cosmic christmas lights

globular clusters are collections of thousands of stars, gravitationally bound together. a popular cluster visible with the naked eye is the pleiades cluster. the stars in a cluster orbit around the center of the cluster, just as the planets in our solar system orbit around the sun. it takes the stars a lot longer to move one time around their system though.... about 100,000 years! during our short human lives, it is very difficult to detect the motion of individual stars around a cluster!

a different method for studying the stars in a globular cluster, is to look at how the light levels of individual stars change... which occur for some stars on much shorter timescales. that brings me to the fascinating time-lapse movie of the globular cluster, M3 (NGC 5272), shown below.


cool, huh?! listen to whatever music you want, and its sort of like the popular choreographed christmas light displays!!

the movie above was created from 4 images taken within the same night! most of the stars remain the same brightness and color, but many stars change their brightness level drastically and become more blue over over this very short time period! these variable stars are called RR Lyrae stars (named after the first one identified - the RR star in the constellation Lyra).

these stars are different than our sun and the other stars in the image because they get larger and smaller over the course of a couple days. they inflate and deflate like a balloon, over and over, because of the specific nuclear reactions happening in their cores. changing the size of a star changes its surface area and temperature, and therefore how much light it produces and how bright it appears to our eyes. the RR Lyrae appears brightest when it is smallest in size and hottest is temperature.

once you identify RR Lyrae stars, you can use their changing brightness to accurately determine how far away they are!

thanks to julianne at cosmic variance who reminded me of this great image while she described the boost of funding the Large Synoptic Survey Telescope just received from Charles Simonyi and Bill Gates!!

what does the sun know?

link

Comet 8P/Tuttle

here's a beautiful composite image of comet 8P/Tuttle passing very close in our sky to the triangulum galaxy, M33.


M33 is a popular spiral galaxy that lives relatively close to our milky way... somewhere around 3 million light years away. comet 8P/Tuttle is roughly 40 million kilometers (or 2 light-minutes) away. M33 looks blue due to the many regions where young stars are forming in the spiral arms. the comet looks green/teal due to its chemical composition.

on a clear night you might be able to see the comet from northern latitudes with your eye (although i havent had any luck from austin). binoculars or a small telescope should give a good view. while youre at it, try to find the still-bright comet holmes!

the astronomers are coming!!

next week austin hosts the 211th american astronomical society meeting. i'm super excited... and a bit anxious. in addition to the typical socializing, shenanigans, science, and sight seeing, i'll be giving a talk describing my dissertation research, trying to get some insightful research ideas, and schmoozing with people hiring post-docs!

for those who will be in austin, there is an official blogger meet-up tuesday night with the usual suspects: phil plait of bad astronomy and fraser cain of universe today. i'll show up at the iron cactus around 9pm to enjoy a margarita and good conversation.

look for exciting astronomy news revealed to the world all next week!

clock of nines

the 7 o'clock isn't exactly equal to 7, but i dont mind rounding up.... i'm not that big of a nerd! cool clock!


link: here

quadrantids meteor shower tonight

you have to say that word out loud... quadrantids.

if youre up late tonight in the northern hemisphere, look to the northeast... try to find the big dipper and then watch for bright meteors shooting across the sky! the quadrantids meteor showers have been observed and recorded since 1825




if you stay up late enough.... or wake up early enough tomorrow morning, look up at the incredibly bright planet venus, and the sliver moon nearby. enjoy!

carnival of space #35

the first space carnival of 2008 is available at music of the spheres!

but i can see the light!

phd comics

earth at perihelion

its cold right now in the northern hemisphere (even in austin), but the earth is closer to the sun today than it has been for the last year! this position is called perihelion. the earth's orbit around the sun is very nearly circular, but not quite. the image below shows circular orbits as dotted lines for mercury, earth, and mars... and the actual, elliptical orbits as solid lines.


you can see that the earth is very close to having a circular orbit (e = 0.0), but its slight eccentricity (e > 0) means that there is a point during our year where we are closest to the sun - today! happy perihelion!

intuitively, one might think that we would be closest to the sun during the hottest part of the year. but remember that the seasons are opposite for the northern and southern hemispheres. the reason for earth's seasons is because of the tilt of earth's spin axis relative the plane through which we move around the sun.

the effect of the changing distance between the earth and the sun, in combination with the earths spin axis, reveals itself by the analemma - the figure 8 pattern that the sun makes across the sky. the image above results from combining images taken at local noon on various days throughout a single year (see a movie here).


the point when the sun is highest in the analemma (and abve the horizon) is the summer solstice, and the lowest point represents the winter solstice. the rising and lowering of the sun's position in our sky is caused by the earth's tilted axis. the width of the analemma and the fact that the top loop is smaller than the bottom loop are due to the ellipticity of our orbit around the sun... the earth moves more quickly through space when we are closer to the sun in our orbit.

so what do analemmas look like on other planets in the solar system? here's a digital illustration of the martian analemma:


each planet has a different shape to its analemma because each planet in our solar system has a unique combination of axis tilt and eccentricity of orbit. to explore the analemmas from other planets, i send you off to analemma.com which has some very interesting, and slightly disorienting, videos!

the real stars of new years eve

if youre running around outside tonight at your local midnight, making noise and welcoming the new year... look up! find the orion constellation, focus on the bright orange mars, and reflect on the earth's recent trip around the sun.

the three stars of orions belt point down toward the bright star sirius.


the the left of the star betelgeuse, in orion, is the bright planet, mars.



enjoy! i hope the new year brings happiness for you all!

sagan's cosmos of TV!

carl sagan has remained a very positive influence in my life and has written amazingly inspirational prose about the human perspecive and our place in the universe.

sagan and ann druyan produced a TV series called COSMOS in the 1980's, and i'm happy to share that the Discovery Channel will be airing it in its entirety starting january 8th!!

the COSMOS series doesnt have the super high-tech animations that are shown in the universe series on the history channel, because it was created in the 80's. but its information is still up to date, and i like the amount that it left to be filled in by my imagination.... and the passion and wonder portrayed in this series is unrivaled in anything i've seen since.

you can see little snippets from the COSMOS series on evolution and the timeframe for human existence in the universe.

here's the beautiful introduction to the TV series:


enjoy!

robot ride

when boredom creates awesomeness:

moon passes near regulus

the moon is passing quite close to many objects this month as it travels thru the sky. tomorrow night (thursday dec. 27), the moon sits next to the bright star regulus and hangs above the planet saturn. saturn rises around 11 pm in the east and then moves up and across the sky throughout the night. enjoy!

mars and orion

wishing everyone a peaceful and happy day!

family fun time

me, my grandma, my niece areya and nephew keldan

the moon and mars

happy solstice everyone (a few days late!)!

did you notice the full moon tonight with the bright planet mars right next to it? for some lucky people around the world, the moon passed right in front of the orange-y planet, but not all of us could see this occult.

today's feature image comes from my very own older sister, Lara.


another nice shot from APOD today: an almost full moon as it passed near mars in our sky last month.

whole corn - cornhole

i've played this game almost exclusively in the midwest part of the US. i didnt realize how popular it has become in the cincinnati, ohio area. apparently this game is developing cultish participation levels! watching this tribute video yesterday brought tears to my sisters eyes!!


and if you thought that was funny, watch some more of the clever videos by rhett and link. i particularly like their rendition of the reading rainbow theme song and the drive-thru rap: healthy version.

dear body!

dinosaur comics

welcome, mars!

tonight mars is at its closest point to us for the next 8 years.... at about 88 million km (55 million miles) away! this is pretty close, but still 32 million km (20 million miles) farther away than in august 2003 (you may recall the "mars will look as big as the moon" hoax emails that started around that time).

mars looks bright and orange as it slowly moves across the evening sky near orion.

painting the world?

"a single tin of paint can pollute millions of litres of water."



effective message from the world wildlife fund (WWF).

grazing lunar occultation of saturn

they have chosen the top astronomy pictures of 2007 at APOD. there are some great shots, but surprisingly, they dont overlap with phit plait's astronomy images of the year. good thing we're making such good use of our telescopes!

my favorite shot by APOD, was taken in march when the moon passed just in front of saturn, barely blocking some of the rings and the side of the planet! a grazing lunar occultation!


to create the above image, pete lawrence of digital-astronomy, took one shot every 90 seconds during the occultation.... the moon is moving pretty quickly! then he adjusted each image so the light from saturn and the moon would contrast each other nicely instead of the bright moon dominating the entire image. then he added the frames together for this wonderful composite image!

seasons greedies

a question of consciousness

i wonder about the distinctly human quirk of consciousness. on earth, humans are the only creatures (as far as we can tell) who have developed the ability to recognize consciousness and contemplate existence. (i think we would live very different lives on this planet had we been competing with another intelligent species all along, in addition to ourselves and each other.) many animals share our five senses and even though the details vary greatly, only humans have developed the capacity to reflect on consciousness, invent written languages, and think deeply about things that are not directly related to our daily survival.

what about life on other planets (which surely exists)? does biological evolution always create consciousness after some period of time? maybe other life forms have seven senses or breathe primarily nitrogen, but if they've developed intelligence as we've come to know it, surely they have thought about science and psychology. my presumption is that the fundamental laws of physics we've discovered would be the same for these life forms. even if no creatures in the universe fully understand the fundamental laws, as we certainly don't, the laws should be equivalent. gravity would behave in the same, inescapable, familiar way that the force between the life form and its planet would decrease by the square of the distance between the life form on the surface and the center of the planet. this seems reasonable to me... but what about consciousness? is it always the same?

just as animals on earth have no concept of cognitive awareness, is there an equivalent level of something that we humans have not evolved to be able to feel/think/recognize/attain/comprehend? i try to think of emotions that could exist that humans have not experienced, but my list of possibilities (empathy, love, fear, depression, anger, etc...) seems as comprehensive as i can contemplate! will our human creation of potentially conscious robots give us more insight to the possibilities?

i mean, i'm not really looking to further complicate my humanoid life with even more concepts that i don't understand... but its fun for this feeling, loving, learning, creating, evolving, intelligent, bipedal, earth-bound, carbon-based, biological, talking collection of atoms to contemplate such circumstances!


these thoughts developed today as i watched the following video from the march 2007 TED talk by the 1969 Nobel Prize winner in physics, murray gell-mann. his talk is titled: beauty and truth in physics.

holiday cards

if youre still looking for holiday cards to give out with your presents, here are some of my favorites. the clever folks at hubblesite have created some wonderfully inspired hubble holiday cards.





i also found a neat collection of lucasfilm holiday cards over the last 30 years!

disappearing car door!!

why fix something when it's not broken? since cars have had doors, the doors have pretty much behaved the exact same way. i had never even considered an alternative to the way a door opens, because i never had a problem with existing door hinges.... but i'm glad someone was thinking about it because this is awesome!!!!


disappearing car door: link

carnival of space #33

carnival of space #33 is up at universe today. enjoy!!

best astronomy images of 2007

as the year winds down, people seem to like to produce their "best of" lists for the year. the bad astronomer, phil plait, has produced a beautiful list of his top ten astronomy pictures of 2007, complete with informative explanations about what youre seeing! check it out!

i'll add a favorite picture of mine from this year.... comet mcnaught over patagonia in south america, showing the disk of our milky way galaxy in addition to the two strange galaxies: the large and small magellanic clouds! (see full explanation here)

spiders want to go to space too!

the space shuttle atlantis sits peacefully waiting for its launch for STS-122. the launch has been scheduled and postponed many times in recent weeks. its currently scheduled for launch on january 2, 2008. a nice new year treat! in the meantime, folks at NASA have been preparing for the launch and fighting off giant spiders that might want to tag along into space ;)

UTs old telescope

last weekend was the last for my stint as the star party host for UT's old telescope. friday night's sky cleared up nicely, but only 2 people showed up to the party! so i had lots of time to look at mars, and the pleiades and take pictures of the telescope. the main lens in this refracting telescope is 9-inches in diameter and was crafted in the 1890s! the mount-structure was built in the 1930's and it has been there ever since!


there are absolutely no electronic parts running this old beast. the telescope stays pointed at stars because of the mechanical clock drive.


there's a weight that hangs down inside the mount and slowly unwinds the gears by the force of gravity. the system is calibrated to move the telescope very slowly in order to move the telescope in the opposite direction of earths rotation, but at the exact same rate. in this way, the telescope follows the stars as they travel westward across the sky and i dont have to constantly re-align the telescope every couple minutes!! every hour or so, i have to wind the mechanism.... if there are kids around, i let them wind it because they get *so* excited to participate!


the kids also love the manual right ascension wheel that looks like an old pirate ship steering wheel. its a good thing i can lock this because kids always run up to it and try to turn it!

geminid meteor shower

this friday, december 14th, 2007, peaks the last and best meteor shower of the year!! start looking up late each night this week to see a few cosmic fireballs streaking across the sky, but friday night provides the best show! starting after 10pm, local time, look to the left of the constellation orion, toward mars and the constellation gemini. after midnight, you might be able to see a dozen "shooting stars" each hour... and the moon will be just past new so the sky will be dark!


astronomers first noticed the geminids (relatively recently) in 1862, but didnt realize their unusual origin until 1983. all other meteor showers are caused by earth passing through the dusty remains of a comet tail, as we saw for the orioids meteor shower in october. the geminids originate from earth's orbit passing thru a place in space where the near earth object, 3200 Phaeton, passed. this object is classified as an asteroid, which does not have the debris tails that cause comets to leave behind stuff that evaporates in earths atmosphere. here's an image of a comet (hale-bopp) and an (up close) asteroid (951 gaspra) so you can see the lack of loose stuff around an asteroid!




so what has happened to cause the geminids? the theory is a bit controversial, but many believe that 3200 Phaeton is the central rocky remains of what was once a comet! the orbit of 3200 phaeton is elliptical and passes very close to the sun, which are characteristics of comets, not asteroids. you can read more from NASA, but in the meantime... enjoy!!

(the first photo of the geminids was taken by Fred Bruenjes in 2004.)