Star Stryder

Archive for the 'Stars' Category


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BAA / AAVSO Day 2: Novae & Supernovae for all

The word Novae generally refers to a “New Star,” or a “Guest Star” - An object that springs up in the sky quite suddenly as a new but non-permanent object. Today we give these non permanent sky features a dozen or more names: Supernovae (types I & II with all sorts of extra letters), Recurrent […]

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AAVSO/BAA Day 1: Binary Adventures

Variable stars come in many forms - there are happy little regular stars, widely separated and merrily circling ones dancing an eon long dance. Some white dwarfs - dead stars, cooling into stellar embers of stars - become vampires as they gravitationally suck mass from their companion and heat themselves back out of the stellar […]

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AAVSO/BAA Day 1: Paula and Pulsating White Dwarfs

After several days of travel, I’ve settled into the front row of the BAA/AAVSO meeting in New Hall, in Cambridge, UK. Dr. Paula Skody is giving an excellent talk on pro-am collaboration to make Hubble Space Telescope observations of cataclysmic variables. She studies pulsating white dwarfs - stars whose outer 99% have oscillations that […]

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Star Formation in the Center of the Galaxy

I saw a really cool paper (to me) on the pre-print server today. Astronomers Kuzic et al. have made detailed measurements of two groups objects in the center of the galaxy within half a parsec of the center of the Milky Way. These objects, named IRS 13E and IRS 13N (aren’t those exciting names?) are […]

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Tau Boo Back Flips (magnetically)

As some of you may know, my favorite favorite star to bring up when discussing binaries is Tau Boo B (Go ahead, say it out loud. Giggle. Join me in the giggling. Wasn’t that fun?). This little red dwarf star is the companion star to the much more famous, but no where near as fun […]

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Cepheid + Light Echo = Accurate Distances

I am so so frustrated that I can’t get the full journal article associated with this press release. I’m going to have to do some emailing tomorrow to see if someone can get it to me.
Here is what has me excited. In a new paper in Astronomy and Astrophysics (which my Uni doesn’t get) with […]

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4 stars within 6 AU

The universe keeps throwing neat stuff up for our telescopes to look at. A team lead by Evgenya Shkolnik (University of Hawaii), has observed a tight system of 4 stars crammed within 6 AU of one another - If located in our solar system, all four stars would fit within the orbit of Jupiter! The […]

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Type 1a Supernoave: A Non-Standard Candle

One of the most exciting discoveries of astronomy in recent years was the measurement of an acceleration term in the universe’s rate of expansion. Announced by both the Supernova Cosmology Project at the Lawrence Berkeley National Laboratory and the High-z Supernova Search Team, these results at once confirmed one another an revolutionized how astronomers view […]

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Giants and Dwarfs with Barium

I’m beginning to think that a large fraction of the astronomical community is in pre-semester stars chaos. The number of press releases has radically slowed, and the journal articles just don’t seem to be flying as fast and furious as normal. Admittedly, this is a personal impression, and while I have data to support the […]

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The Sun and its Danger Zone: The Chromosphere

One of the deeply confusing aspects of our Sun (and other stars) is their temperature structure. Starting in the core, the Sun is millions of degrees kelvin and supports nuclear burning. As you leave the nuclear burning core and climb first into the radiative zone and then the convective zone, the temperature systematically drops until it reaches a temperature of several 1000 degrees at a star’s surface. This makes sense. In the core, the gas is being compressed under the pressure of all the upper layers of the star gravitationally pushing down. The pressure allows nuclear reactions to release energy in a form that can heat things up: specifically light. That light then interacts with stellar material, being absorbed and reabsorbed over and over as it loses energy and goes on a random walk through the radiative region (think light bulb heating the air around it), and then (think of the lava lamp material above a light bulb) it also gives off energy as it heats cells of material at the base of the convective zone that rise and convectively give off heat as the cells rise (and then, when cool, sink back down).

So far so good.

The problem is, as you then move away from the surface of the Sun, you enter regions where the temperatures again go up - A lot - like back to millions of degrees hot levels of a lot!

And no one fully knows why. This is a very counter intuitive situation. Imagine that the surface of a lava lamp was 23C and the air half an inch away was 200C! In a press conference Wednesday, astronomers announced that they think they may have found a starting point for understanding what is going on in this bizarre situation.

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