Moon Dog

From Bob's Stuff

Thursday December 11- The Moon was full and really bright and I saw something I’ve never seen before (from Wikipedia): “A moon dog or moondog (scientific name paraselene, plural paraselenae, i.e. "beside the moon") is a relatively rare bright circular spot on a lunar halo caused by the refraction of moonlight by hexagonal-plate-shaped ice crystals in cirrus or cirrostratus clouds. Moondogs appear to the left and right of the moon approximately 22° away. They are exactly analogous to sun dogs, but are somewhat rarer because in order to be produced the moon must be bright and therefore full or nearly full. While a moondog may be brightly colored, the lunar halos they form in typically appear colorless to the naked eye because their light is not bright enough to activate the color photoreceptors in humans." Well the one I saw HAD color like a rainbow, and I tried to photograph it but it didn’t come out as bright as I could visually see it, but I got it! Just click on the image that I uploaded to get a better view. Like I mentioned last night in my journal this full Moon would be the brightest of the year.

Lives of Other Stars II

        I went on my evening walk and re-listened to “Live of Other Stars” Podcast. I was especially interested in Mass Loss of stars and one class of star, the Wolf-Rayet, have over 20 solar masses, are very hot, and their stellar winds exceed of 1000 MPH which eject a lot of matter giving it a high rate of Mass Loss. If you remember that large stars, with over five solar masses, Mass Loss plays an important role in determining if the star will become a Neutron star, a Black Hole, or even (some believe) a white dwarf. So there is more to this transition to a Neutron star, a Black Hole, or a white dwarf than I was led to believe. And it isn’t set in stone depending on just how massive a star is.

Lives of Other Stars

        I went for my evening walk re-listening to the lecture on “Lives of Other Stars”. Smaller stars with 0.26 solar masses, our Sun is one solar mass, use convection unlike larger star’s Radiative Transport , and mixes the hydrogen in their atmospheres like a lava lamp which causes these small stars to burn all their hydrogen efficiently into helium and are not hot enough to burn helium (what is called helium flash). Their life span can be over 100 billion years and bypasses the red giant stage and goes right to being a white dwarf with a helium core. Stars one and a half time larger than on solar mass also use convection and smoothly transitions to burn heavier elements. Stars with over five solar masses, depending on Mass Loss, go supernova turning into Neutron Stars or Black Holes. Depending on how large a star determines what elements the star eventually burns, the degenerate gas pressure which holds the core from collapsing, and what element ignites a supernova. Population three stars were the first stars to ever form, with over 250 solar masses, and used proton/proton chain reactions to fuse hydrogen into helium to form the first heavier elements. These stars had a life of a few million years and enriched the early universe with these first heavy elements so that smaller stars could form.

Nebulas

        I went for my evening walk and listened to astronomy lecture on Nebulas. A Nebula is interstellar dust consisting of hydrogen, helium, and other trace elements. Nebulas are formed by dying stars that blow out their atmospheres; from Red Giants or Supernovas. New stars are born in Nebulas. There are two kinds of nebula: reflecting and emission. A Reflecting Nebula reflects light from a nearby bright star, and its color is blue. An Emission Nebula is usually the process of new stars being born within and the light from these stars or protostars excites electrons in atoms of the Nebula to higher energies to emit photons. Emission Nebulas are red in color.

        My friend Kula called to ask about the Leonid Meteor Shower that peaks on the 17th and 18th of this month. I told her that the Moon would probably washout any meteors and the smoke from the fires would be another obstacle. I’m not going to bother with this one but I might go out to take a peak just in case!

Life Cycle of the Sun

        Went on my evening walk and listened to an astronomy lecture about the life cycle of our Sun. To make a long story short it will go through a few phases after it falls off the main sequence five billion years from now; burn most of its hydrogen fuel as its diameter expands to form a Red Giant. Helium replaces hydrogen in the core. Hydrogen still fuses a layer around the core as it condenses and heats up. At 100 million Kelvin helium starts to burn in the core producing carbon and oxygen. While all this is happening the outer layers are being breathed out forming a planetary nebula. When all the helium is turned into carbon, the core collapses down into a White Dwarf with electrons packed tightly together (what is called electron degeneracy). Basically a White Dwarf is a diamond and does not fuse matter but shines under its stored heat.

Orionid meteor Shower

        Last night at 3am before I went to bed I went back outside to view the Orionid meteor shower after an unsuccessful attempt at 10pm when I didn’t see a one. Orion was higher in the Northeast sky and I wasn’t let down! Even though the third quarter Moon was washing out the smaller meteors I saw many quickly shoot across the sky in bright white streaks, too cool!

More on Nucleosynthesis

        I went for my evening walk and listened to the astronomy lecture on “Nucleosynthesis”. They discussed the process of Stellar Nucleosynthesis where heavier elements are made by the proton-proton cycle that creates lighter elements in cool stars, and the carbon-nitrogen-oxygen cycle in stars that are larger than 1.4 solar masses. These larger stars burn and create elements all the way up to iron 57 that needs more energy than the star can produce to burn and there is no pressure holding up the stars core, and the star collapses (depending on its size) into a neutron star or a black hole. This is called Explosive Nucleosynthesis. The collapse takes less than a second and creates a tremendous amount of energy to bombard iron and other elements with neutrons to create heavier elements like gold, uranium, and the like. There is another Explosive process: one that involves an accretion disk that surrounds a white dwarf, a neutron star, or a black hole. In each case, it involves a binary system where the dwarf, a neutron star, or a black hole sucks matter from a neighboring large star, the disk reaches critical mass, and goes nova repeatedly. In addition, there is one other process where an old star that is rich in neutrons speeding from its core hit other atoms in the stars atmosphere to combine into heavier atoms. I’ll have to combine all that I have written so far on Nucleosynthesis and add to it later when I have time, but right or wrong; this is how I understand the process at this time. We are indeed made of star stuff!

Big Bang Nucleosynthesis

        Went for my evening walk listening again to “Nucleosynthesis”. It starts with the “Big Bang Nucleosynthesis” at ten billion degrees where high-speed collisions occur in a soup of Protons, Neutrons, and Electrons. A free Proton catches an Electron and becomes a Hydrogen atom. The Hydrogen atom fuses with another Hydrogen atom to form Deuterium with one Proton and one Neutron, and releases a Positron (antielectron-antimatter that is annihilated when it encounters and Electron, producing two high-energy Photons- Gamma Rays), and a Neutrino (an elementary particle that has little mass and doesn’t carry an electric charge). Then the Deuterium fuses into Helium-3, and two Helium-3 fuses into Helium-4 that is very stable. An increase in energy was released as heavier isotopes and elements were fused. In the first three minutes after the Big Bang most of the Deuterium was converted into Helium and small amounts of Lithium, and nothing heavier because things cooled down and the process stopped. I’ll listen to it again hopefully tomorrow and write about Stellar Nucleosynthesis.

Nucleosynthesis: Elements from Stars

        I went on my evening walk listening to a new astronomy lecture called “Nucleosynthesis: Elements from Stars”. Nucleosynthesis is the formation of elements from either the Big Bang (light elements no greater than Lithium); Stellar Nucleosynthesis (heavier elements from Carbon to Calcium); Explosive Nucleosynthesis (elements heavier than Iron) created by Supernova; and Cosmic Ray Spallation that creates lighter elements by bombardment of gas and dust in the interstellar medium. Some of this I already knew but the term for it “Nucleosynthesis” is new to me. There was so much discussed in the lecture, and for me to understand fully the process, I’ll have to listen to it again and add to this post later. I did catch one error though; they said that light takes over a hundred thousand years to reach the surface from the Sun’s core, when in fact it takes around thirty-three thousand years. I think they had gotten their data from an old NASA site that hasn’t corrected it to the new theory yet.

A little stargazing with binoculars

I went outside with my binoculars to do a little stargazing. Fat Cat was glad to have my company and sat on my lap wanting to be scratched. Found the Andromeda galaxy for the first time this year. The Pleiades cluster was rising out of the east. At this angle in the eastern sky, it looked to me like a silhouette of a person, maybe Lincoln. Cool!

Higgs Boson degeneracy?

        I got to thinking about the Higgs Boson and if it is what’s at the center of black holes- that all matter is compressed into these Higgs Bosons. I read that the Higgs Boson is what gives matter mass. A very large star would first implode to the electron degeneracy pressure which holds the core, and then collapse further to neutron degeneracy, and then finally to a singularity where the Higgs Boson degeneracy takes over. This is all speculation on my part and they haven’t even found the Higgs Boson yet.

The Inverse Square Law

        I was so tired from all that work that I just laid down for a little while and relaxed. Then I went for an early evening walk and listened to a questions and answers astrophysics lecture. One question I thought interesting was about the force of magnetism. Why is it that the Earth’s magnetic field can be over whelmed by small refrigerator magnets? The answer was that the magnetic force loses its power because of the inverse square law- it loses it strength inversely proportional to the square of the distance to the source. Therefore, you can take a small magnet and place it next to a compass, which over powers the Earth’s magnetic field. Then draw the small magnet away by several feet- it no longer affects the compass and the Earth’s magnetic field takes back over because it’s so prevailing- 4000 miles beneath our feet and still extends way out into the upper atmosphere and into space to reflect high-energy particles emitted from the Sun solar wind causing auroras and protecting life.

The Search for the Theory of Everything

        Went for my evening walk listening to a lecture about “The Search for the Theory of Everything” that is combining all the forces of physics into one grand theory. Basically, the present “Standard Theory” doesn’t include Gravity or is having a hard time getting it to fit into equations. The String Theory does include Gravity but there isn’t any proof that this theory is plausible yet, but it is the only one that is in the running at present and scientist are at an impasse hoping to fine some kind of verifiable evidence. One such support for String Theory may be the Large Hadron Collider, which just went online this September, if the collider could measure gravity at a microscopic scale and provide evidence of extra dimensions. Also, scientist are looking for the ever elusive Higgs Boson, which they believe exists and causes matter to have mass. At least this is how I understand it right now. There was so much covered that I’ll have to re-listen to it.

The Strong and Weak Nuclear Force

        Went for my evening walk listening to a lecture on “The Strong and Weak Nuclear Force”. The Strong Force is what holds the nuclei of atoms together. When larger nuclei, on the periodic table of over one hundred, form, the strong force begins to break down and isn’t strong enough to hold everything together. The strong force causes gluons to fly back and forth between protons and neutrons to hold them together in the nucleus of an atom. The electron is not affected because of the electrostatic force. The Weak Nuclear force has to do with decay of neutrons and the cause of radioactivity. I’ll just leave it at that for now and I’ll re-listen to it again since there was so much more in the lecture.

        Went for my evening walk listening to the lecture again on the “Strong and Weak Force” so I could get a little more info out of it. The Strong Force also extends (by way of Gluons) down into the realm of Quarks which protons and neutrons (Hadrons) are made of. A proton is made up of two “up” quarks with an electric charge of +2/3 and one “down” quark with an electric charge of -1/3, which add up to a +1 charge for the proton. A neutron is made up of one “up” and two “down” quarks and does not have a charge. A free neutron will over a short period of time decay into a proton, and electron, and an antineutrino. The Strong force at this small of a level acts upon the color (charge properties) of the quark. At least this is how I understood it.

Galaxies

        I went on my evening walk listening to a lecture on Galaxies. They discussed how most galaxies are conglomerations of smaller dwarf galaxies- our Milky Way is one of these that draw smaller ones into it. The Magellanic Clouds, which are irregular dwarf galaxies, pass by the Milky Way and some of the mass is being exchange by both galaxies by tidal forces. There are remnants of smaller dwarf galaxies that have been observed, which were absorbed billions of years ago by our Milky Way. Other super large galaxies had just started out that way from the beginning and not by way of cannibalizing smaller galaxies. There are other kinds of galaxies, which take on many shapes and forms: spirals, elliptical, and irregular and many sub categories. Seyfert galaxies have a very bright nucleus, are believed to contain a supper massive black hole that emits high-energy radio waves from debris from its accretion disk surrounding and falling into its black hole. Kind of like Quasars but less energetic. When two large galaxies have a collision the dust of both, combine to form many new large blue stars that die in a matter of a few million years and can eventually spell the death of the newly formed galaxy by forming heavier elements from hydrogen and lighter elements that are used in the creation of new stars.

Electromagnetism

        Last night I found a nice site for Astronomy Podcasts called Astronomy Cast and downloaded “Electromagnetism” lecture and listened to it while on my evening walk. They talked about the history of magnetism and the Electromagnetic Theory developed by Maxwell who tied light, magnetism, and electricity as being the same phenomena. The massless, chargeless Photon, I learned, is the intermediary of electromagnetic radiation in all wavelengths and at different energies. There was a little talk about Virtual Particles and magnetic fields, which I’ll have to investigate later. Also discussed were black holes with accretion disks; how electromagnetism causes flares that shoot off into space at its poles. The lecture was only thirty minutes and packed with lots of information.

Faster than light spacecraft

        I read an interesting article online about an idea for a faster than light spacecraft that could use dark energy to form a bubble around its self and decreases the dark energy in front of the ship to bring the expansion rate of the universe to a stop. It wouldn’t break the laws of Einstein: that nothing can travel faster than light in our universe. Because, they say, that the universe is expanding faster than light can travel and by using this expansion the spacecraft can exceed the speed of light. The only problem is that it would take the whole mass of Jupiter converted into pure energy to accomplish this! I don’t think we’ll see this for a long time to come. I wrote about something like this about black holes, that the compression of matter as it falls toward the singularity is squeezed to a point that it loses space time and could leak out of a black hole because it could exceed the speed of light- I’m only guessing on this part. Maybe this is dark matter or dark energy. Nobody knows yet what this dark energy/matter is.

Equation for Intelligent Life

        Went for my evening walk re-listening to the last astronomy lecture. It was about the different theories of the big bang and the universes that could have happened if it was weighted differently than the one we live in. Professor Bloom also discussed the prospects of intelligent life in other solar systems using astronomer Frank Drake’s famous equation N = R Fp Ne Fl Fi Fc L: (I copied the following from an online source)
N = the number of civilizations with whom we can connect
R = the rate of star formation (10 stars per year in our galaxy)
Fp = the fraction of stars that develop planets
Ne = planets suitable for life
Fl = planets that actually develop life
Fi = planets that develop life that is intelligent
Fc = civilizations that communicate
L = civilizations at the stage at which communication can occur
So you just plug in the numbers and depending on what numbers you use the results change in favor for or against intelligent life. Interesting!

Big Bang 3- Cosmology

        Got my new iPod hooked up and loaded with an astronomy lecture and went for my evening walk. The lecture was “black holes 3” and covered so much data that I’ll have to re-re-listen to it before I can write about it in any detail. It’s my second time listening to this lecture series from UC Berkeley. I only wished I had the talent and mental capacity to have gone there when I was younger! Anyways the lecture was about what happened ten to the minus forty-three seconds after the big bang, and we can only speculate what happened before that. Professor Joshua Bloom talked about Professor George Smoot of Berkeley who recently won a Nobel Prize for his discovery of the beginnings of structure in the early universe that was the catalyst to forming galaxies. Very interesting! He also talked more on dark energy.

Lecture Big Bang 2/ Albireo Binary Star System

      I went on my evening walk re-listening to an astronomy lecture “Big Bang 2” that covered a lot of stuff previously mentioned and went into the structure of the universe (as seen by a fourth dimensional person). Depending on the mass of the universe which is determined by Omega (that is the density of space and the shape of space). If omega is greater or lesser than one the universe will either expand forever or collapse– one type of universe is the Positive curvature like a balloon that is called a “closed universe” has an omega of more than one and will collapse into the “big crunch”- then a flat universe that is open, infinite with no boundaries and expands forever- finally a saddle-shaped one that is “open”, has an omega less than one, is infinite and unbounded and the universe will expand forever. It is presently believed that our universe has an omega of 1 and is flat. The Professor talked about black energy that makes up most of the known universe. There was a lot more! When I got back from my walk Fat Cat was waiting at the back gate for me!

      Read on someone’s astronomy blog that there is a nice binary star in Cygnus located at the Swan’s head called Albireo that has a yellow-white star and a blue one. I just had to get the telescope out to give it a look-see! The dang binary was at my zenith (straight up) and it was hard to get my telescope that is on a tripod to view it. I ended up putting it on a table and tilting it back on one leg to be able to observe this binary star system, but it was well worth it! Just as beautiful as Algieba in the constellation on Leo!

Big Bang 1- Cosmology

        Went for my evening walk re-listening to an astronomy lecture “Big Bang 1” About Cosmology: that looks at the universe as a whole, cosmological principal: that assumes that the laws of physics are the same throughout the universe, and space on a large scale is both Homogenous: matter is distributed uniformly throughout the universe, and Isotropic: there’s no preferred direction in space.

        Read an article the other day “Before the Big Bang; three theories explore the back-story of creation” in Discovery Magazine that Ron left me. I know the subject matter somewhat and didn’t find too much of anything that I didn’t already know. There was one about the Arrow of Time that delves into the direction of time, entropy and equilibrium, where the universe keeps expanding and get to a state of “low entropy” creating other “Big Bangs”, which I found interesting. Also there was another that states there is no such thing as time, only now. This idea of only “now” is something I wrote about before in my column: “Thought for the week: An instant in time is all we have to plan for the future and think of the past. Thought for the week: Time is an illusion."

Quasars And Hubble Constant/Law

        Got home and went on my evening walk re-listening to an astronomy lecture on Quasars (quasi stellar radio source). A quasar is a supermassive black hole with the output of one trillion Suns and lies in the center of galaxies with a very high redshift making it very far (billions of light years) away taking it almost to the beginning of the Big Bang, some 13.7 billion years ago. This gets into the expansion of the universe and where the Hubble Constant/Law of the expansion rate of 72 kilometers for each megaparsec begins to fail at these very large distances. Quasars are powered by an accretion disk formed around the black hole where mater spirals in creating energetic electromagnetic radiation from a small area that out shines the galaxy which it resides.

Meteors and Super Clusters

        Last night I had some friends over and we were outside and saw four or five meteors in the span of fifteen minutes! The Perseid meteor shower peaks on August 12th so I’m thinking that these may be a prelude to the shower. I had Andrew point out the stars and constellations to Stefanie that I taught him.
        Then tonight I went outside with my binoculars and sat down with Fat Cat in my lap while I observed Sagittarius and all the wonderful nebulas, globular clusters, and open clusters that were filling the night sky. I saw five more meteors stream across the sky coming from the SE!

        Went for my evening walk re-listening to an astronomy lecture on colliding galaxies, galaxy clusters, more on dark matter, and the Hubble’s law that the receding galaxies redshift is proportional to its distance and are speeding away at 72 kilometers a second per megaparsec. A parsec is 3.3 light years or 30 trillion kilometers, so a megaparsec is a long ways away! The Andromeda galaxy is .077 megaparsecs away and that is the closest galaxy to the Milky Way. Our Galaxy belongs to “The local group” that has around 36 galaxies with a diameter of 10 million light years. There are larger clusters, one the super cluster in Virgo has around 1300 or more galaxies and extends 2.2 megaparsecs out from its center, mighty big!

Tuesday, July 29, 2008

        Went for my evening walk re-listening to an astronomy lecture on galaxies and dark matter. There are different types of galaxies: Elliptical, Spiral, and irregular galaxies with odd shapes that don’t fall into the other two types. Dark matter makes up 90% of the mass in galaxies. No one really understands dark matter and what it consists of, but there are a few ideas floating around. First inferred by Fritz Zwicky of Cal Tech in 1933 when he was observing a galaxy cluster and compared their calculated mass with their motion about each other and found there was four hundred times more mass than should be. Zwicky also came up with the idea of neutron stars. I would like to read more about him!
        Read more of the Richard Feynman book until it was time to do my exercises. Did my stretches, lifted weights, and went for my nightly run. When I got back I took out my telescope to do a little star gazing. The night was clear but the atmosphere was a little unstable. Jupiter was bright in the sky and I watched it and its moons for a while. Two of its moons were very close to the planet and on opposite sides. I could barely make out the two bands of the planet tonight. Then I just did a sweep of Sagittarius looking at a few globular clusters and the rich star fields near the Tea Cup.

Lecture on Neutron Stars

        Went on my evening walk re-listening to an astronomy lecture on Neutron Stars. Neutron stars are formed in type 2 supernovas. During the process of a star’s death where it’s burning through different elements it finally reaches iron 56 which cannot fuse. This iron core builds up pressure to the Chandrasekhar limit and electron degeneracy pressure takes over. Different outer layers keep burning lighter elements until they reach iron 56, which falls into this core (which is the size of the Earth) to exceed this limit. When the Chandrasekhar limit of 1.4 solar masses is exceeded and the pressure of the electron degeneracy pressure can no longer hold up against gravity the core implodes very fast at .01 the speed of light (I think that is the speed he said) and compresses around two solar masses into a sphere ten miles in diameter. As this takes place electrons and protons are squeezed together forming neutrons and it is the neutron degeneracy pressure that takes over the fight against gravity. Neutron stars spin very fast because of the angular momentum it got as it collapse into a smaller area- like a skater pulling in her arms to spin faster. Neutron stars emit high-energy radiation because of the spin and electrons flowing on its surface between its two magnetic poles- like a lighthouse. These are called Pulsars. This was how neutron stars were first found thirty years after Fritz Zwicky anticipated their structure. The next lecture will be on black holes.

Lecture on Supernovas

        Went on my evening walk re-listening to another astronomy lecture about supernovas. There are many ways a star can go supernova but the lecture was on type 1A and type 2. A type 1A supernova is formed in a binary system where one star is a red giant and the other is a white dwarf. The white dwarf accretes matter from the red giant and if the white dwarf exceeds the Chandrasekhar limit of 1.4 solar masses it goes supernova- 5 million times brighter than the Sun. Type 2 is from massive stars with at least nine solar masses and releases so much energy that it out shines the galaxy they implode in. Heavier elements than iron are created in this process by electrons and protons that merge to create neutrons. If it wasn’t for type 2 novas we wouldn’t exist because there wouldn’t be any heavy elements heavier than Iron 56. Oh there is so much more on type 2s that I could write about, but time grows late.

Fate of Stars II

        Went for my evening walk and re-listened to “Fate of Stars II” about the processes that power stars. Hydrostatic equilibrium is where the outgoing thermal pressure is in balance with the gravity of incoming matter. This Hydrostatic equilibrium is caused by the fusion of four hydrogen atoms that overcome the Coulomb barrier (at high temperatures strips away electrons from the hydrogen atom leaving protons) that collide at high velocities forming a new helium atom. The energy left over after this process (a helium atom has less mass than four hydrogen atoms) is released in the form of neutrinos and high-energy photons. These photons eventually slow down as they make their way through to the stars surface and radiate into space. Our Sun converts hydrogen to helium at a rate of four million tons a second. After a star runs low on hydrogen (our Sun in about five billion years from now) will start fusing helium into carbon and oxygen and go off the main sequence of the HR diagram becoming a red giant. At this point blowing off its outer shells creating a nebula, and if it is below 1.4 solar masses, with a white dwarf at its center. Above 1.4 solar masses and depending on how massive the star is you can have a neutron star or a black hole (this will be discussed in the next lecture). The electron degeneracy pressure holds up a white dwarf core. Wow did I just write all this!
        Watched “Science Now” on PBS about Stem cells, filming underwater critters, SETI and the new Allen radio telescopes, and leaches used for modern medical purposes.
        I forgot to add that last night I setup my telescope (as I did tonight) to view Jupiter before the Moon came up. Well last night I believe I saw one of the moons go behind the planet: there was a little bump on Jupiter’s edge that slowly disappeared, cool! Tonight I saw four moons lined up.

The Fate of Stars 1

Went on my evening walk re-listening to another astronomy lecture on “The Fate of Stars”, about what happens to a star when it leaves the main sequence of the HR Diagram, and also emission and reflective nebulae: Young hot stars with temps of 13,900C excite the atoms and cause them to re-emit the UV light that they absorb when they cascade down to a lower energy state drive emission nebulas. Reflective nebulas, on the other hand, are particle clouds near a star with a temp less than 13,900C and the light is reflected. The emission nebulas are the most colorful.

Exoplanets

Went for my evening walk re-listening to another astronomy lecture on exoplanets or extra solar planets. At this time there are 307 that have been found. Most exoplanets have been discovered using the Radial Velocity or Doppler Method by studying spectral lines and looking for blue and red shifts as the star and its planets orbit around a common center of gravity called a barycenter that create a wobble- a stars blue shift is coming at us, and the red shift is going away. Astronomers need to use computers to sort this out because the shifts are so minuscule. Then Professor Bloom went on to discuss the formations of planets around protostars that form out of the gas and particles of nebulas. By loosing angular momentum these particles fall into the protostar by the effects of gravity that then creates a flat disk. These particles begin to heat, which causes pressure, and depending on the gasses makeup- heavier particles closer to the central mass and lighter particles in farther orbits and their closeness to the central mass determines when a cohesion process starts to bind them to one another. Astronomers have found these protoplanetary disks in other star systems. I think I got this right.

Spectrum and Blackbody Radiation

I re-listened to lecture three about spectrum and blackbody radiation. As I understand it a blackbody absorbs light- like a black surface is hotter than a white surface heated by the Sun. If you took the atmosphere away from the Sun it would be a perfect black body- this was where I got confused: why is something that radiates light a black body? Well maybe if we looked at the hot back surface heated by the Sun in infrared wavelengths we would see that it was radiating- as I’m writing this I think I just now understand why the sun would be a perfect black body without its atmosphere now! Okay this leads us to where we get into absorption lines- the Sun’s atmosphere has gasses whose electrons absorb energetic photons at certain wavelengths which create a dark line on the absorption spectrum. And we can use these dark lines to find what elements are present in a star.

July 01 2008

        Went outside with the binoculars when it got dark. I was looking to the western part of the sky when I eyed what I believed to be Mars. So I got out the telescope to check it out, and it was Mars (last time I saw Mars it was in the horns of Taurus). I also saw a beautiful binary system with an orange and yellow star, but I didn’t know what constellation it was in, so I took out my laptop and ran the astronomy program, and found it was Algieba about 126 light years away. Funny that I didn’t recognize Leo the constellation Algieba lies in, but my excuse is that Leo laid sideways in the western horizon. I also noticed that Saturn was nearby, had it sighted and focused when a faint satellite came zipping across my field of view. So I followed it till it vanished into the west. Cool! I didn’t realize at the time that I had been using a 6mm eyepiece so the satellite must have been very, very small. Maybe it was Ed White’s space glove he lost in his 1965 spacewalk! Nah! Well maybe!
        Got inside just in time to watch “Seeing in the Dark” by author Timothy Ferris. I’ve seen it before and really liked it, so I made it a point to see it again tonight. One item I missed last time was when he was talking about the Andromeda Galaxy being 2.5 million light years away. When we are viewing the whole galaxy, the light from the nearest edge gets to us one hundred thousand years before the light from the back does! Now that gave me pause to think of scale, and just how immense our universe is! And there are billions upon billions of these galaxies in every direction we look. Great show!

old cheap equatorial mount

        I got back home and went for my evening walk. It was too windy to listen to a lecture but I think I want to pause on the lectures until I learn as much as my little brain can absorb of the Spectra: the absorption and emission lines that the last two lectures talked about.

        Went outside to setup an old cheap equatorial mount I had lying around. I must have done something wrong somewhere and I think it was the polar alignment. I haven’t done this since college but that was on a more professional mount. This one’s RA and Dec setting circles are so small that it was hard for me to read. Anyways I was able to follow Jupiter using the fine adjustment cables, but not very well. I’ll have to go online later to find some documentation and see what I’m doing wrong. The seeing wasn’t very good with all the particulates suspended high in the air from the fires in northern California scattering light. It made the sky appear like a quarter Moon was out and I didn’t need a flashlight to navigate around. So I got out the binoculars and sat back trying to name some of the constellations I know. There was Hercules high overhead, Corona Borealis, Bootes, and several others. The asterism “Summer Triangle” with Vega (in Lyra), Deneb (in Cygnus), and Altair (in Aquila), was making its way up in the eastern sky. I used Kstars on the laptop to help me find some of the other constellations I’m not that familiar with. All in all it was a productive night and it feels good to get outside and try to recall the names of the constellations and stars.

Moved the 12" Telescop to the shop. Lecture 4

        Got home to take a short nap, then I went on my evening walk and listen to lecture four of the astronomy class. More about absorption lines: wrote about that yesterday, emission lines: when energetic electrons radiate energy to seek a lower orbit, and emissions nebulae: where the clouds of dusty interstellar gas, or the remains of dying stars, are ionized with ultraviolet radiation by hot stars nearby. Oh there’s so much more! But I think I got a little bit of an understanding of it now in my tiny brain. I’ll need to study this more because it seems to be very important and I want to make sure I get it down pat.
        Decided to move the Big 12” Telescope out of the battery room and into the new shop where I’ll have easy access to it. The sky was a little hazy but not as bad as the last few nights. I set it all up, collimated the focus, and then trained it on Scorpio and its stars. The brightest in the constellation is Antares whose size is 700 times greater than the Sun. Played around in that area of the sky for a few hours.

Spectra and Electron Orbits

Went for my evening walk listening to the rest of lesson 3. It was about how electrons in orbit around a nucleus get excited by photons and change orbits depending on how much energy the photon carries. Depending on which frequency the photon and orbit of the electron determines what frequency the electron can accept and the orbit the electron will jump to. The spectra of a star can help in finding out the star’s makeup, if it is moving towards or away from the observer, and if it is a binary system it can tell the mass of the two stars and their period. I’ll have to delve more into this!