अन्तरिक्ष बिज्ञान र प्रबिधि (Astronomy Science and Technology)

High-mass stars are important because they are responsible for much of the energy pumped into our galaxy over its lifetime. Unfortunately, these stars are poorly understood because they are often found relatively far away and can be obscured by gas and dust. The star cluster NGC 281 is an exception to this rule. It is located about 9,200 light years from Earth and, remarkably, almost 1,000 light years above the plane of the Galaxy, giving astronomers a nearly unfettered view of the star formation within it. NGC 281 is known informally as the "Pacman Nebula" because of its appearance in optical images. In optical images the "mouth" of the Pacman character appears dark because of obscuration by dust and gas, but in the infrared Spitzer image the dust in this region glows brightly.

This image is from a 2008 cold flow test campaign conducted at NASA's Marshall Space Flight Center for the J-2X engine program. NASA continues to test the J-2X engine and conducted a 40-second test of the rocket engine Sept. 28, the most recent in a series of tests of the next-generation engine selected as part of the Space Launch System architecture that will once again carry humans into deep space. It was a test at the 99 percent power level to gain a better understanding of start and shutdown systems as well as modifications that had been made from previous test firing results.

Tadpole Nebula This infrared image from NASA's Wide-field Infrared Survey Explorer, or WISE, showcases the Tadpole Nebula, a star-forming hub in the Auriga constellation about 12,000 light-years from Earth. As WISE scanned the sky, capturing this mosaic of stitched-together frames, it happened to catch an asteroid in our solar system passing by. The asteroid, called 1719 Jens, left tracks across the image. A second asteroid was also observed cruising by. But that's not all that WISE caught in this busy image -- two natural satellites orbiting above WISE streak through the image, appearing as faint green trails. This Tadpole region is chock full of stars as young as only a million years old -- infants in stellar terms -- and masses over 10 times that of our sun. It is called the Tadpole nebula because the masses of hot, young stars are blasting out ultraviolet radiation that has etched the gas into two tadpole-shaped pillars, called Sim 129 and Sim 130. These

This artist's concept shows a glowing patch of ultraviolet light near Saturn's north pole that occurs at the "footprint" of the magnetic connection between Saturn and its moon Enceladus. The footprint and magnetic field lines are not visible to the naked eye, but were detected by the ultraviolet imaging spectrograph and the fields and particles instruments on NASA's Cassini spacecraft. The footprint, newly discovered by Cassini, marks the presence of an electrical circuit that connects Saturn with Enceladus and accelerates electrons and ions along the magnetic field lines. In this image, the footprint is in the white box marked on Saturn, with the magnetic field lines in white and purple. A larger white square above Enceladus shows a cross-section of the magnetic field line between the moon and the planet. This pattern of energetic protons was detected by Cassini's magnetospheric imaging instrument (MIMI) on Aug. 11, 2008. The patch near S

  Using the Hubble Space Telescope, astronomers are witnessing the unprecedented transition of a supernova to a supernova remnant, where light from an exploding star in a neighboring galaxy, the Large Magellanic Cloud, reached Earth in February 1987. Named Supernova 1987A, it was the closest supernova explosion witnessed in almost 400 years. The supernova's close proximity to Earth allows astronomers to study it in detail as it evolves. Now, the supernova debris, which has faded over the years, is brightening. This means that a different power source has begun to light the debris. The debris of SN 1987A is beginning to impact the surrounding ring, creating powerful shock waves that generate X-rays observed with NASA's Chandra X-ray Observatory. Those X-rays are illuminating the supernova debris and shock heating is making it glow in visible light. Since its launch in 1990, the Hubble telescope has provided a continuous record of the changes in SN 1987A.

Various stages of the merger of two neutron stars are shown in this simulation sequence; the images cover a period of about one-hundredth of a second. Once the stars collide, material is squeezed out between the stars and gets stripped off from tidal tails. In the material ejected, a multitude of nuclear reactions takes place, producing heavy elements. Photo by S. Goriely, A. Bauswein, and H.-T. Janka (MPA) The cosmic site where the heaviest chemical elements such as lead or gold are formed has likely been identified: Ejected matter from neutron stars merging in a violent collision provides ideal conditions. In detailed numerical simulations, scientists of the Max Planck Institute for Astrophysics (MPA) in Garching, Germany, and affiliated to the Excellence Cluster Universe and of the Free University of Brussels (ULB) in Belgium have verified that the relevant reactions of atomic nuclei do take place in this environment, producing the heaviest elemen

The "invisible" world Kepler-19c, seen in the foreground of this artist's conception, was discovered solely through its gravitational influence on the companion world Kepler-19b — the dot crossing the star's face. Kepler-19b is slightly more than twice the diamter of Earth — probably a "mini-Neptune." Nothing is known about Kepler-19c other than that it exists. Photo by David A. Aguilar (CfA) Usually, running five minutes late is a bad thing because you might lose your dinner reservation or miss out on tickets to the latest show. But when a planet runs 5 minutes late, astronomers get excited because it suggests that another world is nearby. NASA’s Kepler spacecraft has spotted a planet that alternately runs late and early in its orbit because a second, “invisible” world is tugging on it. This is the first definite detection of a previously unknown planet using this method. No other technique could have found the unseen co

Construction on the first space-bound Orion Multipurpose Crew Module began with the first weld at the Michoud Assembly Facility on Sept. 9. 2011. This capsule will be used during Orion's first test flight in space.   After welding is completed at Michoud, the Orion spacecraft orbital test article will be shipped to NASA’s Kennedy Space Center, where the heat shield will be installed. At Kennedy, it will undergo final assembly and checkout operations for eventual flight.

 Fire and smoke light up a blue sky as a United Launch Alliance Delta II Heavy rocket propels NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission into space. Liftoff from Space Launch Complex 17B on Cape Canaveral Air Force Station in Florida was at 9:08:52 EDT Sept.10. The spacecraft are embarking on a three-month journey to reach the moon. GRAIL will fly twin spacecraft in tandem around the moon to precisely measure and map variations in the moon's gravitational field. The mission will provide the most accurate global gravity field to date for any planet, including Earth. This detailed information will reveal differences in the density of the moon's crust and mantle and will help answer fundamental questions about the moon's internal structure, thermal evolution, and history of collisions with asteroids. The aim is to map the moon's gravity field so completely that future moon vehicles can safely navigate anywhere on the moon'

NASA's Viking Project found a place in history when it became the first U.S. mission to land a spacecraft successfully on the surface of Mars. Two identical spacecraft, each consisting of a lander and an orbiter, were built. Each orbiter-lander pair flew together and entered Mars orbit; the landers then separated and descended to the planet's surface. Viking 2 launched 36 years ago today on Sept. 9, 1975. This photo shows a test version of the landers in the original "Mars Yard" built at NASA's Jet Propulsion Laboratory in 1975. The Viking 2 lander settled down at Utopia Planitia on Sept. 3, 1976, while the Viking 1 Lander touched down on the western slope of Chryse Planitia (the Plains of Gold) on July 20, 1976. Besides taking photographs and collecting other science data on the Red Planet's surface, the two landers conducted three biology experiments designed to look for possible signs of life. These experiments discovered unexpected

Solar Dynamics Observatory data indicates that radiation from solar flares continues for up to 5 hours beyond the peak event, with the total energy sometimes being greater than that of the initial flare. By NASA's Goddard Space Flight Center, Greenbelt, Maryland — Published: September 8, 2011 While observing a May 2010 solar flare with its multiwavelength vision, the Solar Dynamics Observatory recorded data indicating that some other wavelengths of light weren't behaving in sync with the X-rays, but peaked at other times. Photo by NASA/SDO/Tom Woods The Sun's surface dances. Giant loops of magnetized solar material burst up, twist, and fall back down. Some erupt, shooting radiation flares and particles out into space. Forced to observe this dance from afar, scientists use all the tools at their disposal to look for patterns and connections to discover what causes these great explosions. Mapping these patterns could help scientists

Solar System Montage Image courtesy NASA This montage of Voyager spacecraft pictures shows the eight planets, plus four of Jupiter's moons, sprawled against the backdrop of the Rosette Nebula and on the horizon of Earth's moon. In addition to the planets and moons seen in this simulated photo, our solar system contains a star, asteroids and comets, and dwarf planets such as Pluto.

X-Ray Jet Illustration courtesy NASA/CXC/M. Weiss An artist's rendering, made using data collected by the orbiting Chandra X-ray Observatory, shows a quasar galaxy with a jet of high-energy particles extending more than 100,000 light-years from the supermassive black hole at its center. The object, located 12 billion light-years from Earth, is the most distant such jet ever detected. These quasar jets are formed when electrons emitted from a black hole impact with cosmic background radiation left by the big bang, giving astronomers clues about the conditions in the early universe.

    तारा को अर्थ हुन्छ नक्षत्र। किन्तु प्रयोगका अनुसार यसका भिन्न अर्थ पनि हुन सक्छन्। रातमा आकाशमा धेरै पिण्ड चम्किरहन्छन्, यिनमाबाट अधिकतर पिण्ड सधैं पूरबको दिशाबाट उठ्दछन् र एक निश्चित गति प्राप्त गर्दछन् र पश्चिमको दिशामा अस्त हुन्छन्। यी पिण्डहरुको आपसमा एक अर्काका सापेक्ष पनि कुनै परिवर्तन हुँदैन। यी पिण्डहरुलाई तारा (Star) भनिएको छ।मा केहि यस्ता पनि पिण्ड छन् जो बाकी पिण्डका सापेक्षमा कहिले अघि जान्थे र कहिले पछि - अथवा कि ती घुमक्कड़ थिए। Planet एक लैटिनको शब्द छ जसको अर्थ यता-उता घूमने वाला छ। यस कारण यी पिण्डहरुको नाम Planet र नेपालीमा ग्रह राखिएको छ। हाम्रो लागि आकाशमा सबैभन्दा चम्किला पिण्ड सूर्य छ, फिर चन्द्रमा र त्यसको पछि रातका ताराहरु वा ग्रह। ताराहरु स्वयंमा एक सूर्य छन्। ज्यादातर, हाम्रो सूर्यबाट ठूला र चमकिला, तर यति टाड़ा छन् कि तिनको प्रकाश हाम्रो छेउ आउँदै आउँदै धेरै क्षीण भइहाल्छ यस कारण दिनमा देखिंदैनन् तर रातमा देखिन्छन्। केहि प्रसिद्ध ताराहरु यस प्रकार छन्: ध्रुव तारा व्याध तारा मित्रक तारा ग्रह र चन्द्रमा, सूर्य छैनन्। यो आफ्नो प्रकाशमा

सौर्यमण्डल एक खगोलिय प्रणाली हो, जसको केन्द्रमा रहेको तारालाई ग्रहहरू तथा उल्का पिण्डहरूले परिक्रमा गर्दछन। सबै भन्दा प्रशिद्ध सौर्यमण्डल त्यो हो जहाँ मानवहरू रहेका छन, पृथ्वी रहेको छ। पृथ्वीले सूर्यको वरिपरि एक अण्डाकार कक्ष, जुन लगभग चक्राकार छ, मा परिक्रमा गर्दछ। अरु ग्रहहरूले पनि सूर्यको वरिपरि अण्डाकार कक्षमा परिक्रमा गर्दछन। ग्रह सूर्यको वरिपरि घुम्ने सबैभन्दा ठुला पिण्डहरूलाई ग्रह भनिन्छ। दुरविनका सहायताले गहन खोज गरि ग्रहहरू पत्ता लगाउन मानिसहरूलाई कयौँ वर्ष लागेको थियो। कुनै ठुला ग्रहहरू पत्ता नलागेको धेरै वर्ष भईसक्यो, तर साना पिण्डहरू भने हरेक वर्ष धेरै पत्ता लाग्ने गरेको छ। यम (प्लुटो) अब ग्रह रहेन यमलाई ग्रह भनिन थालेको करिब सय वर्ष भईसक्यो। सन २००६ मा खगोलशास्त्रीहरूले यसको सानो आकारका कारण यसलाई ग्रहबाट अबोन्नति गरि फुच्चेग्रह वा सानो-ग्रहको दर्जा दिए। यसो गर्नाको अर्को कारण यसको कक्ष हो, जुन अरु ८ ग्रहहरूको भन्दा निक्कै भिन्न छ। हाल यम, सेरेस र एरिस समेतलाई फुच्चे-ग्रह वा सानो-ग्रह भनिन्छ। सौर्यमण्डलिय पिण्डहरूको क्रम हाम्रो सौर्यम

ग्रह, तारा, सौर्यमण्डल, तारापुञ्ज र अन्य दृस्य र अदृस्य खगोलिय पिण्डहरुको अध्ययन् र अवलोकन गर्ने विधालाई खगोलशास्त्र भनिन्छ। खगोलशास्त्र मानवजातिको एक सारै पुरानो विज्ञान हो। यसको सुरुवात लिखित इतिहास भन्दा धेरै पुरानो छ। नेपालबाट खगोल समाचार २००९ को Total Solar Eclipse नेपालको पूर्वि भागबाट देखिने छ। यसको लागी गाईघाट, उदयपुर एक उचित ठाँऊ हो। नेपालमा खगोलशास्त्र खगोलशास्त्र को शुरुवात मानव इतिहास को शुरुवात सगँसगैँ भएको मानिन्छ। प्राचीन कालमा मानिसले रात को समयमा अन्य जनावर सुतिरहेको बेला शिकार गर्न चन्द्रमा को उज्यालो प्रयोग गर्दथे। र दिन को गिन्ती राखि कहिले पूर्णिमा आउछ पत्तो पाउदथे। पछि किसान हरुले बाली लगाउने र काट्ने समय को किटान आकाशीय पिण्डको स्थिति हेरेर गर्न थाले। अझ पछि व्यापारी (traders) तथा नाविकहरूले दिशा पत्तो लगाउन आकाशीय पिण्डको स्थिति नै प्रयोग गर्नथाले। यसरी युगौँ देखी मानिसले आफ्नो जिवन धान्न खगोल विज्ञान को प्रयोग गरिरहेका छन्। आकाशीय अवलोकण गर्दा आकाशीय पिण्डहरू को गति सामयिक (periodic) हुने

Godfrey Kneller's 1689 portrait of Isaac Newton (age 46) जन्म 4 जनवरी 1643 [OS: 25 December 1642] Woolsthorpe-by-Colsterworth Lincolnshire, England मृत्यु 31 मार्च 1727 (84वर्ष ) [OS: 20 March 1726] 0.3em Kensington, Middlesex, England वासस्थान इङ्गल्यण्ड राष्ट्रीयता अङ्ग्रेजी जातियता Caucasian क्षेत्र physics, mathematics, astronomy, natural philosophy, alchemy, Christian theology कार्यस्थल University of Cambridge Royal Society Royal Mint शिक्षा Trinity College, Cambridge शैक्षणीक सलाहकार Isaac Barrow Benjamin Pulleyn उल्लेखनीय शिष्यहरु Roger Cotes William Whiston प्रसिद्धि Newtonian mechanics Universal gravitation Infinitesimal calculus Optics Binomial series Newton's method Philosophiæ Naturalis Principia Mathematica प्रभाव Henry More Polish Brethren प्रभावित Nicolas Fatio de Duillier John Keill हस्ताक्षर टिप्पणी His mother was Hannah Ayscough. His half-niece was Catherine

The six-member Expedition 28 crew. Image Credit: NASA Andrey Borisenko commands the Expedition 28 crew which will continue to support research into the effects of microgravity on the human body, biology, physics and materials. Borisenko and Flight Engineers Ron Garan and Alexander Samokutyaev docked to the Poisk module April 6 aboard the Soyuz TMA-21 spacecraft. Russian cosmonaut and Soyuz Commander Sergei Volkov, NASA Flight Engineer Mike Fossum and Japan Aerospace Exploration Agency Flight Engineer Satoshi Furukawa launched from the Baikonur Cosmodrome on June 7 aboard the Soyuz TMA-02M spacecraft. The trio joined the Expedition 28 crew as flight engineers after docking their Soyuz to the Rassvet module on the Russian segment of the station on June 9. Expedition 27 ended and Expedition 28 began while space shuttle Endeavour was docked to the International Space Station during the STS-134 mission. Endeavour and its six astronauts delivered the Alpha Magnetic Spe

NuSTAR will be the first focusing high energy X-ray mission, opening the hard X-ray sky for sensitive study for the first time. NuSTAR will search for black holes, map supernova explosions, and study the most extreme active galaxies.

NASA's GRAIL twin spacecraft await launch atop a United Launch Alliance Delta II rocket at Cape Canaveral Air Force Station, Fla. Image credit: NASA/JPL-Caltech/United Launch Alliance, Thom Baur   Stages of pre-launch preparations of NASA's twin GRAIL spacecraft in Florida. Image credit: NASA/JPL-Caltech Status update: -- NASA's twin GRAIL spacecraft have successfully separated from the upper stage of their Delta II rocket. They are on their way to the moon. -- The rocket nose cone, or fairing, carrying NASA's GRAIL spacecraft has been jettisoned, as planned. -- NASA's GRAIL spacecraft, headed to the moon, have lifted off from Cape Canaveral, Fla., aboard a United Launch Alliance Delta II rocket. --> -- Because of upper-level winds, the launch of NASA's GRAIL mission has been delayed to Friday, Sept. 9. There are two launch opportunities: at 5:33:25 a.m. PDT (8:33:25 a.m. EDT) and 6:12:31 a.m. PDT (9:12:31 a.m.

International Space Station March 2009 spacewalk by shuttle astronaut Joseph Acaba with Discovery and Kibo in the background.

Artist's concept of the Mars Reconnaissance Orbiter. Image credit: NASA/JPL Mission Status Report PASADENA, Calif. -- Operators of NASA's Mars Reconnaissance Orbiter are resuming use of the mission's highest resolution camera following a second precautionary shutdown in two weeks. The High Resolution Imaging Science Experiment (HiRISE) instrument powered off on Aug. 27 and again on Sept. 6. In each case, commanding for an observation was not properly received by the memory module controlling one of the instrument's 14 electronic detectors (CCDs, or charge-coupled devices). Between those two incidents, the camera successfully resumed observations for five days using its other 13 detectors. The second entry into the power-off, thermally protected mode occurred during an attempt to add use of the 14th detector. The camera is resuming observations with 13 detectors today while plans are developed for other diagnostic tests. The detecto

NASA's GRAIL twin spacecraft await launch atop a United Launch Alliance Delta II rocket at Cape Canaveral Air Force Station, Fla.

Mars in 1980 as seen by the Viking 1 Orbiter Designations Pronunciation Listen ˈ m ɑr z / Adjective Martian Orbital characteristics Epoch J2000 Aphelion 249,209,300 km 1.665 861 AU Perihelion 206,669,000 km 1.381 497 AU Semi-major axis 227,939,100 km 1.523 679 AU Eccentricity 0.093 315 परिभ्रमण अवधि 686.971 days 1.8808 Julian years 668.5991 sols परिभ्रमण अवधि 779.96 days 2.135 Julian years परिभ्रमण गति 24.077 km/s Mean anomaly 19.3564° Inclination 1.850° to ecliptic 5.65° to Sun's equator 1.67° to invariable planet Longitude of ascending node 49.562° Argument of perihelion 286.537° उपग्रह 2 Physical characteristics भूमध्यरेखीय अर्धब्यास 3,396.2 ± 0.1 km 0.533 Earths ध्रुवीय अर्धब्यास 3,376.2 ± 0.1 km 0.531 Earths Flattening 0.005 89 ± 0.000 15 सतहको क्षेत्रफल 144,798,500 km 2 0.284 Earths आयतन 1.6318 × 10 ११  km 3 0.151 Earths पिण्ड 6.4185 × 10 २३  kg 0.107 Earths

ब्रह्माण्ड हबल दूरबीनले खिंचेको ब्रह्माण्डको एक भागको चित्र ब्रह्माण्ड शव्दले ती सम्पूर्ण कुराहरुको बोध गराउँछ जस अन्तर्गत प्रकृति, अन्तरीक्ष र समय, पदार्थ (all forms of matter)र उर्जा, भौतिक नियम र सृष्टि सञ्चालन आदि चलेकोछ। ब्रह्माण्डभित्र सम्पूर्ण आकाश गंगा(galaxy), तारा, ग्रह, उपग्रह आदि आदि अटाएकाछन्। ब्रह्माण्ड शव्दलाई सबै कुरा अटाउने भनेर परिभाषित गरिएकोछ। परन्तु अर्को शव्दमा भन्दा "ब्रह्माण्ड" जसलाई अंग्रेजीमा "Universe" भनिन्छ, धेरैको विचार अनुसार महाब्रह्माण्ड(Multiverse)मा फैलिंदो स्थिति जसबाट चुँडिएको भागलाई ब्रह्माण्ड भनेर भनिन्छ। धेरैवटा ब्रह्माण्ड(Universes)को समूहलाई महाब्रह्माण्ड(Multiverse) भनिन्छ। उदाहरणको निम्ति संसारका धेरैवटा परिकल्पना अनुसार नयाँ ब्रह्माण्डहरु निर्धारित मापको आधारमा सृष्टि हुन्छन्। ती ब्रह्माण्डहरु साधरणतया हाम्रो ब्रह्माण्डदेखि अलगिएको विश्वास गरिएको हुँदा व्यवहारिक तौरमा ठिम्याउन असम्भव छ। ब्रह्माण्डका पुराना अंशहरु (जो हामीदेखि धेरै टाडा छन्)को अवलोकनबाट यो तथ्य फेला परेकोछ कि पूरै ब्रह्

अन्तरराष्ट्रीय अन्तरिक्ष स्टेशन अन्तरराष्ट्रीय अन्तरिक्ष स्टेशन ढाँचा:OV द्वारा एस.टी.एस-१२८बाट देखिएको दृश्य ISS इनसिग्निया स्टेशनका आंकडे NSSDC ID: 1998-067A कल साइन: अल्फ़ा चालक दल: ६ प्रक्षेपण: १९९८-२०११ प्रक्षेपण स्थल: KSC एल.सी-३९, बायकोनुर एल.सी-१/५ & एल.सी-८१/२३ द्रव्यमान: 303,663 कि.ग्रा (669,461 पाउंड) लंबाई: ७३ मी. (२४० फ़ी.) चौडाई: १०८.५ मी. (३५६ फ़ी.) रह्ने स्थान: ३५८ मी.³ (१२,६२६ घन फ़ीट) वायुमंडलीय दबाव: १०१.३ कि.पा (२९.९१ इंच-मर्करी) पेरिजी (भू-समीपक): ३४३ कि.मी ऊंचाई (२१३ मील) एपजी (शिरोबिंदु): ३५१ कि.मी ऊंचाई (२१८&nbspमील) कक्षाको झुकाव: ५१.६४१९ डिगरी औसत गति: २७,७४३.8 कि.मी/घंटा (१७,२३९.2 मील/घंटा, ७,७०६.6 मीटर/से.) परिक्रमण काल: ९१ मिनट २८ जुलाई, २००९का आंकडे कनफिगरेशन स्टेशन घटक (एक्स्प्लोडेड दृश्य) अन्तरराष्ट्रीय अन्तरिक्ष स्टेशन अन्तर्राष्ट्रीय अन्तरिक्ष स्टेशन या केन्द्र (संक्षेपमा आईएसएस , अङ्ग्रेजी: International Space Station इंटर्नॅशनल्

कराइना तारामण्डल कराइना खगोलीय गोलाको दक्षिणी भागमा देखिने एक तारामण्डल हो। यो कहिले आरगो नौका तारामण्डलमा शामिल हुन्थ्यो तर अब त्यो तारामण्डल तीन हिस्सामा बाँड़िएकोछ। रातका आसमानको अर्को सबभन्दा चम्किलो तारा, अगस्ति, यसमा शामिल छ। अन्य भाषामा अंग्रेज़ीमा गराइना तारामण्डललाई "करैना कॉन्स्टॅलेशन" (Carina constellation) लेखिन्छ। गराइना लेटिन भाषाको शव्द हो। फ़ारसीमा यसलाई "शाहतख़्ता" ( شاه‌تخته ) र अरबीमा यसलाई "अल-क़ायदा" भनिन्छ - यी दुइटैको अर्थ "आधार" नैं हुन्छ। कराइनामा खगोलीय वस्तुहरु रात्रीका आकाशमा क्षीरमार्ग (हाम्रो आकाशगंगा)को फैलाव यस तारामण्डलबाट गुज्रन्छ यस लागि यसमा धेरै खुल्ला तारागुच्छ हेर्न सकिन्छ। हर साल आकाशमा गराइनाका क्षेत्रमा एटा कैरिनिड्स नामको उल्कापिंडहरुका बौछारहरु देख्न सकिन्छ जो सबभन्दा अधिक जनवरी २१ को छेउछाउमा देखिन्छ।

कुनै ताराहरुको चम्किलोपन त्यसको आफ्नो भित्री चम्किलोपन, त्यसकी पृथ्वीबाट दूरी र केहि अन्य परिस्थितिहरुमा निर्भर गर्दछ। कुनै ताराहरुका निहित चमकिलापनलाई "निरपेक्ष कान्तिमान" भन्दछन् जबकि पृथ्वीबाट देखिएको त्यसको चम्किलोपन "सापेक्ष कान्तिमान" भन्दछन्। खगोलीय वस्तुहरुको चमकलाई मैग्निट्यूडमा नापिन्छ - ध्यान रहेका यो मैग्निट्यूड जति कम हुन्छ तारा उति नैं अधिक चम्किलो हुन्छ। पृथ्वीबाट देखिने सबभन्दा चम्किला ताराहरु यस प्रकार छन् - क्रमांक कान्तिमान (मैग्निट्यूड) बायर नाम नाम अन्य नाम दूरी (प्र॰व॰) श्रेणी सिम्बाद नाम ० −२६.७४ सूर्य ०.००० ०१६ G2 V १ −१.४६ α CMa व्याध सीरियस (Sirius) ८.६ A1 V सीरियस २ −०.७२ α Car अगस्ति कनोपस (Canopus) ३१० F0 Ia अगस्ति ३ −०.०४ var α Boo स्वाती आर्कट्युरस (Arcturus) ३७ K1.5 III स्वाती ४ −०.०१ α Cen मित्र अल्फ़ा सॅन्टौरी (Alpha Centauri) ४.४ G2 V मित्र ए ५ ०.०३ α Lyr अभिजीत व्नेछ (Vega) २५ A0 V व्नेछ ६ ०.१२ β Ori राजन्य राइजॅल (Rigel) ७७० B8 Iab राइजॅल ७ ०.