The sun Definition and 634 Threads

  1. W

    Estimate Sun's Rotation Period as a Neutron Star

    Could someone help me start this problem. My mind it in the angular momentum mode and I am having trouble seeing where to start on this one. :confused: The sun's radius is 6.96E8m and it rotates with a period of 25.3d. Estimate the new period of rotation of the sun if it collapses with no...
  2. D

    Earth's Orbital Speed Around the Sun

    The Earth has an orbit of radius 148 million km around the sun. What is the speed of the Earth on this orbit? dont know how to do it i have used a couple of different formulas and haven't gotten it right can anyone help?
  3. S

    What Is the Correct Calculation for the Mass of the Sun?

    hey there, i am having trouble with what should be a really easy question! ********* calculate the mass of the sun assuming that the Earth's orbit is circular and with a radius of 1.5 * 10^8 km i got the period of the Earth's orbit around the sun in seconds: 60*60*24*365.25 then used...
  4. G

    How Strong Is the Sun's Gravity at Earth's Orbit Distance?

    What is the acceleration due to gravity of the sun at the distance of the Earth's orbit? i have no idea where to begin. Help
  5. S

    Find mean distance from asteroid Icarus to the sun

    Ok, I keep trying to do the following problem: ----The asteroid Icarus orbits the Sun like the other planets. Its period is about 410 days. What is its mean distance from the Sun? (Hint: You can derive the mean distance with the paramters known for the Earth: Period of the Earth = 365 days...
  6. I

    Why doesn't the orbit increase in radius?

    The following site shows that when a sail is orientated so that it faces away from the sun, the net force is pushing outwards from the sun and is also opposing the orbit. http://solarsail.jpl.nasa.gov/introduction/how-sails-work.html It makes sense that the craft should slow down, but why...
  7. M

    Theoretical Extinguishing of the Sun with water

    I fear that I am way out of my depth here, being a mere mathematics student but anyway... We have been asked by our mathematical modelling lecturer to calculate the quantity of water required to extinguish the sun. I'm pretty sure that the exact physics and processes of the sun are not...
  8. B

    How to calculate the time taken for the sun to cool down?

    We're asked how long would it take for the sun to cool down if nuclear energy production suddenly came to a hault This is the question asked in one of my lecture courses given that the radius of the sun is ~ 10^9m, mass ~ 10^30 kg, luminosity ~ 10^26, and G = 6.7x10^-11 Am i correct in...
  9. Q

    GRE Problem #66: orbit of the spacecraft about the Sun?

    Dear reader, here is a neat problem, but kindof over the edge. when it is about the same distance from the Sun as is Jupiter, a spacecraft on a mission to the outer planets has a speed that is 1.5 times the speed of Jupiter in its orbit. Which of the following describes the orbit of the...
  10. wasteofo2

    When exposed to the sun, why does your skin darken but your hair lighten?

    I know that when your skin is exposed to a lot of sunlight it turns darker in order to try to absorb some of the light's energy, which can help avoid burns, but why does your hair become blonde?
  11. B

    Does the Sun's Changing Mass Affect Its Gravitational Pull on the Solar System?

    Through nuclear fusion the Sun slowly losses mass as it is converted to energy. The Sun also losses mass through coronal mass ejections. So after a large amount of time would this change in mass of the sun create a measurable change in the gravitational influence the Sun has on bodies in the...
  12. W

    A question about the sun and blackbody

    Why is the spectrum of sunligt similar to that of a blackbody?
  13. D

    Calculating Solar Sail Size for Propulsion Against Sun's Gravitational Force

    whats up guys. help me out NASA is giving serious consideration to the concept of solar sailing. A solar sailcraft uses a large, low-mass sail and the energy and momentum of sunlight for propulsion. The total power output of the sun is . How large a sail necessary to propel a 10,000-kg...
  14. D

    Why Does Earth Experience Only Two Extreme Distances from the Sun in Its Orbit?

    Currently the Earth has two extreme distances from the sun: Apogee and Perigee (one minimal, one maximal). Shouldn’t there be four extreme distances between the sun and the earth: pair of opposite minimums and pair of opposite maximums? Both the sun and the Earth have mass. So, there must be...
  15. C

    Earth transits the Sun as viewed from Mars in 2005?

    So I was playing around with Celestia and watching last year's transit of Mercury and this year's transit of Venus. They seemed pretty accurate to diagrams I've seen for ingress/egress locations. Then I got an idea. I flew to Mars and went looking for a transit of Earth, and to my surprise I...
  16. S

    Is it possible to change the helium of the sun to hydrogen

    sir, I have to questions, 1. is it possible to change the helium of the sun to hydrogen. 2. can laser stop the electromagnetic wave if laser is charged to the electromagnetic wave face to face. soumya
  17. R

    Prove that the earth goes around the sun

    I find it obvious, as did many previous people, that the sun goes aroudn the earth. I of course know htis to be untrue as it has been drummed into me again and again for the past 16 years. Can someone please prove to me (so that i can prove to others as well) that the Earth goes around the...
  18. G

    Exploring the Mass & Shape of the Sun

    How can the sun have much mass if it's just a bunch of gasses? And also what keeps the sun in a circlular shape? I've always wondered.
  19. R

    Why do all the planets orbit the sun?

    This might seem like a silly question to most of you but I’m going to ask it anyway. Why do all the planets orbit the sun?
  20. L

    Stars closer than thought. How the sun affects the light path

    Distance to star, much little Considering the effects of the relativity theory in terms of the curvation of space, I am wondering if for the calculation of the distance to the stars using the parallax method (below 100ly), the effect that the sun is creating a deformation in the solar system...
  21. G

    What does the sun look like from Mars?

    I have a few questions about Mars I hope you can enlighten me about. Firstly,what does the sun look like from Mars,that is the comparative size of the disk with that on Earth? I saw a very poor picture somewhere on the web but couldn't really get a handle on it,perspective/lack of points of...
  22. Nibles

    What Would Happen if the Sun Was Blue?

    What if our Sun was a blue giant or was some other color? Would the planet be lit with that color? What would it be like? Our Sun is yellow/orange, but we don't live under that kind of light, our light is more just white, but I don't know why. How would the color of a star be apparent on its...
  23. M

    How many earth years is Jupiter's orbit around the sun?

    How many Earth years is Jupiter's orbit around the sun? is it 162 years?
  24. S

    How much mass does the sun add to the earth each day?

    How much mass does the sun add to the Earth each day?
  25. N

    Tides due to the moon vs. the sun?

    Tides due to the moon vs. the sun? The acceleration of gravity on the Earth due to the sun is 177 greater than gravity on Earth due to the moon. Why are the tides predominantly due to the moon and not the sun, in spite of this number? Nautica
  26. wolram

    The sun attractive to the earth and holds us in orbit.

    posted by MARCUS. if it was only energy density that would be mysterious enough but have you registered that it is, to a small extent, the pressure inside the core of the sun that makes the sun attractive to the Earth and holds us in orbit...
  27. G

    Centre of the earth is hotter than the sun

    I have heard that the centre of the Earth is hotter than the sun, and it is the place where hell is. What are your opinions on this?
  28. brum

    Is the Sun More Spherical or Oval? Investigating the Shape of Our Closest Star

    is the Sun a sphere (like the Earth) or is it more oval-shaped and elliptical? because, since the Earth is (nearly) spherical, the moon has a (nearly) circular motion. BUT, many (if not all) of the planets in the solar system have ELLIPTICAL orbits. This leads me to believe that the Sun...
  29. Tyger

    Why Does the Sun Look Yellow When Paper Looks White?

    When you hold a piece of paper up to sunlight it looks white. But when we look at the Sun it looks yellow. Who's first with the answer?
  30. marcus

    How long before the sun goes red giant?

    A french poster (ant284) just came to HomeworkHelp with a question about the lifetime of the sun. Some say the sun will go red giant when it has consumed 12 percent of its hydrogen. The sun is now 75 percent hydrogen. We know its mass so we can tell how much hydrogen is supposed to be...
  31. marcus

    Calculating the Sun's Bending Angle on a Ray of Light

    By how much, if at all, is a ray of light bent when it passes by the sun a million miles from center? The bottom line is, do you have an order-of-magnitude feel for the sun's gravity? Can you judge the rough size of the bending angle well enough to spot it in the line-up? In natural units...
  32. H

    Exploring the Relationship Between Electrons and Nuclei: A Scientific Inquiry

    i want reply to "Why Do Electrons Move?" (sorry, but the thread is closed..) i think the sun is the white hole. i think all electron comes from the sun. and electron goes into the sub-nucleus. i think sun is not burn out. it will be permanently. from this point of view, i want ask...
  33. marcus

    What is the weight of a copy at Earth's average distance from the sun?

    At this distance from the sun, how much would a copy weigh? In other words, with what force (in Newtons, or Planck units, or dynes, or tons---your choice) would a copy be attracted if it were at Earth's average distance? How about this? The Earth's speed, in its roughly circular orbit...
  34. B

    Understanding the Sun's Gravity and Its Impact on Planetary Orbits

    I am missing something here. In old Star Trek episodes, Captain Kirk and Captain Picard were often caught in the gravitational pull of a nearby sun and had to really turn on the engines to escape this terrible force. Where on Earth did this concept of the sun’s gravity come from? In case...
Back
Top