The solar chromosphere is made almost entirely or entirely (certainly for the upper chro- mosphere) of jets known as spicules, with lifetimes of approximately 15 minutes with hun- dreds of thousands on the Sun at any given time (Beckers, 1968). There have been numerous investigations over the decades of spicules, for example, Roberts (1945), Lippincott (1957), and Dunn (1960)studied themat the polar limb. A spectroscopic study at the Sacramento Peak Observatory by Pasachoff, Noyes, and Beckers (1968)provided direct evidence of spicular motion, overcoming limitations of apparent motion derived from series of intensity images that may have resulted merely from changing ionization fronts instead of actual ve- locities. In addition to rising and falling motion along the limb, Pasachoff, Noyes, and Beck- ers also reported evidence for rotation of spicules. Mouradian (1965, 1967)alsoprovided spectroscopic measurements of spicular motions, and Lynch, Beckers, and Dunn (1973)and Nishikawa (1988)later remeasured size statistics. See alsoZaqarashvili andErdélyi (2009). Generally, the term spicules refers to the features seen at the limb of the quiet Sun (Golub and Pasachoff, 2001), and this paper deals exclusively with such “classical” spicules. Similar features seen on the disk are called “mottles,” although some authors refer to those features as spicules as well. Beckers (1968, 1972)gives comprehensive reviews of earlier work on spicules, as well as mottles. Active consideration of limb spicules revived at the time of the 1998 total eclipse with a meeting on Solar Jets and Coronal Plumes on Guadaloupe (Koutchmy, Martens, and Shibata, 1998). Reviews of spicules were given by Suematsu (1998)and, fromtheoretical considerations, bySterling (1998a). Those presenting new ob- servations included Salakhutdinov and Papushev (1998), Zirin and Cameron (1998), and De Pontieu et al. (1998), Budnik et al. (1998), and Dara, Koutchmy, and Suematsu (1998). Sterling’s paper included numerical simulations based on the deposition of thermal en- ergy in the middle or upper chromosphere, perhaps as microflares (Sterling, Shibata, and Mariska, 1994;Sterling et al., 1991;Sterling, 1998b). Observations in theUVandEUValso reveal features with spicule-like properties. For ex- ample, from observations made from a rocket, Dere, Bartoe, and Brueckner (1983) observed EUV chromospheric jets that they identified with spicules though their lifetimes were about 10 times shorter. Chae et al. (1999)have usedTRACEdata togetherwith their ownBig Bear Solar Observatory data to comment on EUV jets and their relation to solar microflares. They dwelt on the Fe XII images at 195 Å from TRACE, comparing them with Hα in an active region on the disk.
High precision spectrometers such as HARPS are required to preform observations as very high signal to noise ratio. HARPS is a high resolution fiber-fed echelle spectrograph. To maximize the chance of detecting an exoplanet certain requirements have to be met by potential targets. The targets chosen to be studied by HARPS are selected from COR...
winds of Miras are believed to be driven by a combination of dust formation and shocks induced by stellar pulsation. (Willson). Understanding the nature of shocks and measuring their properties is essential to understanding the physics of pulsation and mass loss from pulsating stars.
The sensitive instruments aboard the SOHO spacecraft have already helped scientists here on Earth discover and explain some of the mysteries of the Sun as well as to confirm some of their theories they previously held. For example, in May of 1998 with the help of the Michelson Doppler Interferometer scientists were able to see with greater clarity the giant convective cells inside and on the surface of the Sun.
More than 50 years after the publication of Astronomiae Pars Optica, another man was carrying on Kepler’s work in the field of optics....
According to Cox the explosive depth of the clouds that remained unchanged after traveling millions of light years are more powerful than before, pulling more gas and gravitational pull. At the time, these clouds meet up at any specific point the force make them move in a clockwise rotation and hence a tornado is formed. These fast moving spinning air balls rotate in vertical columns’, this process has been a cause of the formation of the present solar system, more than billions of years
2, Alter Dinsmore, Cleminshaw H. Clarence, Philips G John. Pictorial Astronomy. United States: Sidney Feinberg, 1963.
Anonymous. (1998). A closer look at Hubble's Variable Nebula. Sky and Telescope, 95, 24-25. Retrieved April 17, 2016, from http://web.a.ebscohost.com.ezproxy.library.uwa.edu.au/ehost/detail/detail?sid=e3eaa20f-cd07-4589-9e1a-64af362890ae%40sessionmgr4001&vid=0&hid=4207&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d&preview=false#AN=170864&db=f5h
The extreme brightness of the O-type and B-type stars, coupled with the Earth’s atmosphere, has always made high-resolution imaging of the star-forming region difficult. But recent advances in adaptive optics and the repair of the Hubble Space Telescope have allowed for incredible detail into the center of the dust cloud. 3 The technological advances have also helped reveal several faint stars within the center of the nebula.
No two astronomers made quite as significant contributions to their field during the European renaissance like Nicholas Copernicus and Tycho Brahe. There were serious flaws to the widely-accepted Ptolemaic model of the solar system, and these two scientists sought out to correct those flaws. While their approaches and models were very different, the most prominent and new feature of their models were revolutionary and accepted today.
Research News Planetary Scientists are Seeing the Unseeable Richard A. Kerr Science, New Series, Vol. 235, No. 2 -. 4784. The. Jan. 2, 1987, pp. 113-117. 29-31. The 'Standard' of the 'Standard'. Stable URL:
A star begins as nothing more than a very light distribution of interstellar gases and dust particles over a distance of a few dozen lightyears. Although there is extremely low pressure existing between stars, this distribution of gas exists instead of a true vacuum. If the density of gas becomes larger than .1 particles per cubic centimeter, the interstellar gas grows unstable. Any small deviation in density, and because it is impossible to have a perfectly even distribution in these clouds this is something that will naturally occur, and the area begins to contract. This happens because between about .1 and 1 particles per cubic centimeter, pressure gains an inverse relationship with density. This causes internal pressure to decrease with increasing density, which because of the higher external pressure, causes the density to continue to increase. This causes the gas in the interstellar medium to spontaneously collect into denser clouds. The denser clouds will contain molecular hydrogen (H2) and interstellar dust particles including carbon compounds, silicates, and small impure ice crystals. Also, within these clouds, there are 2 types of zones. There are H I zones, which contain neutral hydrogen and often have a temperature around 100 Kelvin (K), and there are H II zones, which contain ionized hydrogen and have a temperature around 10,000 K. The ionized hydrogen absorbs ultraviolet light from it’s environment and retransmits it as visible and infrared light. These clouds, visible to the human eye, have been named nebulae. The density in these nebulae is usually about 10 atoms per cubic centimeter. In brighter nebulae, there exists densities of up to several thousand atoms per cubic centimete...
Perhaps one of the most interesting features of our fathomless universe are the planets that are classified as gas giants. Huge, turbulent, and distant, the gas giants are some of the most enigmatic features in our Solar System. I have a personal interest to the gas giants and celestial bodies in general. When I was a child, I was fascinated by our Solar System. I read innumerable books about space, and my interests of outer space had been piqued further by other forms of media. Although I held this interest of space, growing up left me with little time to learn about space, and I lost interest for a while. Taking Earth Science in Milpitas High re-invigorated my interests in the celestial bodies. Using this class, I’m now able to focus on learning more about our colossal universe, in particular, the outer planets.
Tyler, Pat. Supernova. NASA’s Heasarc: Education and Public Information. 26 Jan. 2003. 22 Nov. 2004
Violent eruptions of gas on the Sun’s surface called solar flares can send solar charged particles towards Earth and appear to be possible threats to the safety of mankind. These expulsions of charged particles come from the sun flares’ relationship with sun spots. Sun spots are cooler and darker regions of the Sun where the solar magnetic field extends off of the Sun’s surface. When the charged particles ejected from the sun reach Earth and enter its upper atmosphere, they react with present atoms and can cause major disturbances to satellites and terrestrial communications systems such as T.