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SUPARCO - ASTRONOMY & ASTROPHYSICS BULLETIN Volume I, Issue 7 July, 2012 Sky watching: Naked Eye Phenomenon Pakistan Space Vision-2040, was approved by the Prime Minister of Pakistan which inter-alia included augmentation / strengthening of the Astronomy and Astrophysics programmes of SUPARCO. SUPARCO`s astronomy and astrophysics program is mainly focused on theoretical and observational research. For this an astronomical observatory is planned to be established. Research studies pertaining to deep space objects including galaxies, nebulae and variable stars are also being initiated. Search for earth like planets is a hot topic in astrophysics nowadays. It is planned to conduct research studies in this field also. Inside this Issue: Sky watching: Naked eye Phenomenon Looking at the sky for observation of heavenly bodies is usually termed as sky watching. Each object in the sky has its own exquisite loveliness. Besides the stars, there are planets, the moon, shooting stars and comets to observe. If no special events are there, people can even observe certain naked eye sky phenomena. These phenomena require no instrumental aid and any one can observe these phenomena. Some of them occur in the earth’s atmosphere in daytime and some in the nighttime. These include rainbows, auroras and meteors for example, occurring just few miles above the earth surface. Atmospheric effects on sunlight Sunlight reaches earth after travelling 93 million miles The passage of sunlight through the atmosphere, changes it’s properties and sometimes causes various atmospheric phenomena to occur. Halos: One of these is the “Halo” around the sun and the moon. High in the atmosphere, the six-sided ice crystals in cirrus clouds refract (or bend) light in the same way a prism does. This creates a halo around the Sun with a radius of 22°. Halo around the sun are sometimes not noticeable because of its glare but people can perceive when the sun is obscure by objects or buildings. White Dwarf Stars Book Review Ecliptic Sky this Month Web Review Software Review Understanding the space weather Distrubed geomagnetic conditions monitored by SUPARCO 9 10 Transit of Venus Events of the Month Date Time Event\Direction 03 Jul After Sunset Full Moon\ East 15 Jul Before Sunrise After Sunset Pleisdes,Moon, Jupiter, Venus\ East New Moon\ West 24 Jul After Sunset Moon, Mars, Saturn and Spica\ West 28 Jul After Sunset Delta Aquarids Meteor Shower\ East 20 Jul Halo and Sun dog Sun dogs: Another atmospheric phenomenon that is related to haloes is called sun dogs. Sun dogs or parhelia are atmospheric phenomena that create bright spots of light in the sky, often on a luminous ring or halo on either side of the sun. When light refracts through flat horizontal ice crystals, you might see bright spots of light along the right and left sides of a halo. Sundogs may also appear as a colored patch of light to the left or right of the sun. They can be seen SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication Page II anywhere in the world during any season, but they are not always obvious or bright. Sundogs are best seen and are most conspicuous when the sun is low. Light Pillars: Sun Pillars appear most often at sunrise and sunset as a vertical shaft of light extending upward or downward from the sun. They are formed by reflection of sunlight through ice crystals. Pillars also form when hexagonal plate like ice crystals fall with their flat bases oriented horizontally. As they fall, they tilt from side to side and reflect the light off the tipped surfaces of the crystals. A bright area is then produced above or below the sun. Mirage Crepuscular Rays: Crepuscular rays are rays of sunlight that appear to radiate from a single point in the sky. These rays, which stream through gaps in clouds or between other objects, are columns of sunlit air separated by darker cloud shadowed regions. The name comes from their frequent occurrences during crepuscular hours (those around dawn and dusk), when the contrasts between light and dark are the most obvious. Carpesculated Rays Light Pillar Mirage: Mirage are formed when light is bent as it passes through the atmosphere having varying densities. When the sun heats the earth’s surface, the air closer to the ground is warmer and less dense than layers of air higher in the atmosphere. As light travels from a less dense medium to a denser medium at an angle, the light is bent toward the normal. As light travels from a dense medium to a less dense medium at an angle, the light is bent away from the normal. We see mirages as shimmering or watery spots on hot surfaces, inverted reflections of distant objects, and other objects appear taller than they really are. SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication Glory: A common optical phenomenon involving water droplets is the glory. A glory is an optical phenomenon, appearing much like an iconic Saint's halo about the head of the observer, produced by light backscattered (a combination of diffraction, reflection and refraction) towards its source by a cloud of uniformly-sized water droplets. A glory has multiple colored rings, with red color on the outermost ring and blue/violet colors on the innermost ring. The angular distance is much smaller than a rainbow, ranging between 5° and 20°, depending on the size of the droplets. The glory can only be seen when the observer is directly between the sun and cloud of refracting water droplets. Hence, it is commonly Page III observed while airborne. Glory can also be seen from mountains and tall buildings, when there are clouds or fog below the level of the observer, or on days with ground fog. Because rainbows are light and because light rays strike everyone's eyes a little differently, the rainbow one see will be a little different from the one someone else sees. Auroras: An aurora is a natural light display in the sky, particularly in the Polar Regions, caused by the collision of charged particles directed by the Earth's magnetic field. An aurora is usually observed at night and typically occurs in the ionosphere. Glory Rainbows: A rainbow is visible light broken into it’s components what we see as seven colors: red, orange, yellow, green, blue, indigo and violet. They always appear in the same order, with red on top and violet on the bottom, in a main rainbow. In a secondary rainbow, they appear in the opposite order. Rainbows are light refraction phenomenon. One can't touch them. One can't reach around behind them. They exist only in the eyes and sometimes the photographs of the people who see them. Three things must happen for one to see a rainbow's colors. First, the sun must be shining. Second, the sun must be behind one, and third, there must be water drops in the air in front of one. Sunlight shines into the water drops, which act as tiny prisms that bend or "refract" the light and separate it into colors. Each drop reflects only one color of light, so there must be many water drops to make a full rainbow. One will see the brightest rainbows when the water drops are large, usually right after a rain shower. Auroras Meteors Showers: Meteor showers are one of the major night sky phenomena, occurring in different time of months throughout the year. Following table illustrates the occurrence and the source of generation of meteor showers, The name of each meteor shower is taken from its appearance in the respective constellation in the sky. For example Orionids has its radiant point (from where the meteors appear to come) lies in Orion constellation. Rainbow SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication Page IV White Dwarf Stars The degenerated core of a dead star is called white dwarf. It is very dense and possesses mass comparable to that of the Sun and volume to that of the Earth. One tea spoon of the white dwarf material weighs about 6500kg or over 7 metric tons. It emits faint white light due to stored thermal energy. Formation of White dwarf: White dwarfs are very faint small in size and hard to detect. Only a few ones are known. We find most of them as members of binary systems. Even the brightest star, Sirius, has a white dwarf companion, named as Sirius B(shown in figure below). In January 2009, the project of “Research Consortium on Nearby Stars” discovered eight white dwarfs among the hundreds star systems nearest the Sirius B Stars in their red giant phase start to burn helium by triple alpha nuclear process and convert helium into carbon and oxygen. The core of star shrinks further due to gravitational force when helium fuel is exhausted. Those stars which do not have enough mass to fuse carbon and oxygen end their lives in the form of a beautiful planetary nebula with central degenerated core (white dwarf). White dwarf is unable to create internal pressure (e.g. SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication release of energy from fusion, as it has ceased), gravity compacts the matter inward until the electrons that compose a white dwarf's atoms, is smashed together. In normal circumstances, identical electrons (those with the same "spin") are not allowed to occupy the same energy level. Since there are only two ways an electron can spin, only two electrons can occupy a single energy level. This is what's known in physics as the Pauli’s Exclusion Principle. In a normal gas, this isn't a problem because there aren't enough electrons floating around to fill up all the energy levels completely. But in a white dwarf, the density is much higher, and all of the electrons are much closer together. This is referred to as a "degenerate" gas, meaning that all the energy levels in its atoms are filled up with electrons. For gravity to compress the white dwarf further, it must force electrons where they cannot go. Once a star is degenerate, gravity cannot compress it anymore, because quantum mechanics dictates that there is no more available space to be taken up. So our white dwarf survives, not by internal fusion, but by quantum mechanical principles that prevent its complete collapse. Degenerate matter has other unusual property. For example, the more massive a white dwarf is, the smaller it is. This is because the more mass a white dwarf has, the more its electrons must squeeze together to maintain enough outward pressure to support the extra mass. However, there is a limit on the amount of mass a white dwarf can have. Subrahmanyan Chandrasekhar discovered this limit to be 1.4 times the mass of the Sun. This is appropriately known as the "Chandrasekhar limit." No white dwarf beyond this limit has yet been observed. Page V Software Review The Fate of white dwarf: White dwarf stars have all the energy they will ever have. Over billions of years, they will gradually radiate the energy stored in the motion of their hot positive ions (carbon and oxygen nuclei). We can call them “retired stars,” since they are spending their life savings of stored energy; they are not undergoing nuclear fusion process as the normal stars do. White dwarfs eventually become so cool and dim that they can no longer be seen, at least not easily and these objects are known as “black dwarfs” but there is no clear boundary between a white dwarf and a black dwarf. White dwarf can accrete mass from companion in binary system and can cause a catastrophic explosion of the universe called “Type 1A Supenova”. In other case merger of two white dwarfs can cause the same explosion. Type 1a supernovae are used by astrophysicists as standard candles to measure relative distances between galaxies. Cartes du Ciel is a free planetarium program developed by Patrick Chevalley, the author of “Virtual Moon Atlas” (reviewed in January 2012 issue). This software is available for Linux, Mac OS X and Windows. This program enables one to draw sky charts, making use of the data in 16 catalogs of stars and nebulae. In addition, the position of planets, asteroids and comets are shown. The purpose of this program is to prepare different sky maps for a particular observation. A large number of parameters help to choose specifically or automatically which catalogs to use, the color and the dimension of stars and nebulae, the representation of planets, the display of labels and coordinate grids, the superposition of pictures, the condition of visibility and more. All these features make this celestial atlas more complete than a conventional planetarium. Merger of two white dwarfs causing type 1a supernova SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication The software is comparable to other commercially planetarium programs (Skymap pro) that range around 70 dollars whereas Cartes Du Ciel is absolutely free to download and spaced around 15 MB. There are 15 supported catalogs, including Tycho and the Guide Star Catalog, though only the Bright Star Catalog and SKY2000 are included in the base distribution. This is a reasonable approach since some catalogs are huge, and it does keep the distribution size down to around 15MB. But even with the two small catalogs, you can view 300,000 stars down to magnitude 9. Page VI Sky this Month July 1, 2012 – Aldebran, Jupiter, Venus and Pleiades Before the dawn timings of July 1, the two brightest planets, Venus and Jupiter, will be in company with a red giant star, Aldebran, and an open cluster of nearly 200 stars, Pleiades. This can be viewed in Eastward direction early in the morning. to the clear sky. Clouds and haze may cause problems in viewing the new moon. Position of the moon at the time of sunset in Karachi July 24, 2012 – Moon, Mars, Saturn and Spica The Last quarter moon will be showing a tetrahedral along with Mars, Saturn and a fairly bright bluish white star of constellation Virgin , Spaica in the sky. The view would be visible in the Westward direction July 15, 2012 –Pleiades, Moon, Jupiter, Venus and Aldebran The situation will be observed 2 week later changes as on July 15 the waning moon will now have its proximity with Jupiter which has attained some altitude during this period. Venus and Aldebran would also be lying fairly above the horizon after two weeks. Same timings and direction would be implied as of July 1. July, 28, 29, 2012- Meteor Shower The South Delta Aquarids can produce about 20 meteors per hour. Radiant point for these meteors is in the constellation Aquarius. July 20, 2012 - New Moon Chance of new moon visibility in the sky would be favorable although the visibility would be subjected to the clear sky. Clouds and Position of the moonhaze at the timemay of sunsetcause in Peshawar problems in viewing the new moon. SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication Page VII Web Review Book Review Supported by NASA, The NSSDC Photo Gallery is intended to fulfill two different purposes. The first of these is to provide access to some of the more popular NASA images available to the public. NSSDC fills hundreds of requests per year for thousands of photographs, but many of the same images are requested time and again. Many of these are provided in the Photo Gallery. Astronomy For Dummies tells what you need to know to make sense of the world above us. Written by one The second purpose of the Photo Gallery is to of the most well-known astronomers in the world, this provide examples of images produced from CD-ROM fun, fact-filled, and accessible guide fills you in on the data. The images presented in the Photo Gallery basic principles of astronomy and tells you how to: have a number of different sources, primarily NASA missions, however. They are generally organized by •Identify planets and stars object and/or phenomenon on separate pages. The •Explore our solar system, the Milky Way, and source of the images as well as the processing beyond involved in producing the image have been included •Understand the Big Bang, quasars, antimatter, black wherever possible. Photo captions for some images holes, and more are also available. •Join the Search for Extraterrestrial Intelligence The photo gallery list images by the following topics, Planetary Astronomical Objects Others; including Sun and Space crafts And indexes which includes Hubble space telescope, Galileo and Voyager. The images are shown on the pages as reduced versions ("thumbnails") of the full images. Most of the full images are in JPEG format. Because of the large number of thumbnails on some pages, you may wish to turn off automatic loading of images if you are accessing these pages via a slower dial-up connection. To retrieve the full images (for on-line viewing and/or to save them), select the reduced version. A limited number of the images in the Photo Gallery are also available on the FTP site in TIFF format in a high-resolution form. Links appear when this option is also available. SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication (SETI) •Get the most out of planetarium visits •Make more sense out of space missions From asteroids to black holes, quasars to white dwarfs, Astronomy For Dummies takes you on a grand tour of the universe. Featuring star maps, charts, gorgeous full-color photographs, and easy-to-follow explanations it gives you a leg up on the basic science of the universe. Topics covered include: •Observing the night sky, with and without optics •Selecting binoculars and telescopes and positioning yourself for the best view •Meteors, comets, and man-made moons •Touring our solar system and becoming familiar with the planets, asteroids, and near earth objects •Our Sun, stars, galaxies, black holes and quasars •SETI and planets revolving around other suns •Dark matter and antimatter •The Big Bang and the evolutions of the universe Page VIII Understanding Space Weather The objective of this article is to develop an understanding of space weather for readers with less or no scientific knowledge. The difference between tropospheric and space weather has been addressed in the article. References have been given at the end for further reading. Weather: All of us are familiar with the term 'weather' which presents the state of atmosphere at a particular location on Earth at a given time. The weather we come across daily gives the condition of troposphere (which is the lowest region of the atmosphere of Earth having an average height of 18 km). Any phenomenon taking place in this region of the Earth's atmosphere alters the weather. At the time of writing these lines the weather of Karachi from a weather website http://www.wunderground.com/ was observed as shown in the Figure 1. It is clear from the figure that weather of Karachi on the given day is partly cloudy with a temperature of 34 C and a wind speed of 30km/hr. The figure informs about the sunrise/set times and phase of moon also. Additionally, a 5 day forecast has been presented mentioning the temperature and condition of the weather at Karachi. A person seeking information about the weather can easily understand the atmospheric conditions by looking at one such forecast as presented. Weather of Karachi on 24-May-2012 at 1230PST Space Weather: On the other hand, Space Weather is a concept which describes the changes in the Sun and their impacts on the environment of Earth. The term space weather was apparently coined in 1972 by a memo of US Air Force, whereas the common use of the term started in 1990s. Definitions: There are various ways of defining the space weather, some of the definitions from different sources have been mentioned below. "The time varying conditions in the near-Earth space environment that may affect space-borne or ground-based technological systems and may endanger human health or life are referred to as space weather." (Singh, 2010) This definition talks about the effects of space weather on the Earth environment and technology. "Space weather is a consequence of the behaviour of the Sun, the nature of Earth's magnetic field and atmosphere and our location in the solar system." (Goodman, 2004) It is clear from the definition above that space weather is a result of solar behaviour. Any variation or disturbance in Sun can alter the space weather which can be experienced in the solar system. Below is a more comprehensive definition of the term which combines both the above mentioned definitions. "The term space weather is defined as the conditions on the Sun and in the solar wind, Earth’s magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and endanger human life or health." (Eastwood, 2008) References: Eastwood, J. P. [2008], "The science of space weather", Philosophical Transactions of The Royal Society A, Vol 366, pp 4489-4500 Goodman, J. M. [2005], "Space Weather & Telecommunications", Springer Singh, A. K., Siingh, D., Singh, R. P. [2010]. "Space Weather: Physics, Effects and Predictability", Surveys in Geophysics, Vol 31, pp 581-638 SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication Page IX Disturbed storm condition monitored by SUPARCO The space weather monitoring facilities at SUPARCO recorded geomagnetic disturbances during 16-18 June, 2012 caused by 02 Coronal Mass Ejections which erupted on the June 13th and June 14th, 2012. The CME’s shockwave hit the Earth’s Magnetic Field on the 16th June, 2012 causing strong variation in the geomagnetic field as shown by the Magnetograms of the Abdus Salam Geomagnetic Observatory and the Islamabad Geomagnetic Observatory below. The magnetograms of the Abdus Salam Observatory show disturbed geomagnetic variation during 16-18 July, 2012 The magnetograms of the Islamabad Geomagnetic Observatory show disturbed geomagnetic variation during 16-18 The picture on the right shows the active region on the Sun which caused a long duration M-class flares for two consecutive days in a row which hurled 02 CMEs one after the other towards Earth causing the Geomagnetic Storms recorded in the Magnetograms above. Ghulam Murtaza General Manager Gulzar-e-Hijri SUPARCO Road Sector 28, SUPARCO, Karachi, Pakistan Tel: 021-34690765-74 Fax 021-34690795 Email: [email protected] Image taken by NASA's Solar Dynamics Observatory (SDO) showing the active region emitting high energy solar radiation SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication Page X Transit of Venus June 06, 2012 Transit of Venus 2012 will remain one of the memorable astronomical event ever observed. SUPARCO was preparing two weeks prior to the event . A setup of a small hut at the rooftop of the building with all necessary connections was made. The telescope used was an 8 inch SCT with Badeer and H alpha filter for our observation of the transit. The first two contacts of the transit were not observable as the Sun was below the horizon in Karachi. It was feared that morning of June 06 could be cloudy and there would be no chances of observing the event from Karachi. The sunset timing was 05:42 AM local time but it was very hazy in the morning. The first time when the sun came into a clearer view was at 07:15 AM. Prime focus method was used for observing the transit. A DSLR was directly attached with the telescope and the transit was visible in the display monitor of camera so that multiple visitors could view the event at a time. Around 100 employees of SUPARCO witnessed that historical event. Track of Venus on the solar disk during transit June 06, 2012 Contact Information Links to website: More Image Video of transit of Venus 2012 can be seen at the official website of SUPARCO by following the link http://www.suparco.gov.pk/pages/astronomy-bulletin.asp Rizla Zareen General Manager Gulzar-e-Hijri SUPARCO Road Sector 28, SUPARCO, Karachi, Pakistan Tel: 021-34690765-74 Fax 021-34690795 Email: [email protected] SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication This bulliten can be downloaded from the official website of SUPARCO