Reddest of the Red Stars by Vincent S. Foster Some stars will have you seeing red. They’re carbon stars, a unique type of variable star, which accumulate soot in their upper atmosphere that scatters light near the blue end of the spectrum. What’s left for us to view is the red component of a star’s light. As the carbon particles build up, the star fades in brightness and gets even redder. Eventually, the carbon absorbs enough radiation to escape the star, and the cycle starts over again. Novice stargazers are often disappointed because they cannot see the rainbow of colors that appear in celestial photos taken by the Hubble Telescope. This is because the human eye’s color sensors do not function well under low light levels. So why can we see the color of carbon stars, but not that of most other celestial objects? Because their light is both bright and concentrated into a point rather than being spread out like nebulae and galaxies. Aim binoculars or a small telescope at a carbon star and you’ll see its color even more prominently. That’s because the scope will gather much more light than your eye and will help stimulate your color receptors. Although carbon stars are the reddest of the red stars, there are different levels of red in these stars. Astronomers determine a star’s redness by observation and simple math. They measure the star’s magnitude through blue (B) and visual (V) filters. Then they subtract the visual magnitude from the blue. This leaves a number designated B-V called the color index. The more positive the color index, the redder the star is. For example, if a star has a blue magnitude of 5 and a visual magnitude of 3, then it has a color index of 2. Color indices range from about -0.5 for the bluest stars t... ... middle of paper ... ...orite with a color index of 4.4, making it a visually striking red star. Its magnitude ranges between 7.8 and 9.3 over 369 days. If you want more carbon stars to observe visit the website of the Saguaro Astronomy Club in the U.S., which maintains a database containing 334 red stars. Go to www.saguaroastro.org The Astronomical League in the U.S. also has a list of 100 carbon stars as part of its Carbon Star Observing Program. It can be downloaded at www.astroleague.org Carbon stars will please your eyes and help sharpen your observing skills. If you keep an observing log, you may exhaust your thesaurus searching for different ways to say “red.” One thing’s for sure, though. Looking at these red stars won’t leave you feeling blue. END Word Count: 1,544 Vincent S. Foster 37 Brigantine Blvd. Waretown, NJ 08758 USA Tel: 609-488-5898 Email: grantfinder1@aol.com
...mation about colorblindness and color deficiencies. Color wheel images used in this paper were taken from this site.
At a distance of 525 light years, blue class B (B1) Hadar is 130 times farther away than Rigel Kentaurus, and is bright because it is truly and very generously luminous, shining (accounting for the ultraviolet radiated from the 25,500-Kelvin surface) 112,000 times more brightly than the Sun. Hadar, however, is not one star, but two. Sophisticated observations that rely on the interference properties of light show that the single point of light actually consists of a pair of nearly identical stars each some 55,000 times more luminous than the Sun separated (from our perspective) by only 2.5 astronomical units. The temperature and luminosity show each to contain 15 solar masses. Spectra suggest an orbital period of not quite a year, this and the masses rendering them an actual 3 astronomical units apart. Twin Hadar also has a fourth magnitude sibling 1.3 seconds of arc away that, because of the brightness difference, is difficult to see and study. A class B dwarf, Hadar- B is a grand star in its own right, a star of 5 solar masses 1500 times more luminous than the Sun; it only pales by comparison with Hadar (or the Hadars) proper.
One of the main types of nebulae is called a reflection nebula. The particles around stars are about the same size as the wavelength of visible light and therefore they are able to reflect the visible light being emitted from the nearby star. However, most of the time these clouds of dust have a bluish color to them and that is due to the fact that the particles are at about the same size as the blue wavelengths and it is harder for them to interact with the longer red or orange wavelengths. The best reflections nebulae come around stars that are cooler than 25000 K. Another main type of nebula is an emission nebula and this type derives its light from the UV radiation being emitted from a nearby star. The light from the starts exites atoms in the dust cloud which in turn emit light. . When describing what happens to light coming from a star there are two things that refer to it. One would be extinction and this happens when the dust cloud around the star is so dense that the light cannot pass through it and it appears as if the light just stops or makes the star appear dimmer than it really is. Another one would be reddening and this happens when the dust particles in the interstellar medium pass the longer red or orange wavelengths. This process gives the clouds a reddish color and overpowers the blues, greens , and violets.
During this lab we utilized the HR Diagram Explorer to complete the experiments in our lab. We adjusted the different temperatures (x-axis) and luminosity (y-axis) and were able to see the stars plot on the diagram. This diagram shows the different categories of stars; Supergiants, Main Sequence, Dwarfs and the many others. The stars that where mostly plotted in the middle are the Main Sequence stars. These star make
2, Alter Dinsmore, Cleminshaw H. Clarence, Philips G John. Pictorial Astronomy. United States: Sidney Feinberg, 1963.
In the Northern Hemisphere, Betelgeuse can be easily seen with the visibility being at its peak in the winter months. This star is orange-red in color
Well, it all depends on the different gases in the Earth's atmosphere and the height the gas is in. The red around the arc, cloud, or streak shapes are nitrogen molecules they're low in the atmosphere at about "100km/60 miles" (www.athropolis.com) yet the red in the shape is oxygen in a high altitude "above 300km/185 miles." (www.athropolis.com) The yellow/green color is oxygen in low altitude "between 100-300km/60-185 miles." (www.athropolis.com) The blue and purple are hard to see in nights sky but they are created by hydrogen and helium in high altitude Some of them move, brighten, or flicker all of a sudden. You could see them more "during the most intense phase of the 11 year sunspot cycle." (The World Book Encyclopedia, 895-896)
‘Cones are active at higher light levels’, this is called photopic vision. There are about 6-7 million cones, they are split into three categories; Erythralobes, red (64%) that have maximum absorption at 565nm and are also known as long wavelength cones (l-cones). Chlorolabe, green (32%) have a maximum absorption at 535nm are also known as middle wavelength cones (m-cones). Cyanolabe, blue (2%) have a maximum absorption at 430nm, also called short wavelength (s-cones) that enable the eyes colour sensitivity. The red and green cones are mainly concentrated in the Fovea centralis which is located in centre of the macula of the retina and responsible for sharpening the central vision, this area consists of very thin densely packed cones and is a rod free region. The blue cones have maximum sensitivity and can be found mainly outside the fovea, which may lead to a few distinctions in the eye’s blue perception. Cones usually only take five minutes to recover from sensitivity.
Stars are born in the interstellar clouds of gas and dust called nebulae that are primarily found in the spiral arms of galaxies. These clouds are composed mainly of hydrogen gas but also contain carbon, oxygen and various other elements, but we will see that the carbon and oxygen play a crucial role in star formation so they get special mention. A nebula by itself is not enough to form a star however, and it requires the assistance of some outside force. A close passing star or a shock wave from a supernova or some other event can have just the needed effect. It is the same idea as having a number of marbles on a trampoline and then rolling a larger ball through the middle of them or around the edges. The marbles will conglomerate around the path of the ball, and as more marbles clump together, still more will be attracted. This is essentially what happens during the formation of a star (Stellar Birth, 2004).
Shklovskii, Iosif S. Stars: Their Birth, Life, and Death. Moscow: Central Press for Literature in Physics and Mathematics, 1975.
This is because of the brightness of the planetary system's host star. A host star, like the three Alpha Centauri stars, outshine planets in the solar system because planets are too dim. However, the mid-infrared wavelength range will make observing exoplanets in the Alpha Centauri system easier for scientists. This is because "the thermal glow from an orbiting planet greatly reduces the brightness gap between it and its host star."
...ve different colors, colors tell about a star’s temperature, composition, age, size, and distance. Red stars are usually older; coolers stars have used up much of their hydrogen fuel. Blue stars are much younger and hotter. Most of Orion’s stars are blue except for the very red star, Betelgeuse. Orion is most easily seen from the months of November through February. The latitudes at which Orion can be best seen are 85 and -75 degrees. Its right ascension is 5 hours, and its declination is 5 degrees.
There are 3 different types of cone cells in the human retina “the L, M, and S cones” that can respond only in certain wavelengths of light “short, medium, and long lengths”. Through the opponent process the color experience is measured from those three distinctive signals. With the knowledge of the univariance principle, we need to always take into account that the firing cells always depend on the number of photons absorbed. The three responses of the three different cones are determined by the respective photoreceptor proteins having the ability to absorb the photons of the many different wave lengths on light. So, for example, an S cone cell contains a photoreceptor protein that more readily absorbs short wavelengths of light (i.e., more "blue"). Light of a longer wavelength can also produce the same response, but it must be much darker to do
Light is what lets you experience colour. The pigment of the retina in your eyes is sensitive to different lengths of light waves which allows you to see different colours. The wavelengths of light that humans can see are called the visible colour spectrum.
Earth’s galaxy, the Milky Way consists of more than 100 billion stars, many of which can be interpreted by human visual perception, while other can only be observed with the aid of a magnifying or light-collecting optical device such as a telescope. The stars are organized into various groupings according to their visible arrangement as observed in earth’s atmosphere. Human beings from cultures of eras bygone such as the Greeks, Romans, and Babylonians, and bestowed most, if not all of the titles upon the constellations as we know them today. Earth’s atmosphere comprises eighty-eight constellations, of which I have chosen the following five to discuss for my laboratory report: Andromeda, Big Dipper, Cassiopeia, Cepheus, and Draco