Does the sun have a dark companion star orbiting it?
346131
no theres no such thing as a dark companion star
188133
At night?\n\nSeriously, you might find this page helpful:\nhttp://solarprobe.gsfc.nasa.gov/\n\nAnd for the record SOHO (mentioned in another answer) doesn't go to the sun, it simply has an uninterrupted view of the sun (unlike folks on Earth or conventional satellites which lose sight of the sun... at night).
64343
It varies place to place and even month to month.\n\nWhat one needs to consider are three things: which are the brightest stars in the sky (as these are going to be the first to be seen as the sky darkens), what times of year are these stars visible RIGHT AT DUSK, and from which parts of the globe are they visible?\n\nThe brightest star in the night sky is Sirius.  Siruis is located in the southern sky, but is visible from the vast majority of the Northern hemisphere because it isn't too far south.  If you're in a part of the world where Sirius can be seen (all but Canada, Alaska, Russia, Scandanavia, etc), and at a time of year when it is in the sky right at dusk (mid winter to early spring), then Sirius (also called the Dog Star) will be the first to be visible.\n\nOther bright stars:\n\nCanopus (visible primarily from the southern hemisphere and the tropics or subtropics)\n\nArcturus (visible throughout the Northern hemisphere, would be in evening sky probably from spring to mid summer)\n\nAlpha Centauri (the closest of all stars, visible primarily from the southern hemisphere and the tropics or subtropics)\n\nVega (the one in the movie Contact, visible throughout the northern hemisphere, in evening sky around late summer through autumn)\n\nCapella (visible throughout the Northern hemisphere, probably in evening sky around winter into early spring)
579859
I assume you mean "star" and not "sun", as in OUR sun, in the first question.  In that case, a supernova is essentially the spectacular explosion that occurs when a star of a significant sized mass ends its life.  IN that case, all the elements with a periodic table number higher than oxygen are created.  In addition, the remaining core of the dead star becomes so dense, that it creates an object that even light can't escape.  This object is now a black hole.\n\nOur sun is not big enough to supernova, therefore it will just die out and become a black dwarf when it is dead.\n\nDefinition from the Big Wiki...\n\nhttp://en.wikipedia.org/wiki/Supernova
592819
When the Sun has Sunspots you can see that they revolve around the Sun.\n\nIt basically rotates similar to how the planets rotate.\n\nRotate not orbit.
334251
The sun is not a planet.
300780
there are several (you did not provide enough details)...could be a sun, galaxy, nebula, etc.
39095
No. \n\nStar:\nA self-luminous celestial body consisting of a mass of gas held together by its own gravity in which the energy generated by nuclear reactions in the interior is balanced by the outflow of energy to the surface, and the inward-directed gravitational forces are balanced by the outward-directed gas and radiation pressures\n\nPlanet:\nA nonluminous celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves.\n\nSo, stars are self-luminous (have their own light) and are stationary. Planets don't produce their own light and revolve around a star.
651836
It is definitely the sun. Alpha Centauri is nearly 4 light years distant. The sun is nearly 8 light minutes distant.
1107060
You can tell whether a point of light in the dark sky is a satellite or star usually by whether it moves or not. Stars are very far away so they look stationary. Satellites usually moves across the sky. Whether or not the the satellites are Japanese, American, or Russian, you have to look up the satellite in astronomy programs that plot satellite trajectories. You can't tell just by looking.\n\nAlso, some bright lights can be just airplanes flying at high altitude.
752275
I would say that it is made up of hot low-density gas.  The assumption in the question is that there are no dark spectral lines.  That means that there is no "black body" radiation being transmitted through a cooler gas.  A hot, dense gas with strong molecular interaction would tend toward a more continuous spectrum; without dark lines there isn't a cooler gas surrounding it.
373960
This has been pretty well answered but I thought I'd clarify.\n\nThe Sun is the name of our solar system's star, the star we call home.  (Similarly the Moon is technically the name of Earth's only natural satellite, other planets have natural satellites which we commonly call "moons").  Other stars have different names (like Vega).\n\nWe are just finding extrasolar planets (planets that orbit other stars) and it is likely that there are many stars out there with planets and even solar systems (more than one planet orbiting them).  However it is also very likely that many stars will not have any planets at all.\n\nIf you are interested in this, here is a fun website about extrasolar planets: http://planetquest.jpl.nasa.gov/index.cfm
1116091
Right now, Farlack of the Geltrans on Planet Flibbering, orbiting the Dog star of Mecaea is asking the same thing of his peers on their version of the internet.\n\nBut seriously... all those stars... billions of them are all suns.  If only half of them have a few planets revolving around them, one of them has to have life on it.
216942
Our sun is indeed a star. As a star,it will go through all the phases that other stars go through like BIG BANG and etc. Yes,our sun will explode one day and that day will be in another million or billion years of time. So,don't worry about it now. Worry about your great grandchildren. Anyway i hope that i had answered your question. Take care.
236374
A very bright "star" that's usually reported is the planet Venus. It rises and sets close to the sun and has therefore in ancient times been given the names Eveningstar and Morningstar. \n\nIf you see a star that sets or rises just hours before or after the sun and is exceptionally bright, you're with highest probability looking at our neighbour planet Venus.
933495
Binary systems can and do have planets orbiting (25% of all known extra solar planetary systems are around binary or multiple star systems). Some systems in which the stars are close to eachither have the planets orbiting both stars, some systems have planets orbiting only one star in the system. Many planets in binary systems have highly eccentric orbits (like comets), are widley seperated from the star (600-2500 AU, the habitable zone around solar type stars is 3 AU). \nHabitability depends on so many things that it's really hard to say for sure if any exist but it is certainly possible.
905459
Yes, it is. It is the third closest star to The Sun (Sol) after Proxima Cenaturi and Barnard's Star. "A very cool, main sequence red dwarf (M5.8Ve), Wolf 359 is our Sun's dimmest stellar neighbor within 10 ly, with less than 2/100,000th of Sol's luminosity." It is 7.8 light years aways and is in the constellation Leo.