have scientist found out how many planets are in our nearest solar system?

Question

by the way what is our nearest solar system?
which constellation is it in?
how big is its sun??

ALSO WHEN WE VIEW SOMETHING THAT IS LIGHT YEARS AWAY, ARE WE REALLY LOOKING AT AN IMAGE 1000'S OF YEARS AGO?
HOW DO WE EVEN KNOW IF THAT STAR EVEN STILL EXISTS??

Answer 1

There are currently 212 known exoplanets. The nearest star with one such planet is Epsilon Eridani just over 10 light years away but the nearest star with 2 or more such planets is Gliese 876, 15 light years away

Only 20 stars are known to have more than one such planet and the highest number any one star is known to have is four, There are 48 known planets in 20 multiple-planet systems (14 with two planets, 4 with three and 2 with four).

STARS WITH FOUR KNOWN PLANETS

55 Cancri A (spectral type G8 V) (magnitude 5.95) is a binary star located around 40 light-years away in the constellation Cancer. The system contains a yellow dwarf star (55 Cancri A) similar to our Sun and a red dwarf (55 Cancri B). The two components are separated by over 1000 times the distance from the Earth to the Sun.

As of 2004, four extrasolar planets are known in orbit around 55 Cancri A. Three of the planets are comparable to Jupiter in mass, while the innermost planet has a mass similar to that of Neptune. The 55 Cancri system was the first known four-planet extrasolar planetary system. The planets have orbital periods of 2.81 days, 14.67 days, 43.93 days and 4517.4 days.

Mu Arae (spectral type G3 IV–V and magnitude 5.12) ) is a Sunlike yellow-orange star located around 50 light years away in the constellation Ara. The star has a planetary system with four known planets. The system's innermost planet was the first "hot Neptune" to be discovered.

The planets have orbital periods of 9.6386 days, 310.55 days, 643.25 days and 4205.8 days.

STARS WITH THREE KNOWN PLANETS

Upsilon Andromedae A is a binary star, approximately 44 light-years away in the constellation Andromeda. The system contains a yellow-white dwarf star (Upsilon Andromedae A) similar to the Sun (spectral type F8 and magnitude 4.09) and a dim red dwarf (Upsilon Andromedae B). The two stars are separated by around 750 times the distance from the Earth to the Sun.

Three extrasolar planets are known in orbit around Upsilon Andromedae A. All three are comparable to Jupiter in mass. Upsilon Andromedae was both the first multiple-planet planetary system to be discovered around a main sequence star, and the first multiple-planet system known in a multiple star system.

HD 37124 is a yellow dwarf star (spectral type G4 IV-V) in the constellation of Taurus. It is 108 light years from Earth and has three extrasolar planets. They have orbital periods of 154.46 days, 843.6 days and 2295 days

HD 69830 (spectral type K0 V) is an orange dwarf star (magnitude 5.95) approximately 41 light-years away in the constellation Puppis. It has three known Neptune-sized planets. They have orbital periods of 8 days, 31 days and 197 days.

In 2005, the Spitzer Space Telescope detected dust in the HD 69830 system consistent with the existence of an asteroid belt twenty times more massive than that in our own system lying inside an orbit equivalent to that of Venus in our own solar system.

The belt would be so massive that the nights on any nearby planets would be lit up by zodiacal light 1000 times brighter than that seen on Earth, easily outshining the Milky Way.

Gliese 876 is a red dwarf star (spectral type M3.5 V and magnitude 10.16) located approximately 15 light-years away in the constellation Aquarius. As of 2006 the star is known to host three extrasolar planets, including one with a mass less than half that of Neptune with orbital periods of 1.93 days, 30.34 days and 60.94 days.

For a complete list of the 212 exoplanets see the first link.

Answer 2

New planets are being spotted all the time. When I say spotted, I don't mean that they can be seen - but they can be detected by the "wobble" effect they have on the star they are orbitting

I'm not sure that they've yet discovered an actual solar system - or if they have, that they know too much about it. Shouldn't think it'll be long before they do though.

Yes, the light you see from distant stars is very old. If the star is, say, 400 light years away - that means it would have taken 400 years for the light to reach us - so we're seeing it now as it would have been 400 years ago. We're looking into the past in other words. In fact, some of the stars we can see in the sky may no longer exist at all.

Answer 3

Epsilon Eridani is the nearest Star with a satellite planet.
It is smaller than our own Sun and is in the constellation Eridani

It is the third closest star outside of the solar system visible without a telescope. It has 85% of the Sun's mass, is roughly the same size, but has only 28% of its luminosity, and is 10.522 light years distant.

Many attempts to search for orbiting planets have been made. However, the star's high activity and variability means that finding planets with the radial velocity method is difficult, and stellar activity may mimic the presence of planets.

Observations by the Hubble Space Telescope have confirmed the existence of this planet. The estimated mass is 1.5 times Jupiter's mass, and the orbit is inclined by an angle of 30° from our line of sight. This orbital inclination is parallel to the observed dust ring around the star. The planet is expected to reach periapsis in 2007, when it could potentially be observed by the Hubble telescope.

NASA SIM PlanetQuest project, scheduled for launch within the next decade, will be the most powerful planet-hunting space telescope ever devised. Using two separated mirrors and combining their light with a technique known as interferometry, SIM PlanetQuest will able to detect planets as small as Earth. These are the kind of planets that scientists believe have the most potential to support life.

Answer 4

The nearest star is Proxima Centauri:
http://en.wikipedia.org/wiki/Proxima_centauri
followed by Alpha and Beta Centauri:
http://en.wikipedia.org/wiki/Alpha_Centauri
The three stars are considered to be part of the Alpha Centauri system.

While there's some possibility of planets, none have been found, but that doesn't mean they're not there.

Star light is indeed old, and there's no certainty that the stars are in the same condition as it's older light shows, but, from previous study, astronomers can determine rough age and some probabilty of whether the star is currently still in existence.

Answer 5

Epsilon Eridani is the nearest Star with a satellite planet.
It is smaller than our own Sun and is in the constellation Eridani

It is the third closest star outside of the solar system visible without a telescope. It has 85% of the Sun's mass, is roughly the same size, but has only 28% of its luminosity, and is 10.522 light years distant.

Hope this helps

Answer 6

It is possible for all stars to have planets, if they were small rocky planets such as our earth, it would be impossible to detect them, it is therefore not possible to know how many planets the nearest star with planets has. All stars are light years away from us, that means it takes the light they emit a number of years to reach us, we would not know if they went nova for years after the event, in most cases that would be longer than a human lifetime. However the chance of them all having gone nova is very small. Not all stars are capable of going nova, these will doubtless still be there.

Answer 7

Sorry, I don't know what the nearest solar system is or how big the sun is, but I'm fairly sure it's in our galaxy. And no, they haven't found all the planets. The most common method of locating planets elsewhere is by observing them in transit across their own sun. Which means that it's usually the large planets that get discovered.

Answer 8

The closest star known to have planets is Epsilon Eridani, in the constellation Eridanus. That star is about 10 light years away and is slightly smaller than our Sun. Only one planet is known to orbit that star, so I suppose it is safe to assume we have not detected them all.

Answer 9

There are hot debates going on about our own solar system. If we are not yet able to decide/find all planets in our own neighborhood, how could we decisively find about other stars ?

Answer 10

People are trying to find another Solar System which may even have life, but at the moment, I have not kept up to date. But, they usually find large planets first.