What is the temperature of a Nebula?
152097
Different nebula can have different temperatures.  Nebula like the Orion Nebula are really hot because the stars in the center part of the nebula are heating them up to around 10,000 Kelvin.  However, when stars aren't around, nebula can get extremely cold, just a few degrees above absolute zero.\n\nNebula that were formed by exploding stars, such as supernova remnants or planetary nebula, can be even hotter, into the millions of Kelvin.  This is because of the massive amounts of energy that were released in the star's death.
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.
1002235
The planet's temp. depends on their distance frm the sun. Otherwise it's all vaccum and thus can't have temp.
23967
Stars are massive, glowing balls of hot gases, mostly hydrogen and helium. Some stars are extremely hot, while others are cooler. You can tell by the color of light that the stars give off. If you look at the coals in a charcoal grill, you know that the red glowing coals are cooler than the white hot ones. The same is true for stars. A blue or white star is hotter than a yellow star, which is hotter than a red star. Temperature of stars range in the high hundreds to thousands degrees F. So to touch the stars that are in the sky is almost impossible, as your body would burn due to high temperatures surrounding them.
407489
There's no single diameter for all nebula (plural is 'nebulae'). Some are up to 100-light years across, while others might be as small as .5 light years.\n\nhttp://reference.allrefer.com/encyclopedia/N/nebula.html
597656
Tarantula Nebula (NGC 2070)
532257
A good approximation to the distribution of electromagnetic radiation emitted by the sun is given by the equation for a blackbody with a temperature of 5780 Kelvin:\n\nPower (Watts/meter^2 surface are/meter wavelength) = \n  2*pi*h*c^2/L^5*(exp(h*c/L*k*T)-1)\n\nwhere\n\nh = Planck's constant (6.626 x 10^-34 Joule*sec)\nc = speed of light (2.998 x 10^8 meters/sec)\nL = wavelength (meters)\nk = Boltzmann's constant (1.38 x 10^-23 Joule/Kelvin)\nT = temperature (Kelvin)\n\nThe sun's power output peaks in the visible portion (around a wavelength of 500nm) of the electromagnetic spectrum, but it emits over the entire range of possible wavelengths.\n\nIn reality, the solar spectrum is much more complicated than a simple blackbody curve because of the absorption of specific frequencies by the atoms making up the sun, as well as temperature inhomogeneities and effects due to the sun's magnetic field.
225153
That's an interesting question, with a somewhat complex answer.  There are several factors involved:\n\n1.)  If the black hole is actively accreting gas--especially if it has a disk of hot gas (an accretion disk) around it--the temperature at the event horizon will be very hot.  Almost every black hole we know about is like this.\n\n2.)  If the black hole is just floating through space, the temperature at the event horizon will still be hot, because the few gas particles it encounters will be accelerated tremendously until they are drawn into the event horizon.  The gas would be very thin though, and the black hole itself would probably be undetectable.\n\n3.)  Black holes *do* in fact have an intrinsic temperature, as theorized by Stephen Hawking; Hawking radiation is believed to carry away mass from every black hole at a very slow rate.  This means that black holes radiate energy, albeit at a very, very slow rate.  In fact, the temperature of a black hole at its event horizon as calculated by Hawking radiation is far colder than the cosmic background radiation (that is, the general temperature of space at the present era).  Many eons hence, however, once the universe becomes much colder due to expansion, Hawking radiation will be important in controlling the future evolution of black holes.
909214
The average temperature of the universe is less than 3 degrees above absolute zero.  So starlight (sunlight) already travels in the temperatures about which you ask at a constant speed.\n\nOf course temperature is a measure of the average kinetic energy of a volume...  and is there is little mass inside a volume, there is little KE, so vacuum must be very close to zero.
255712
The temperature at the centre of the sun is 15 million degrees Celsius, whilst temperatures on the edge of the sun can be as low as 4,000 degrees Celsius. \n\nIt may also interest you to know that a laboratory here on Earth has created a temperature of 510 million degrees Celsius, many times hotter than the hottest part of the sun.
228115
A Planetary Nebula is a misleading name.  At the end of a lower mass star's life (for stars up to about 8 times the mass of the sun), the star puffs up, and loses the outer layers of gas surrounding it.  All this gas goes out into space where it can be seen as what we call a planetary nebula.\n\nOriginally the word "nebula" was applied to any astronomical object that was not a star or a memeber of our solar system (planets, asteroids etc), the word essentially means "cloud."\n\nAs telescopes got better people started to find many different types of nebulae. A Spiral Nebula looks like, well a spiral, today we know that these are spiral galaxies.  Planetary Nebula were named because the looked round, and a number of them had the same greenish color that Uranus had been seen to have by Hershel.
628638
Depends on who you read.  Ranges are from 700-1300C or 820-1020C.\n\nOne site says, \n"temperature between 1300 and 700 degrees C"\nhttp://www.cobweb.net/~bug2/rock7.htm\n\nWhile another says,\n"We show that the mantle in this region is at a minimum temperature of 820 C and a maximum temperature of 1020 C; the latter is some 200 C colder than that suggested in a recent interpretation of an observed collocated low velocity zone from a teleseismic survey"\nhttp://www.dias.ie/~ajones/papers/100.pdf
492304
Nebulas: One of the most beautiful phenomenon in the universe. They are made up of gas left behind by stars forming or exploding. \n \nTypes/Classes of nebula: planetary, supernova remnants, diffuse nebula\n\nPlanetary nebulas: Resemble planets, and are actually left over shell material from forming stars during their giant Red Stage.  \n\nSupernova: Remnants are exactly what they say: supernova nebulas are remnants of a star that exploded.  Left over remnants become surrounded by gas, causing a nebula.   One of the most famous supernova nebulas is the crab nebula in the star constellation Taurus.\n\nDiffuse nebulas: Extremely large, and can be light years in width.  They have no definite shape, and are either light or dark.
80719
You can however determine the temperature of the body that emits the radiation. The higher the energy of the photon ,gamma rays being the highest, the higher the temperature of the body. This is how we determine the temperature of stars.
726747
Hot gas in the Universe swirls together sometimes and forms a nebula. A nebula is like a VERY big cloud in space that swirls together over millions of years and cools down a little. The gas swirls and cools together tighter and tighter until the gas starts to form lumps . . BIG lumps . . .HOT lumps . . .big hot lumps that swirled and spun around. Our Sun is one of those lumps. Our Sun is a star. When the Sun was still a spinning lump, parts of it splashed off of it as it spun around. Those small lumps of hot gas were flung into cold space and cooled down and became less hot gas and more like lava. The smaller lumps kept spinning and cooling down until they became planets. The planets float around the Sun, captured in her invisible tentacles of gravity. We call a Sun and her family of planets a "solar system". There are millions and millions and millions of solar systems in the Universe. The hot gas that first made the cloud nebulas started out as energy or light. Tiny bundles of that energy formed and we call those bundles, "photons". Photons come together to form matter, like the atoms of gas. Here is a real picture that we have made of the beginning of the Universe when all that energy first appeared:\nhttp://www.princeton.edu/pr/pwb/03/0217/\n\nHere is a picture of a nebula:\nhttp://www.saskschools.ca/~gregory/space/sp/nebula.jpg\n\nStar formation website:\nhttp://sscws1.ipac.caltech.edu/Imagegallery/subcat.php?cat=Astronomical_Images&subcat=Star_Formation
267283
Empty space itself cannot have a temperature.  However, if you put a physical object into space, it will reach a temperature that depends on how efficiently it absorbs and emits radiation and on what heating sources are nearby.  For example, an object that both absorbs and emits perfectly, put at the Earth's distance from the Sun, will reach a temperature of about 280 degrees.  If it is shielded from the Sun but exposed to interplanetary and interstellar radiation, it reaches about 5 degrees.  If it were far from all stars and galaxies, it would come into equilibrium with the microwave background at about 2.7 degrees.\n\nSpacecraft (and spacewalking astronauts) often run a bit hotter than 280 K because they generate internal energy.  Arranging for them to run at the desired temperature is an important aspect of design.
896788
Neutron stars lose heat very quickly after "birth." They start off at approximately 10^12 Kelvin (or Celcius, because at those temperatures it doesn't matter!) and within a few hundred or thousand years can drop full orders of magnitude to 10^11, and even to a core temperature of 10^9 K.