APOD 6.7

Winter is here, and in places where it actually snows--like this area near Madrid, Spain--the ice crystals morph the atmosphere into a giant lens, arcs and halos forming around the sun or the moon (whichever is visible at the time). This sky displays the moon with not one, not two, not even three, but four halos radiating from the bright face. The lunar beams refact through hexagonal ice crystals which creates a 22 degree halo around her, while the elongated circumscribed halo is formed from column ice crystals. Here's where it gets interesting: the third rainbow ring forms from yet another refraction at a 46 degree angle thanks to distant ice crystals, and the fourth and final ring at 46 degrees makes this a quadruple halo; twice as cool as a double rainbow. In the distant celestial scape, Betelgeuse, Sirius, and Orion's Belt are visible, all over the landscape of Puerto de Navacerrada in the mountain range of Sierra de Guadarrama.

APOD 2.5

E.E. Barnard, in the early 1900s, spotted a strange stretch of dark marks east of Scorpio's bright star Antares and in the constellation Ophiucus, behind B59, B72, B77, and B78, the dark nebula known commonly as the "Pipe Nebula" (due to its shape) painted in the stars with interstellar dust. The dense cores (located around 450 light-years away) collapse to form new stars. This picture was taken in the Chilean Atacama Desert with 24 hour exposure and maps out a 10 degree by 10 degree field.

Constellation Quizzes

This index has five different constellation quizzes, one for summer, winter, spring, fall, and on top of that the circumpolar ones!

This one is really interesting too, though it's more recognising elements within the constellations and facts abuot each of them (which is helpful for those little things!)

APOD 2.4

Aloha! Reporting from the North Gemini telescope on Mauna Kea, this is not your regular stock image. Nope, this is NGC 660, floating in over 20 million light-years away within the limits of Pisces, presenting a rather odd appearance. NGC 660 is a polar ring galaxy, meaning that the dust, stars, planets, and so on all orbit around the galactic disc while sectionalised by rings, which in total span over 50 000 light-years. This is a rare moment for a rare sort of galaxy, for some sort of intersection caused a graviational pull that extracted some of the pink of forming stars and threw off the disc's usual configuration, leaving the trail of debris. Though you can't see it, in this picture lies an unseen halo...made of dark matter!

APOD 2.3

This backdrop that looks like a piece pulled from the Star Trek archives is the Spiral Galaxy Arp 188--also known as the Tadpole Galaxy--swirls 420 million light-years away, in the farthest north of the circumpolar dragon, Draco. The blue studded tail itself is 280 light-years in length, legend telling of an intrusive galaxy encountering the Tadpole long ago, disrupting the flow and using its own powerful gravity to lure out trails of dusty clusters, thus forming the tail before leaving. The other galaxy in this tail is the Cartwheel Galaxy, who lies 300 light-years away. Likely, as the galaxy ages, like a frog, the Tadpole will lose its namesake tail, the clusters forming orbiting satellites. Maybe within the next few thousand years, astronomers should consider calling it the Frog Galaxy!

OBS

This morning, beneath the moon, I spotted Venus and just below it Mars, at about 6:45 or so. Orion was clearly visible in the sky, and from his belt I followed and made out a rectangle sort of formation, which I at first wondered whether or not it was the Great Square of Pegasus, only to realise this was a mythical formation of my connect the dots imagination, actually seeing a few bright stars in Puppis and Canis Major.

APOD 2.1

Orion, the Hunter, houses the infamous and easily recognisable Horsehead Nebula, alternatively known as Barnard 33. In the 1800s, this distinct star nursery appeared in a photographic plate, the red colour coming from the hydrogen ionised by the bright Sigma Orionis. Thick dust forms the actual horse head, gas from the nebula funnelled by a strong magnetic field. It takes about 1500 years for light from the Horsehead to reach the Earth, seeing the 'baby pictures' of the bright spots of forming stellar objects.

APOD 2.2

The reflection of nebula VdB 152 (catalogued as CED 201) appears ghostly in the circumpolar constellation of Cepheus. This Halloween spectre (spanning a good 7 light-years) haunts the skies from about 1400 light-years away,  lying along the Northern Milky Way, blocking out the background stars with opaque blue dust clouds, red faintly illumining from the nebular dust around the edges in the ultraviolet spectrum. The cloud's velocity differs from its mother star's, wandering into the realm of the royal for a 2spooky night of tricks and treats.

APOD 1.8

Over the span of this beautiful October sky-view, from a cushy lakeside campsite in Northern Maine, two important objects can be observed. The Milky Way Galaxy span over the mountains, all aglow with a faint orange. Zodiacal light, a sweep of dust scattering sunlight along the ecliptic, stretches horizontally, the intersection with the Milky Way marked by a bright, shiny Jupiter. Past the star cluster Pleiades and to Jupiter's right is Gegenschein, the brightening of the Zodiacal which typically remains unseen unless the night is right. From behind the mountains, Begirt and many other stars rise, and in the lake is a reflection of the Hunter Orion.

Chapter 5 Sections 1-3 Outline

Telescopes capture as many photons as possible from a region of the sky, focusing the beam of raditation so astronomers may analyse it. Optical telescopes collect wavelengths visible to the human eye, a tool used for centuries and likely the most well known of astronomical instruments. Infrared and ultraviolet radiation, while invisible to us, is also a spectacle for most observed celestial objects as well.

An optical telescope can refract or reflect. Refracting telescopes use a lens to gether and concetrate a beam of light, bending it as it passes from one transparent meduim into another. The beam goes through the focus so an astronomer may take it in, with the distance between the primary mirror and the focus known as the focal length. Reflecting telescopes, meanwhile, use a curved mirror rather than a lens, utilising that to focus on incoming light. The collecting mirror is known as the primary mirror, and the focus of the primary mirror is referred to as the prime focus. Images are formed near the prime focus, capturing a scene of an entire field of stars. This image is magnified by the eyepiece, or otherwise recorded as a digital photograph.

Reflective instruments tend to be favoured over their refractive counterparts due to several facts. For one, in view of a refractor, light must pass through or else they will be left at a crucial disadvantage. Chromatic aberration is the deficancy suffered by these, for they disperse blue and red light differently. Some light can also be absorbed by the glass, creating minor visual problems and major infrared and ultraviolet issues. Larger lenses tend to be on the heavy side, and the lens will deform under its own weight. None of these problems occur with mirrors, which also have but one surgace that needs accurate machining and polishing versus the refractor's two, thus making reflection the simpler choice among light gatherers.

In reflective instruments, light is often intercepted on its focal path by the secondary mirror, redirecting it to a more convinient local. The Newtonian telescope illustrates the light intercepted before reaching the prime focus, then deflected by ninety degrees to the eyepiece. While this remains popular in small instruments for hobbiest amatuers, larger instruments rarely use Newton's design in favour of a Cassegrain telescope, in which the primary mirror reflects light to the prime focus and is then intercepted by a small, secondary mirror, which reflects through a small hole in the primary mirror's centre. Larger instruments typically result in more complicated forms of relfection, with more angles of reflecting for more precise and accurate measurements. The best known of the Cassegrain telescopes is the Hubble, measuring from infrared to ultraviolet waves on the spectrum.

Size and light gathering power are commonly associated, for usually the larger a telescope is, the more power it holds. The resolving power is another factor, for it can focus on more radiation than smaller counterparts and enable more in depth study of fainter celestial objects and gain more knowledge on the brighter ones too. The greater light collecting area allows more capability of gathering large amounts of radiation, increasing and enchancing viewing abilities. Angular resolution also grows finer with size, eliminating some of the cumbersome troubles caused by light's diffraction, which makes the image fuzzy. Diffraction-limited resolution is a quality which, as it states in the name, limits the diffraction and makes for a finer picutre that can be closely studied without unneeded fuzz.

Images coming in from the telescope are just as important, for they are just what the astronomers need to analyse. Charge-coupled devices--also known as CCDs--are widely used, these electronic detectors far more conventional than photographic equipment. The device consists of a wafer of silicon divided into pixels, an electronic charge building upon it when light hits it. The charge is directly proportional to the number of photons striking the pixel, transfering the intensity of said light into the image itself. They serve as much more efficent tools than photographic plates and show a higher level of detail while also possessing the nifty capability of digital duplication,making for easy access.

Computers reduce the unwanted background noise of astronomical images, taking away the static snow that corrupts telescopic images. Imperfections in the detector, interferences in the Earth's atmosphere, and faint, indecipherable noise coming from the cosmos contribute to this nuissance, but origin cannot typically be determined. Computers can produce a clean image that extract the noise and leave a clear picture.

The angle of light is inversely proportional to the accuracy of the focus, an increase in angle resulting in a decrease in clarity in an effect called coma. Thus, wide-angle views are not as common, for it is very easy to degrade the quality so much that the image cannot be salvaged and is a waste.

When a CCD is places at the telescope's focus, the telescope will act as a high-powered camera; however astronomers often desire more specific radation measurements than just that. The brightness is one of the most crucial components of star studies, the measure of such known as photometry. Filters limit the wavelengths measured by photometric images, and often three images result (taken with blue, red, and green filters respectively). Highly accurate and rapid measurements of light intensity typically are measured by a photometer, measuring the total amount of light recived in all or part of the field view.

Spectrometers study the spectrum of incoming light, redirected and defined by a narrow slit, then displaying a spectrum of light made of its components. This can be used to tell what element or elements dwell in the stars.

Tycho Brahe

Born in a circle of high nobility in the country of Denmark--then an expansive empire which bled into modern Sweden and Norway--Tyge, known more commonly by the latinised version, Tycho, Brahe was born in 1546 on the 14th of December. Jørgen Thygesen Brahe, brother of Tycho's father Otto, raised the young astronomer, educating him as preparation for being his heir. 

Tycho attended several universities, including ones in Wittenberg--where, in 1566, he lost the tip of his nose in a duel, leaving him to using a metallic replacement for the rest of his life--Rostock, Basal, Copenhagen, and Leipzig, his travels around the Germanic area and academia piquing interests in the celestial realm. Alchemy and astronomy caught his eye, his new impulses leading him to observe the cosmos upon his return to Denmark in 1570. 

A precursor to Brahe's claim to fame as documenter of the stars, he discovered a new star in the constellation Cassiopeia, writing about it in 1573 (a year after his find) before taking a job at the University of Cophenhagen lecturing on the science of the stars. A firm believer of the Aristotelian belief of an unchanging celestial sphere due to lack of parallax, he felt as though astronomy could be improved through accurate observations. 

Following another tour of the Germanic states, meeting up with various astronomers, King Frederick II funded Brahe's observatory on the island of Hven. Uraniburg, as it was named, stood as the best observatory of the time, housing newly innovated and calibrated instruments to aid Brahe in his extensive night time observations. There, he trained a new generation of budding astronomers before leaving Denmark after a dispute with King Christian IV. 

He became the Imperial Mathematician of the court of Emperor Rudolph II, settling in Prague to still continue his observing and training. Johannes Kepler, who developed the laws of planetary motion using Brahe's data years after his mentor's death, served as his assistant. At the age of 50, Brahe died on October 24th of 1601, suffering an exploded bladder following a banquet he attended in Prague, valuing party etiquette over basic human need for urinary relief. 

Several of his observation books survived, schooling future generations of the placement of objects in the heavens, which he described as moving in orbits. In 1572, he discovered a supernova--that being the new star in Cassiopeia--and created a geo-heliocentric universe (which his assistant later proved to be a solely heliocentric universe). 

APOD 1.7

In the too beautiful and glorious country of Norway, near the urban centre of Tromsø, two celestial spectacles occurred simultaneously in mid-September on one fateful night. Through a low green aurora shined a red one, the two overlapping to create a strange violet that streaked the sky (don't ask me how red and green make purple!). Then, bursting through the painted sky, the brightest fireball ever recorded by astronomer's eyes shot through the atmosphere, the meteor gifting the distant peak of Otertinden of the Lyngen Alps with a glowing halo round its peak. Several other times in history has such an event been recorded--numerous times in the Tromsø area--however this particular image offers a stunning reflection of the sky in the Signalelva River, as seen in the foreground.

APOD 1.6

The water bearer, Aquarius, houses a dying star seven hundred light-years away. NGC 7293, or the Helix Nebula, is the result of thousands of years on its deathbed, producing a well-studied paragon of a planetary nebula, as many stars will do towards the end of their scintillating days. The photo above is a result of 58 hours of exposure, ensuring the display of the hydrogen red ring and the inner area of oxygen aqua. In the rings, in a photograph taken by the Hubble, gaseous knots form in the detail of the cloud, between the inner region and outer halo. The darker, more prominent inner region spans about 3 light-years, while the faint halo expands its length to over 6 light-years across. The white dot at the centre is the hot and dying star. While this nebula looks simple, it has a complicated geometric structure.

Observation Oct 4

At approximately 6:35am, upon leaving the house to head off to school, I looked up at the sky to see the fading celestial sphere overhead (as my father drives a convertable giving me this oppurtunity to look at the skies often when going to Pine View). I was happy to spot Orion, recognising his belt immediately, the Hunter standing at about 45 degrees in the night. I proceded to watch him during my trip from my home on Siesta Key to Osprey, and only around the Bay Street traffic light at around 6:50am. I could not make out the redness of Betelgeuse, but seeing Orion early in the morn did improve my day.

Tycho Brahe Sources

Gow, Mary. Tycho Brahe: Astronomer. Berkleley Heights, NJ: Enslow Publishers, 2002. Print.

Tycho Brahe. The Galileo Project, 1995. Web. September 27 2012.

APOD 1.5



The bright star in the corner marking part of the asterism known as "The Great Square" is the bright star Markab, Alpha star of the constellation Pegasus, also known as the Winged Horse commonly. The dusty clouds appear courtesy of a blue reflection nebula less than a thousand light-years distant, this area looking away from the Milky Way plane littered with molecular clouds. This image shows a span of about five degrees--ten times the diameter of our moon--and in the background are galaxies far off (once past the Milky Way), such as NGC 7497, as noted by its prominent spirals.

OBS 9.21

Being sick all of the previous week, I seldom had a chance to look up at the stars, tied to my bed and unable to report much other than "It's dark outside."

Regardless, just the other day, as instructed, I went out at around eight to see Mars adjacent to the moon, a fine and lovely sight. Other than that, though, I missed most of my chances to look at the celestial sphere.

APOD 1.4

Aki Hoshide, the third Japanese astronaut to walk in space and Expedition 32 flight engineer, took this picture during his third session of EVA (extravehicular activity), taken while arguing the capabilities of the ISS, International Space Station. The Sun shines in the upper left corner, while reflected in the visor is the Earth, portions of a mechanical arm, Aki himself, a ring of space, and the Earth observing camera launched into space mid-summer. Yesterday, this Expedition ended, the Soyuz spacecraft capsule unlocking from the ISS and bringing the crew out from the Heavens and back to the Earth. 

APOD 1.3

Making up for last week's lost report, here is an elaborate, cluttered star-field two degrees in range of the constellation Cygnus, known both as the Swan or Northern Cross. However, the main point of interest is the eye in the cosmic Cocoon Nebula, roughly four thousand light years from Earth, the eye being the bright spot at the end of a trail of starless space. IC 5146, as it is known in the catalogue, expands for fifteen light years. The red glow of the eye signifies hydrogen gas, all stimulated by dust-reflected starlight (like the Witch Head Nebula) which would otherwise be invisible to the molecular. The centre star, scientists believe, is hundreds of thousands years old (but just a few!), its glow like the Young Cluster and clearing a space for the forming dust and gas of stars. As much as this does show, more stars hide behind the screens of dust.

APOD 1.2

Emission nebula IC 4628--which goes by an array of names such as Gum 56 (as its Australian discoverer Colin Stanley Gum dubbed it) or The Prawn Nebula--sits in the nebula tail of the constellation Scorpius, south of its heart bright star Antares. The radiation of ultraviolet rays from enormous stars only millions of years old strips atoms of their electrons, which then assimilate and produce a red nebular glow (the red deriving from the hydrogen content). This nebula fosters several clusters of clouds, including Collinder 316, Trumpler 24, and Sco OB1, making it the jewel box of Scorpius. Vela and Puppis are two constellations located near the nebula, being swallowed up by it's sprawling expansion thought to the result of a supernova. On the celestial sphere and from an earthly view, the nebula appears to be roughly four moons across, its actual length around 250 light-years, as the real nebula is estimated to be over 6 000 away.

OBSV: First Two Weeks

Due to the tropical storm, many of my nights of viewing the Heavens were spoiled, leaving me looking at only clouds above (if otherwise getting rained on).

One night I was, however, able to observe several of the zodiacal constellations adjacent to the moon--Scorpio, Sagittarius, and Libra. Along with that, I did see a lovely full moon on that night, much larger than usual.

When walking out to head to school in the morning, I did observe Venus higher in the sky, but had no time to look for Mars.

APOD 1.1

According to the catalog, this site is known as NGC 7635, but most simply use the common name of "The Bubble Nebula". 11 000 light-years away from the Earth and a good 10 light-years in diameter, it contains a cloud of expanding gas, thus resembling a bubble, as the central star of the system--the O star--emits radiation, heating the cloud against a denser material in a surrounding molecular cloud, and creating a glow, giving it a sheen. It inhabits the sky adjacent to Cassiopeia (the Seated Queen) and may perhaps be a part of a larger complex of celestial objects.