io’s volcanism, Ganymede’s tectonic activity, Europa’s surface features, impact craters on Callisto. Voyager 2 followed on July 9th, 1979.
2. March 6th, 2009 – The Kepler Space Telescope is launched from Cape Canaveral en route to an Earth-trailing heliocentric orbit.

News:
1. The 715 new planets of Kepler. On Wednesday February 26th, 2014, NASA released the latest from the, now defunct, Kepler Space Telescope. They have found 715 new planets around 305 different stars. About 95% of these planets are smaller than Neptune, and 100 or so are roughly Earth sized. Most interesting, four of these planets are less than 2.5x the size of Earth and orbit in their star’s habitable zone. The data presented in this new crop represents data taken from May 2009 to March 2011 and is specific to multi-planet systems. With these new planets, the total known is now over 1700. (Suggested Reading: Bad Astronomer Article. NASA Press Release, Science @ NASA article, Universe Today Article).
2. Moon occults Lambda Gemini
3. A preliminary report out regarding Astronaut Luca Parmitano’s space suit malfunction. The report indicates that Mission Control did not send the endangered Astronaut back to the airlock in a prompt enough fashion. Parmitano warned the controllers multiple times that the water accumulating in his suit was not a result of the drinking bag (the expected issue at the time). The report also indicates that drinking bags don’t leak as often as originally cited. In fact, the report says there has never been a case of a drinking bag leaking during space walk. Parmitano was sent back to the airlock 23 min after he first indicated a problem, and he was sent back alone. Further, station push for science may have made the astronauts overlook a possible leak (found in the suite on a previous space walk). (Suggested Reading: Universe Today article, Luca Parmitano Wiki, NASA termination note).
4. NASA offering free Space Systems Engineering courses. Today was the first day of a free Space Systems Engineering course offered online by NASA and the Saylor foundation. The course will run for 6 weeks and aims to give the public an understanding of the systems engineering challenges that NASA scientists and engineers do battle with every day. The course is going to culminate in a final project to design a sample return mission to Mars, the student who produces the best project will win a trip to go and see the Goddard flight centre. Anyone who is interested in how NASA projects work should sign up for the course. Today (March 5th) was the first day so you won’t be too far behind. After completion of the course, you will be able to explain the value and purpose of systems engineering, the systems engineering project life cycle, and relate the roles of systems engineers in complex space missions. You will also identify the roles and concepts of operations, requirements, and trade studies in the project lifecycle and demonstrate the ability to apply these concepts to a real NASA mission. (Suggested Reading: http://www.saylor.org/sse101/, syllabus).
5. Mapping the Large Magellanic Cloud in 3D.
distance 163000 lightyears
key rung on cosmic distance ladder
used hubble to measure actual 3D rotation of the LMC in space
all about measuring stellar motions
relatively easy to get rotation, one side of galaxy is moving away, other is moving towards
however proper motions are harder to measure, you actually have to WAIT for the stars to move measured average proper motion of 6790 over 7 years, in 22 different fields, with quasars able to measure change in position at resolution of 0.03 milliarcsecond (60 000 000 times smaller than the full moon). equivalent to watching an astronauts hair grow 5cm over the course of a year on the moon combine this with the doppler rotation to get fully 3D view
awesome because the proper motions lead to indications of interaction with SMC and MW
NOTE: Hipparcus and Gaia
(Suggested Reading: Sky and Telescope article)

Major Topics Discussed:

1. Population III stars
Population III star SMSS J031300.36-670839.3, or SM0313 for short  found using the 1.35 metre SkyMapper telescope in Australia. This object some 6,000 light years from our Sun has the lowest metal abundance yet detected. It seems to be the result of an early universe low energy 60 solar mass supernova blast that expelled the outer atmosphere of its envelop while trapping most of its synthesised heavy elements in its black hole core. The implication is that the early universe may not have been as dominated by hypernova as originally suspected.
Keller et al suggest that apart from H and He, only 4 other elements exist in this tsar (Ca, Mg, Li, C).  There is 15 million times less Fe in SMSS than in our Sun! The actual age of this star remains to be determined but is suspected to be of order 13 billion years old.
S. C. Keller et al. “A single low-energy, iron-poor supernova as the source of metals in the star SMSS J 031300.36-670839.3” Nature, 2014

Thanks for listening!
-YorkUniverse Team
__________
YorkUniverse is a co-production of Astronomy.FM and the York University Astronomical Observatory. For more information on us, check out the following links:
webpage: www.yorkuniverse.com
twitter: @YorkUniverse
AFM page: astronomy.fm/yorkuniverse
Observatory webpage: www.yorkobservatory.com
Observatory twitter: @YorkObservatory

Meteors, Mars and Beyond (to Tatooine!)

Show notes for episode 185, February 10, 2014
Hosts: Paul, Hugh
Title: Meteors, Mars and beyond (to Tantooine!)

From the far flung visions of Galileo and Jules Verne, stopping off briefly to check up on Curiosity (and the latest “hole” on Mars), we finished the show by discussing the exciting research about circumbinary stars and the ability for exoplanets to survive amidst such ravaging gravitational influences.

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Burping Betelgeuse and Cosmic Ray: May 7, 2013

Show Notes: May 7th, 2013 UTC

Hosts:  Ryan, Paul, Jesse
Title: Burping Betelgeuse and Cosmic Ray

Podcast to Come! Show notes are below.

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NEOSSat and a Fireball Splat: Feb 26, 2013

Show Notes: February 26th, 2013 (GMT)

Title: NEOSSat and a fireball splat
Hosts: Jesse, Ryan

Ryan (@AstroInAction) and Jesse (@jesserogerson) were live-to-air! YorkUniverse took last monday 18 February 2013 off because of Family Day in Ontario Canada. Many great topics covered this week including a look at This Week in Space/Astronomy History, the publication of the newyorkuniverse.com website (thanks to @liannemanzer), The Canadian Space Agency‘s new satellite NEOSSat, and of course the meteor that airburst over Chelyabinsk, Russia on the 15th of Feb 2013.

That and much more in the show notes below. Thanks for listening all. Feel free to contact us through our website or twitter (@YorkUniverse).


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