Astronomy Definition and 832 Threads

Astronomy (from Greek: ἀστρονομία, literally meaning the science that studies the laws of the stars) is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates outside Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole.Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars. Nowadays, professional astronomy is often said to be the same as astrophysics.Professional astronomy is split into observational and theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects. This data is then analyzed using basic principles of physics. Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. These two fields complement each other. Theoretical astronomy seeks to explain observational results and observations are used to confirm theoretical results.
Astronomy is one of the few sciences in which amateurs play an active role. This is especially true for the discovery and observation of transient events. Amateur astronomers have helped with many important discoveries, such as finding new comets.

View More On Wikipedia.org
  1. parshyaa

    Intro Physics Good physics or astronomy encyclopedia

    Can anyone recommend a good physics or astronomy encyclopedia , I am a 11th grade student
  2. bri7

    Astronomy : Velocity of approach of the Sun's equator

    The sun's rotational period is 25 days at the equator. Given that the radius of the sun is 700,000 km, calculate the max velocity of approach or recession of the Sun's equator as viewed from Earth. Find the max change in wavelength of a spectral line due to the rotation and express it as a...
  3. N

    Stargazing H.E.S.S. gamma ray telescope got an image of the moon

    https://en.m.wikipedia.org/wiki/File:Moon_egret.jpg Can we use better telescopes of this type (ground based gamma rays telescopes) to image the surface and subsurface of a planet with a lot of resolution?
  4. T

    I Why are stars grouped in galaxies?

    I have been thinking at this for a couple of days now: why are stars grouped in the massive collections that we call galaxies? I can assume that in the very early Universe, matter was grouped in these areas, that matter interacted thus resulting in the formation of stars. Then, the...
  5. Timvizz95

    What sparked your love for the natural sciences?

    My names tim, and I am a first year physics student but I've had a love for the natural sciences since I was little. I am 21 years old, and some of my favorite things to do are reading and playing drums. Music has always been a close second to science for me. I hope to get to know some cool...
  6. Z

    Kepler's Third Law and Motion of Two Point Masses

    I'm trying to work through some equations in the paper 'Gravitational Radiation and the Motion of Two Point Masses' (Peters, 1964) but I can't get out the right values 1. Homework Statement For a binary star system with each mass = 1 solar mass, the equations give the results: Separation ~ 10...
  7. S

    Value or what one can do with astronomy or astrophysics education

    Title field did not accept all of title: Value or what one can do with astronomy or astrophysics education What is the real-world, employment value and meaning of a degree in Physics if a student concentrates on astronomy or astrophysics, meaning his employment value? What about such a degree...
  8. Gjmdp

    Studying Is it worth studying Aerospace engineering for Astronomy?

    I want to be an astrophysicist. Physics and Astronomy are my passions, my love. But, I also love Aerospace engineering, and there's no way I can just have this passion as a mere hobby. So, do you think that studying a Master on Aerospace engineering will be worth for being an Astrophysicist...
  9. N

    I If radiowaves are reflected from objects (i.e planets)....

    ...and they can penetrate a bit in the surface, we could image the subsurface right? I do not see the problem... Help please!
  10. S

    Schools Grad School: Distance Learning ? Theoretical physics

    I will be graduating with a bachelors degree in physics in the next year. Most of my professors have advised me that if I am considering graduate school (which I am), to just go straight for a PhD instead of stopping at a MA. Unfortunately, my family is currently in a terrible place...
  11. M

    Stargazing Telescope Design: Calculating Total Distance from Primary Mirror to Eyepiece

    I am currently in the middle of constructing a Newtonian reflecting telescope and I had a question. The focal length for my primary mirror is 1500mm and 3mm for my eyepiece. My question relates to the path of the light inside the tube of a telescope. I understand that in a Newtonian reflector...
  12. Gravitational Waves: A New Era of Astronomy Begins

    Gravitational Waves: A New Era of Astronomy Begins

    Join some of the very scientists responsible for this most anticipated discovery of our age and see how gravitational waves will be used to explore the universe like never before.
  13. Oganesson

    I Is Jupiter too big to orbit the Sun?

    I read the Jupiter is so big that it doesn't really orbit the sun. Is that true?
  14. SpaceEagle

    Studying How can I combine Astronomy and Technology?

    Hallo, First of all I want to say that I still don't have to choose what I want to do for a couple of years, but I like to think ahead, Im asking my self if there is a way to combine my love of astronomy and technology\engineering for what I want to study and do as a job.as I am very...
  15. lucivaldo

    B Why Were Planets Visible to Ancient People but Not Us?

    Let's be honest...Why were planets visible to the ancient people and not to us humans any longer? Is it because the planets distanced? How can some planets distance themselves while others don't? It's said that light pollution has affected the visibility of planets in the sky, whereas there...
  16. russ_watters

    Stargazing Telescope or Binoculars for First Astronomy Device?

    A recent short-lived member got me thinking about the issue of telescope vs binoculars for a first stargazing device again after a few years of the issue sitting dormant. I hadn't participated in the particular necroresurrected thread, so it didn't have my take on the issue. Here it is: It...
  17. V

    Relativity of motion and astronomy

    Greetings, One of the basic postulates of relativity is that the laws of physics hold equally well in all frames of references. This got me wondering about the geocentric model of solar system which necessarily gives rise to motions of peculiar kinds. For example, the epicycles, which are...
  18. C

    Programs What Should I Major In: Passion or Job Security?

    Hey guys. I am in my last year of high school and I need to figure out what my major is going to be, since I will be applying to universities next summer. I am really interested in astronomy but I know I would not be able to get a job in my country with a degree in either astronomy or...
  19. P

    B How can I do Astronomy from home?

    I just graduated high school and have quite a bit of free time. Since a lot of Astronomy today is done via computers, I was wondering if I can analyze data and contribute to the field of Astronomy by sitting at home, somehow, if possible. I've searched around and gotten sites like this...
  20. O

    Best domains of astronomy to contact super-advanced E.T.?

    Hello.If one’s goal was to contact a technologically superior extraterrestrial being (or a group of beings, or a civilization), which domain(s) of astronomy should one specialize in precisely?1) Which type of astronomy should one specialize in? Computational astronomy Experimental astronomy...
  21. Oganesson

    I Can someone please explain to me Leavitt's law?

    And how we use it to calculate distances from stars to the earth.Thank you
  22. A

    Schools Anybody graduate from Yale's astronomy program?

    How hard was it to get in? How was your experience? I currently study finance(1 year done) and I got accepted to the University of New Haven on scholarship. I plan on taking extra classes in math and physics, so if I decide to pursue a degree in astronomy I will have the pre reqs done...
  23. M

    Other Preparing for Physics and Astronomy Studies

    I'm just started my summer before my four years of undergraduate studies. I plan on majoring in Physics and minoring in Astronomy. I hope to eventually go to grad school to get a PhD in Astrophysics. I was wondering if there are any resources you guys could recommend I use to help prepare me for...
  24. James Webb Space Telescope Instrument Installation

    James Webb Space Telescope Instrument Installation

    Time-lapse video of two dozen engineers and technicians successfully installing the package of science instruments of the James Webb Space Telescope into the telescope structure.
  25. Physics-UG

    Programs Physics and mathematics or physics and astronomy?

    I was hoping someone could shed some light on a current predicament I'm having. Although I don't have the knowledge to make a real decision yet (only first year), I enjoy string theory, quantum mechanics (and quantum gravity), as well as cosmology. Based on these areas of interest, I'm unsure of...
  26. G

    Stargazing Why Can't I See Anything Through My Newtonian Reflector Telescope?

    I bough a Newtonian reflector a while back, after it was assembled I couldn't see anything through the eyepiece. The viewfinder works perfectly fine, but when I look through the eyepiece it is just pitch black. Any suggestions?
  27. Zachary Eckert

    Physics Assessing the risk of pursuing physics

    Hello, I've done pretty thorough research and realize that this topic of "Is physics hard, can I handle it, how risky is it, etc" has been beaten to death. But I'm going to ask for advice anyway haha. So the situation is, I have always had a love for astronomy since I was a child, and nature...
  28. Bumpeh

    Courses Good Math Electives for Astronomy

    Hello everyone! So, I'm currently double majoring in Math and Physics at my University. My end goal is to hopefully go onto graduate school to earn a PhD in Astronomy, the specific areas of Astronomy I'm interested in are Observational Astronomy, Instrumentation and Planetary Science. Here are...
  29. F

    Calculating focal length from a number of focal ratios

    Homework Statement A telescope has a focal ratio of f/7.5. You wish to use it with a spectrometer that requires a f/10 beam as its input. Compute the focal length of a 50mm diameter lens that, when inserted into the beam 150mm in front of the unmodified focal plane, produces the required beam...
  30. V

    Studying How much time it takes to know all physics concepts?

    I have completed my engineering by now. I have decided to continue my further studies in Mathematics and to be aware of all physics concepts required for research. How can I study all physics concepts from home and what time would it take for me ?
  31. P

    Programs How do I decide which sub-field of Physics I want to pursue?

    I'm a freshman at UT Arlington and I will get my undergraduate degree in Physics from that university. Now, I am sure that I want to pursue Physics, but not quite sure of the sub-field. I lean towards Astronomy a lot, and I will probably end up doing that. The problem is that my university...
  32. SOUKRAT

    What is the first step to pursue astronomy?

    Hi everyone I am mechanical engineering student ,after my degree I am planning to have a degree in astronomy so I need advises to help me study astronomy as a self-study in summer ! what is the first textbook should I buy ?? what is the curriculum in this field for campus ( name...
  33. jedishrfu

    Kid Didn't Discover Lost Mayan City via Astronomy After All

    IMPORTANT EDIT: Mayan researchers declare story to be untrue. The Maya didn't follow astronomy to layout their cities and the 15 yr old actually discovered an old corn field. http://news.discovery.com/earth/15-year-old-didnt-discover-mayan-city-after-all-160511.htm and here's some backstory to...
  34. A

    A How do we say that the universe we live is 3 dimensional?

    i opine that the universe is not 3 dimensional at all. its not build up of 3 coordinates at all. it is because, we humans could see 3 dimensions it doesn't mean the space metric is of 3 dimensions. suppose there's a super being living on an Earth like planet of some other galaxy whose viewing...
  35. A

    Research Project Ideas for First Year Astronomy Student?

    Hi, I am wondering what are some good ideas for a first year undergraduate science research project? I am majoring in Astronomy so am after some ideas. My special interests are Pluto, Black Holes and of course Planet X.
  36. H

    Schools Undergraduate in university with no astronomy

    Hi everyone, I'm matriculating at a local university in Physics in a few months and my ultimate goal is to do a PhD in astronomy/astrophysics at a reputable US university after I graduate. I am aware research experience as an undergraduate is paramount in securing a good PhD spot and I have...
  37. GiantSheeps

    B What would happen if the Sun collided with a similar star?

    What would happen if the Sun collided with an exact copy of itself? I can't find any information online about this exact scenario. So what would happen to the Sun? What would happen to the Earth and the rest of the planets? Any information or help would be greatly appreciated. Thanks so much!
  38. W

    Studying Maths, Physics, Astrophysics, Astronomy or Cosmology?

    Hi, I don't know where to begin, please forgive me for asking this if it's been answered before. I'm confused, I don't know what to study, can you help me out? I'm fascinated by the Universe, my only regret in life is that I don't live in space far away from humans. I've always liked...
  39. Barely_Conscious

    I How would one know whether a star would be observable?

    I'd like to answer this yes or no question for a number of objects: "Is this star, at any point between these two times, going to be above the local horizon?". Say, I'm at the prime meridian at a latitude of 50 degrees, and I want to know whether, between the sidereal times of 11:00:00 and...
  40. kcookson251

    B Unraveling the Mystery of Dark Matter: Is it a Different Type of Gravity?

    Dark Matter is every where and always passing threw us right? It apparently hold everything in place in our universe. We know it there but can't detect it. We see the results, but we don't really see who's responsible. What If dark matter was basically a different type of gravity? And the...
  41. J

    Teach Astronomy in First semester or Second?

    OKay, so this may be a weird place to post this question, but I value the opinion of the members here whether they are current or former students or current or former teachers. I'm setting up an astronomy class for the high school I work at, but unfortunately the way the schedule works is that...
  42. Janus

    Insights How Representative is the Night Sky? - Comments

    Janus submitted a new PF Insights post How Representative is the Night Sky? Continue reading the Original PF Insights Post.
  43. NatFex

    B How Does Stellar Parallax Measure Distance?

    This isn't a very technical series of questions, just some passing thoughts I had whilst looking over some notes I had on stellar parallax distancing. Stellar parallax is always described as a means of "measuring the distance to stars." But from where? What I mean is, the distance, or the side...
  44. Mike Schmaltz

    What ignited Mike's scientific curiosity at age 62?

    I'm 62, interested in science, especially astronomy, and retired from the phone company.
  45. Prez Cannady

    I Detecting organic compounds in interstellar dust

    Two questions: 1. What tools and techniques are typically used to determine and plot spatial distributions of compounds--particularly organic ones--in interstellar dust? 2. Is it presently possible to determine distributions of compounds along arcs distant from the galactic center? If so, can...
  46. D

    Schools Which PhD Program Should I Choose: UMass Physics or CWRU Astronomy?

    I have offers from UMass Amherst Physics and Case Western Astronomy for their respective Phd programs. I'm having a tough time deciding between the two. Leaving aside the differences due to astronomy vs physics, what other factors are important to consider while making a decision? UMass Physics...
  47. Shailesh Pincha

    I Rotation curve of galaxy Keplerian method

    There are 2 unknowns in the formula. The time period of rotation and the mass enclosed by orbit is Star. So how could we calculate the expected time period of rotation of stars in a galaxy and thus velocity of stars.
  48. astro_chara

    Programs Start a Physics & Astronomy Club: Ideas & Advice

    I'm planning to start a physics and astronomy club at my high school my junior year (next year). I have an idea of who I can collect to the club, but before I bring it up to the school, I need some ideas for the club. Should there be activities, like building a mini particle accelerator, or a...
  49. A

    How to find universitites giving Astronomy and Astrophysics

    Hi I am interested in having more information for undergraduate courses in Astrophysics. I am looking for univs in Western Europe predominantly, but information on univs in other countries can help too. I wanted to know as to how to find universities that allows one to graduate in the fields...
  50. Alltimegreat1

    Is Fluency in Russian Beneficial for Astronomers in the US?

    Assuming a candidate for an astronomer position in the US fulfills the standard skills and requirements, would it be seen as an added plus to speak, write, and understand Russian fluently?
Back
Top