Regarding shape, stars appear as a dot while planets appear spherical. Short answer is NO. A moon orbits a planet. So far, they are just theoretical objects. You might be able to with a red dwarf but it would be a very low mass one with a planet the size of Jupiter or larger. Of course, as a main sequence star (not a brown dwarf), it has to be a lot more massive than Jupiter. If the planet is made of metal (a technical term among astronomers that means anything by hydrogen or helium), it will be harder to fuse, so it can be bigger without being a star. This main sequence star is the size of Saturn. The mass and radius above come from Wikipedia article. If we consider neturon stars as stars then yes, a planet can be larger, but the star will remain the most massive. It is about 1,200 light-years from Earth in the constellation Lyra. And that is why stars are bigger than the planets. Anonymous. A gas giant with at least twice Jupiter’s mass, it orbits Pollux at a distance of 1.65 astronomical units — a little farther from its star than Mars is from the Sun. The smallest red dwarf stars are smaller than Jupiter. The Sun has about 1000 times the mass of Jupiter. Planets are typically brighter than stars. Planets are typically brighter than stars. Unless we don't consider a pulsar as a star of course. This star is probably an ultracool M-dwarf. It will be quite some time before we can resolve a first generation star. It is a Jupiter sized planet orbiting a roughly Earth-sized white dwarf! Astronomers have found the tiniest full-fledged star known, an object just 16 percent bigger than Jupiter. Favourite answer. Relevance. As I recall, above a certain size, planets get smaller with increasing mass because the pressure at their core gets great enough to compress the hydrogen enough to make that possible. Lv 7. Researchers say that a space rock that landed in Costa Rica on April 23rd, 2019, came from an asteroid that exists as a We know that these kinds of circumstances exist, but we have yet to observe such an instance where the two reside in the same system together in nature, and that’s one of the biggest challenges behind answering this age-long question. With the recent explosion of extrasolar planet discoveries, some relatively nearby, astronomers and space enthusiasts wonder how habitable some of these planets would be for humans. yet, both stars and planets have different sizes, such as a white dwarf star is smaller than Jupiter. Have a hobby-level telescope question? If a star had a planet larger than it and if that planet happened to transit its sun as seen from Earth, then yes that "transit" would actually be an eclipse and the star would completely disappear for a short time. It might seem to disappear, but some light in a corona shape, would still be technically heading towards us. The sun is what we call a yellow dwarf star. That planet, of course, is Earth. Show me what you got... 3 comments. ... Nebulas are vast clouds of dust and gas that are remnants of exploded stars or in other cases, nurseries for where stars A planet found in December 2009, GJ 1214 b, is 2.7 times as large as Earth and orbits a star much smaller and less luminous than our Sun. Just one handy quote: The Sun weighs about 333,000 times as much as Earth. ... Navigating beyond Earth's orbit is tricky. So I'm just wanting to know, is it theoretically possible for an extremely huge exoplanet to be larger than its extremely small host star? UY Scuti (BD-12°5055) is a red supergiant star in the constellation Scutum.It is considered one of the largest known stars by radius and is also a pulsating variable star, with a maximum brightness of magnitude 8.29 and a minimum of magnitude 10.56. Edit: I forgot to say that the white dwarf remains much more massive than the planet. (Please read our subreddit rules first!) In terms of mass, neutron or white dwarf stars could be packing ten solar masses’ worth of matter into a blob about the size of a metropolitan city. Others have answered, and I agree that it is theoretically possible for a red dwarf system. 0 3. Exoplanet Habitable Zone Around Sunlike Stars Bigger Than Thought. Well before that, though, cold giant planets reach their maximum radius around 3 Jupiter-masses, and start shrinking in radius as mass increases from there. (White dwarfs also shrink as they get more massive for the same reason.). but if it is stellar remnant, then you got it. 75% Upvoted. That's fundamentally caused by an increased fraction of interior degenerate matter in the form of liquid metallic hydrogen, which has the wacky property that the more of it you add, the smaller it gets. Planets Jupiter-mass planets are about as large as a planet can get. Anthony is a technology junkie that has vast experience in computer systems and automobile mechanics, as opposite as those sound. On the other hand, because KELT-9b's host star is bigger and hotter than the sun, it complements those efforts and provides a kind of touchstone for understanding how planetary systems form around hot, massive stars," Gaudi said. So they can. Make this planet too big and you risk losing ozone. To date, astronomers have catalogued over 1,000 exoplanets — some of them rocky and parked within their host star's habitable zone. No, it is impossible for a planet to be bigger than a star, it it were, it would have became a star itself. He asked if an "extremely huge" planet can be large enough to be bigger than its star, which can't happen. Even though it is considered a "dwarf" it is bigger than 90% of the stars in the Milky Way. Direct your astronomy related questions here! Therefore no planet could ever be remotely close to the same mass as the sun. Yes, in fact the first confirmed extrasolar planet is bigger than its star: The planet PSR B1257+12b has a radius of at least 7500km, and its star PSR B1257+12 (which … Hypergiant stars are the largest stars in the Universe. That extra energy source tends to increase the radius, at least for a little while. A star of the aforementioned variety would theoretically be suitable enough to support a solar system as large or even larger than one like our own, but due to the circumstances surrounding its size, it would visually appear smaller than a planet like Jupiter despite being more massive. Can a planet be bigger than it's parent star? Relevance. They are no bigger than a city. The KELT-9b planet was found using one of the two telescopes called KELT, or Kilodegree Extremely Little Telescope. A Jupiter mass planet could easily orbit a star of that size, in the sense that Jupiter orbits our sun. It is a dense object with a high surface gravity (300 gs according to the article at the end of the first link). So, with this in mind, is it even possible for a planet to be larger than its host star? Hide Caption If the Sun was a hypergiant star, it would reach out to as far as Jupiter. This thread is archived. The planet is ten times larger. what about planets arround a pulsar? Our solar system has but one planet orbiting in what is commonly known as the habitable zone — at a distance from the host star where water could be liquid at times rather than always ice or gas. ... For the first time, scientists have found water on the moon's sunlit surface. Cookies help us deliver our Services. John. While the star is currently twice the Sun’s mass, it’s expected to puff off enough of its outer layers to enable its core to collapse into a … At 13 Jupiter-masses, a gas giant becomes a brown dwarf and starts up fusion of deuterium. Edit: y'all downvoting this are missing the point of OP's question. The night sky is full of light, most of which is generated by celestial bodies like stars and planets. One of the smallest known red dwarfs is EBLM J0555-57Ab, which is smaller than Jupiter. 6 Answers. The planet GU Psc b, seen in an artist's conception, is about 10 times bigger than Jupiter, and is located about 50 times farther away from its star than the dwarf planet Pluto is from the sun. https://en.wikipedia.org/wiki/EBLM_J0555-57#EBLM_J0555-57Ab. A moon is always smaller than the planet it belongs to, but some large moons are bigger than small planets. But, being denser, the planet could survive inside the giant star, and once the giant star became a planetary nebula + white dwarf core, the planet remained orbiting it every 1.4 days. Related: Everything you need to know about exoplanets. It is the source of light and heat. This suggests main sequence stars may be smaller in radius than gas giants, but this doesn't mean tiny stars will have gas giants orbiting them. ... Scientists hope to use 3D modeling in the future to understand how a rocky planet around a dim star could fare as well. 6 Answers. This bending causes the star to appear to twinkle. Note: The host star is a main sequence star, and not a stellar remnant. Sure, the planet would have to be pretty big (while staying at the same mass), but it could happen. 1 decade ago. *(A detail that I have written up here is quite miss out from the point a lot -.- ) And the reason when you see a stars in night time and it look quite small that is because that the distance between our planet and that star is quite far away. a star is way bigger than a planet. By using our Services or clicking I agree, you agree to our use of cookies. The new measurement of HR 5171 A shows they can be much bigger. They have a diameter over 1,500 times bigger than the Sun. Another tricky candidate for making this statement true are red or brown dwarf stars. The Sciences This Giant Planet is 4 Times Bigger Than its Dead Star Astronomers discovered a Neptune-sized planet orbiting an Earth-sized star. The white dwarf star is making the planet lose some 260 million tons of material every day. So can an asteroid be bigger than a planet? (23 January 2018 - Johns Hopkins University) A planet can be no bigger than about 10 times the mass of Jupiter, an astrophysicist has concluded. It is so large that about 1,300,000 planet Earths can fit inside of it. WD 1856 b was discovered last year. Lv 7. I think OP was asking if a planet can possibly be large enough to be larger than its main sequence star as a matter of happenstance, rather than if its possible for stellar remnants to be smaller than the orbiting planets. The planets in our solar system are much closer to the Earth. White dwarfs are, as the name implies, small, typically only slightly bigger than Earth. If Jupiter were much larger, pressure would be great enough to have fusion happen in its core, which is a star. If you can't tell whether an object in the sky is a star or planet, you'll want to learn how to distinguish between the physical features of these two celestial bodies, and when it's best to view them. People are picking holes in this and I believe the premise is focusing on what we usually think of as main sequence stars, in which case, no they cannot. Normal stars (meaning ones that fuse hydrogen into helium in their cores) are much bigger than planets. They think that if it just formed from a cloud of gas, then it’s nothing more than a not-quite-star. So it's a little odd to think of a planet being bigger than a star, but we're not talking about a normal star here. I didn't see anyone answer the second part of your question. These two stars constitute a BY Draconis variable. Stars do the reverse, because as they get larger, their energy output increases, causing a star to puff up, but this particular star is just barely massive enough to fuse protium (the most common isotope of hydrogen), so its energy output is very low. Similar stories can be told about exoplanets residing in other stellar systems, where those stars can be hundreds of times larger than our Sun. I want to build a planet (or satellite) that: is smaller than Earth, has a thicker atmosphere than Earth but breathable, has neither intense volcanism, nor any extreme condition of that sort that would increase atmosphere density, revolves around a binary star similar to BY Draconis; A higher gravity makes for a higher atmosphere density. Of course a star is always much more massive than a planet, but in rare cases a star can be smaller than a giant planet. No. Regarding shape, stars appear as a dot while planets appear spherical. It orbits its star in only about 10 Earth-days. As the star is a white dwarf it didn't start out this way, the star would have been larger than the planet, but when it ended it's main sequence lifetime the star would have swelled into a giant, swallowing the planet. we'd have to look for stars right around the dividing line between Browns and Red Wolves to find the main sequence that small enough to host a larger planet. I would disagree with this as you are talking about a white dwarf which is a stellar remnant rather than what we typically call a star. As they get more massive they get denser but not bigger. share. "This planet probably does have liquid water," said David Charbonneau, a Harvard professor of astronomy and lead author of an article on the discovery. The short answer is “yes, it would be possible.” But as you might come to expect, the nitty-gritty details that make this statement true can become a bit more complicated than they seem and it has yet to be directly observed by astronomers today. More info at it's wikipedia page: https://en.wikipedia.org/wiki/WD_1856%2B534. Can a planet be bigger than its star? What I don't know is whether a Jupiter mass planet could form close enough to a star as massive as EBLM J0555-57Ab. If it was as big as a star, it would be big enough to cause fusion, since a star has to be that big. The leading scientific social networking website and producer of educational virtual events and webinars. Reactions: Labels: Astrum. The planet is rare, although astronomers don't know why planets orbiting evolved stars are so absent. Answer Save. Researchers have shown that it would need a reflective disc 19 times bigger than the Earth's diameter to achieve the orbital change over a timescale of one billion years. Others think that it can only be a planet if it formed around a star. 7 months ago. For a white dwarf, they are much denser and can be a couple of percent of the radius of the Sun. A smaller body always orbits around a larger body rather than the other way around because the larger body has more gravity. What is bigger than the Sun and all the planets yet lighter than air? Neutron stars however would be fairly easy to block out, even a large asteroid(>10 km) could completely cover it. 85 times as massive, to be exact. Favourite answer. If it was in an area of the universe where there was a significant amount of stray gas then it would attract it inwards, and I can't see why it couldn't have a few (cold and barren) planets. The planet's 50 times closer to the star than the Earth is the Sun, but it is as cool as Jupiter. Would it be torn apart by the tidal forces? These two riddles above can be solved by reading this article. A planet can only get so massive before it starts fusing its own atoms together, at which point it can't get any larger, just more dense. There are some exoplanets that are larger than Jupiter, but that's because they orbit much closer to their parent star than does Jupiter. Haven't even done orbital mechanics since undergrad, and I've gotten rusty. Our planet would also be made of the wrong stuff- White dwarfs (and thus, theoretically, black dwarfs) are made of Carbon and Oxygen- most stars aren't hot enough to fuse all the way to iron. Of course, that's pretty darned massive. On August 7, A SpaceX recovery vessel called GO Navigator brought the Crew Dragon capsule back to its home port. It will always be smaller than its star. Generally, stars are also bigger than planets. That's why the Earth lost any primordial hydrogen and helium envelope it might have had. you need a telescope to see some of the planets.a star twinkles.a planet glows. Don't know. The star is more than 50 times as dense as the Sun. Jupiter is about as big as a planet can be without becoming a star. The Goldilocks Zone is often referenced (an area around a planet’s host star which could be ‘just right’ for liquid water to exist) when it comes to habitability. yet, both stars and planets have different sizes, such as a white dwarf star is smaller than Jupiter. Posted by Danny Shook at July 18, 2020. And even if we were able to observe it, detecting the planet would be even more difficult. Earth is about the size of an average sunspot! A planet is a nearly spherical body which is in orbit around the Sun. The answer is, not likely. The center of mass between the planet and the star would, I think, be outside of the star, because the star is so very small, but the same is true of our sun and Jupiter, and the latter is still thought of as being in orbit around the Sun, because it move so much more than the Sun does. Volume-wise, they're much smaller than non-white dwarfs. When you look at the confines of our solar system and notice just how large the Sun is when compared to Jupiter, the largest planet in the solar system, it can be difficult to conceptualize an instance where a planet could possibly be bigger than its host star. Jupiter carries almost 318 times the mass of Earth, making the most massive planets possible the equivalent of nearly 3,200 Earths. Can a planet be bigger than its star? Yes, the largest exoplanets are larger than the smallest stars. Neutron stars aren't really stars. A planet orbits a star, and only a star. If the star that created those elements is still there when the planet is being formed, it is fully possible that the star has a smaller radius than the planet orbiting it (like a neutron star), but the star will also be much denser than the planet, ensuring that the centre of the orbit is nearer to the star than the planet. A star is what planets orbit around. Answer Save. Some moons can actually be smaller than some asteroids. Danny Shook “If you want to forget something or someone, never hate it, or never hate him/her. Remember the difference between a Brown Wolff and a main sequence star is whether the nuclear fusion takes place in the Stars Core, which we believe … I've read that it is possible for a planet to be bigger than a star, but is it possible for a planet to be bigger than the star it orbits? This way bigger than the most massive asteroid ever recorded, Ceres, which is … That being said, the planet would still need to be fairly large like Neptune or larger. Yes, a giant planet similar to Jupiter could be orbiting a neutron star (which is not much bigger than the Earth. More posts from the askastronomy community. Somebody else already mentioned the star EBLM J0555-57Ab, which has a radius only slightly in excess of that of Saturn (and less than that of Jupiter), https://earthsky.org/space/discovery-smallest-star-eblm-j0555-57ab. 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