What type of stars are Castor and Pollux?
Pollux, at 33 light years distant, is an evolved red giant star twice as massive as our Sun. Castor, at 51 light years distant, is a blue main sequence star about 2.7 times more massive that our Sun.
Is Pollux A main sequence star?
Once an A-type main-sequence star, Pollux has exhausted the hydrogen at its core and evolved into a giant star with a stellar classification of K0 III.
Is Castor a double star?
Castor is three pairs of binary stars – six stars in all – in a complex dance around a common center of mass. Even a fairly small telescope will show Castor as two stars.
Are Castor and Pollux binary stars?
The stars Castor and Pollux are named for the twins of Greek mythology. Castor's combined apparent visual magnitude is 1.58. It appears as a bright visual binary, of which both members are spectroscopic binaries.
What are the 3 main sequence stars?
The majority of stars in the galaxy, including our Sun, Sirius and Alpha Centauri A and B are all main sequence stars.
What are the 2 main sequence stars?
A main sequence star is any star that has a hot, dense core which fuses hydrogen into helium to produce energy. Most stars in the galaxy are main sequence stars, including Alpha Centauri A, Tau Ceti and the Sun.
What type of star is the Castor star?
dwarf starsCastor C is a variable star, classified as a BY Draconis type. BY Draconis variables are cool dwarf stars which vary as they rotate due to starspots or other variations in their photospheres. The two red dwarfs of Castor C are almost identical, with masses around a half M ☉ and luminosities less than 10% of the Sun.
What star Class is Castor?
Castor ASpectral classA1V + dM1eMetallicity (α Gem Aa)0.98 dexAge370 million yearsRotational velocity (α Gem Aa)18 km/sSurface gravity (α Gem Aa)4.2 cgs11 more rows•Sep 16, 2019
What is Castor known for?
Definition. Castor and Pollux (the Dioscuri) are figures from Greek and Roman mythology considered the twin sons of Zeus or Jupiter. Semi-divine figures, they were credited with the role of saving those in trouble at sea or in grave danger in war and were particularly associated with horses and sports.
What are the 4 different types of binary stars?
What are the different types of binary star system?Visual binaries.Spectroscopic binaries.Eclipsing binaries.Astrometric binaries.
What is the difference between Castor and Pollux?
Their mother was Leda, but they had different fathers; Castor was the mortal son of Tyndareus, the king of Sparta, while Pollux was the divine son of Zeus, who raped Leda in the guise of a swan. The pair are thus an example of heteropaternal superfecundation.
How were Castor and Pollux different?
The constellation of Gemini is made up of two twins: Castor and Pollux. Castor was the mortal son of King Tyndarus, while Pollux was the immortal son of Zeus. Both Castor and Pollux, being identical twins, were inseparable in their looks and actions. Castor was great horseman and Pollux was a great fighter.
What is a main sequence in stars?
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell.
Is Zeta Puppis A main sequence star?
These stars are quite massive (15 – 90 M☉ on the main sequence) and have mass loss rates of over a millionth solar masses per year. (In comparison, the Sun sheds 10 million times less over the same period.) Like other class O stars, Naos is losing mass through an exceptionally strong stellar wind.
Is Pollux a multiple star system?
Pollux is a single star — a bloated giant near the end of its life. Castor, on the other hand, is a system of six stars — one of only a dozen or so known sextuple stars. Two of its stars are bigger, brighter, and heavier than the Sun.
What is Pollux known for?
Pollux and Castor were also known for their boxing abilities and were thus the gods of athletes and athletic competitions. In both art and literature, Pollux and his brother were shown with horses, as the two were famed horsemen.
What is the name of the star in the calendarium of Al Achsasi Al Mouakket?
In the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, this star was designated Aoul al Dzira, which was translated into Latin as Prima Brachii , meaning the first in the paw.
What is the WGSN?
In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Castor for the star α Geminorum Aa.
How many stars are in a castor?
Stellar system. Castor is a multiple star system made up of six individual stars; there are three visual components, all of which are spectroscopic binaries.
What is the name of the star system that is made up of three binary pairs?
It has the Bayer designation α Geminorum, which is Latinised to Alpha Geminorum and abbreviated Alpha Gem or α Gem. It appears singular to the naked eye, but it is actually a sextuple star system organized into three binary pairs, made up of the stars Castor Aa, Castor Ab, Castor Ba, Castor Bb, Castor Ca, and Castor Cb.
When do stars set in the constellation?
Stars that can set (not in a circumpolar constellation for the viewer) culminate at midnight – noticeable where viewed away from any polar region experiencing midnight sun – when at opposition, meaning they can be viewed from dusk until dawn. This applies to α Geminorum on 14 January, in the current astronomical epoch.
When was Castor first seen as a double star?
Appearing to the naked eye as a single star, Castor was first recorded as a double star in 1718 by James Pound, but it may have been resolved into at least two sources of light by Cassini as early as 1678.
Is Castor C a red dwarf?
The two red dwarfs of Castor C are almost identical , with masses around a half M☉ and luminosities less than 10% of the Sun.
How many stars are in the Castor system?
Telescopic observations of Castor began to reveal a more complicated story of the single star. Today, NASA says the system is made up of six stars:
What constellation is Castor in?
Castor: The Sextuplet Set of Stars. Castor is a bright star in the constellation Gemini that, along with Pollux, is one of the two main guideposts for the asterism that is sometimes nicknamed "The Twins.". At magnitude 1.58, Castor is the 20th brightest star in Earth's night sky. It is also relatively close to the planet, ...
What is the meaning of the name Castor?
Castor and Gemini in mythology and history. The name "Castor" flows from Greek and Latin mythology (the name is Latin, while the mythology is from both cultures). According to legend, Castor and his brother, Pollux, were both believed to be twin gods who assisted sailors who were shipwrecked, and who also were willing to entertain gifts ...
How far is Castor from Earth?
At magnitude 1.58, Castor is the 20th brightest star in Earth's night sky. It is also relatively close to the planet, at an estimated distance of 51 light-years from Earth. A closer examination of the star with a telescope actually reveals it is made up of many. What naked-eye observers see as Castor is actually the combined light of six stars, ...
What is the name of the pair of stars that whip around each other?
A pair of stars just south of the Castor AB complex, called YY Gem. This is also a binary system with two dwarfs that whip in their respective orbits around each other every 19 hours.
What telescopes are used to see binary stars?
In 2000, the European Space Agency's XMM-Newton orbiting telescope' s EPIC camera revealed that these binary stars are also large sources of X-rays with temperatures in the millions of degrees, NASA stated.
How many stars are in the sextuplet?
Castor the sextuplet. Telescopic observations of Castor began to reveal a more complicated story of the single star. Today, NASA says the system is made up of six stars: A pair of stars just south of the Castor AB complex, called YY Gem.
Bright shining star
More than 2,000 years ago, the Greek astronomer Hipparchus was the first to make a catalog of stars according to their brightness, according to astronomer-cum-software developer Dave Rothstein, who graduated from Cornell University with a PhD in Philosophy and an MS in Astronomy, in 2007.
When the stars go out
Eventually, a main sequence star burns through the hydrogen in its core, reaching the end of its life cycle. At this point, it leaves the main sequence.
Additional resources
Learn more about the life cycles of stars and what happens to different stars and their fates on NASA's Science Mission Directorate.
Bibliography
J. W. Blackman, J. P. Beaulieu, D. P. Bennett, C. Danielski, C. Alard, A. A. Cole, A. Vandorou, C. Ranc, S. K. Terry, A. Bhattacharya, I. Bond, E. Bachelet, D. Veras, N. Koshimoto, V. Batista & J. B. Marquette, Nature.com, " A Jovian analogue orbiting a white dwarf star "
What constellation is Castor?
Castor is a A2VM main sequence star based on the spectral type that was recorded in the Hipparcos star catalogue. Castor is a main star in the constellation Gemini and makes up the constellation outline. Based on the spectral type (A2Vm) of the star, the star's colour is blue - white .
How big is the radius of a star?
The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,974,647.80.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 2.81. The figure is derived at by using the formula from SDSS rather than peer reviewed papers. It has been known to produce widely incorrect figures.
What is the amount of energy that a star pumps out?
Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 53.40 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.
What is the temperature of a star?
Based on the spectral type, we can deduce that the surface temperature of the star is in the order of between 7,500 and 10,000K based on the notes from Harvard University. To put this in context, the temperature of our Sun is about 5,778 Kelvin as said by Google.
How many stars are in Castor?
Castor is one of the larger Multiple Star System so far discovered with six stars. The system is only beaten by Jabbah in the constellation of Scorpius and AR Cassiopeiae in the constellation of Cassiopeia which each of them have seven stars. The format of the star system is below. It is not drawn to scale, just drawn to illustrate. You will notice that there are no central main star, they operate a three pairs of Binary Star System moving around a central point of Gravity.
How far is a star from the Sun in 2007?
Using the 2007 distance, the star is roughly 3,217,708.56 Astronomical Units from the Earth/Sun give or take a few. An Astronomical Unit is the distance between Earth and the Sun. The number of A.U. is the number of times that the star is from the Earth compared to the Sun.
What is the lowest magnitude of a star?
Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.
What is the temperature of Castor C?
Based on the star's spectral type of M0.5VeFe-2 C , Castor C's colour and type is red main sequence star. Based on the spectral type, we can deduce that the surface temperature of the star is in the order of between below 3,500K based on the notes from Harvard University. To put this in context, the temperature of our Sun is about 5,778 Kelvin as said by Google.
How to determine the location of a star in the night sky?
The location of the main sequence star in the night sky is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth. The Right Ascension is how far expressed in time (hh:mm:ss) the star is along the celestial equator. If the R.A. is positive then its eastwards. The Declination is how far north or south the object is compared to the celestial equator and is expressed in degrees. For Castor C, the location is 07h 34m 37.584 and +31 ° 53` 17.81 .
What is the main sequence star of the constellation C?
Castor C is a Main Sequence Star type star. Castor C is a M0.5VEFE-2 C main sequence star based on the spectral type that was recorded in Simbad at Strasbourg University.
What is the lowest magnitude of a star?
Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.
What is a star rotating by Draconis?
The star is a rotating BY Draconis variable type which means that its size changes over time. The Variable Type is usually named after the first star of that type to be spotted.
What is the speed at which the stars are moving away from the Sun?
The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is 2.50000 km/s . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its nothing to fear as the stars are so far apart, they won't collide in our life-time, if ever.
What are the names of the twins in the constellation of Gemini?
The stars Castor and Pollux in Gemini, the zodiac’s most northerly constellation, present a striking sight in the night sky, and have been included in many legends across the world. In ancient Greece, for instance, they represented the twin son’s of Queen Leda of Sparta, with Pollux being the immortal offspring of the adulterous Zeus, while his brother Castor was the son of King Tyndareus, and therefore moral. Together the twins were inseparable, and their many adventures were legendary, including joining Jason and the Argonauts on their quest to find the Golden Fleece.
What is the name of the star that marks out the heads of the Heavenly Twins?
Castor (Alpha Geminorum) is the “other” star that marks out the “heads” of the Heavenly Twins in the constellation Gemini, the other being Pollux (Beta Geminorum). Even though Castor is the least luminous of the pair and only the 23rd brightest star in the night sky, compared to the 17th brightest for Pollux, it still revels in being assigned the constellation’s “alpha” designation . Another distinction between the two stars is that while Pollux is a single star, Castor , on the other hand, is a multiple star system consisting of three spectroscopic binary pairs of stars.
How many light years does Castor A and B orbit each other?
All three visual components of the Castor system are in fact close spectroscopic binaries, with Castor A and B separated by an average of 104 AU, or 15 light years, and orbiting each other every 445 years, while Castor C is separated from the principal Castor AB pair by a distance of about 1000 AU, and orbits them over a 14,000 year period. In terms of the three individual systems, Castor A and B have fainter companions which orbit them over a few days, while Castor C has a companion with an orbital period of less than a day.
Why does Castor C have different luminosities?
Interestingly, the regular variations in the luminosity of Castor C was at first thought to be the result of the two stars eclipsing each other, but recent studies are suggesting that these variations are caused by areas on the surface of one (or perhaps both stars) that have different luminosities. As a result, Castor C now has the variable star designation YY Geminorum.
What are the properties of the two main sequence stars?
The two principal pairs of stars each consist of a hot A-type main sequence star, that are both more massive and luminous than the Sun , and a cool red dwarf, whose physical properties are difficult to determine given their close proximity to their primaries, although the dwarfs are thought to be only about 50% as massive as the Sun. By contrast, the two red dwarfs that make up Castor C are almost identical, each having about 50% of the Sun’s mass, giving them luminosities of around 10% (or less) that of the Sun. It is worth noting though that all four red dwarfs in the Castor system show strong emission lines in their spectra, and that all four dwarfs are flare stars, which are a class of variable stars that exhibit sudden and dramatic fluctuations in brightness over periods of only a few minutes.
Where can I see Gemini?
The constellation of Gemini can be seen from between latitudes of +90° and -60°, where it occupies an area of 514 square degrees of the northern skies . Observers from mid-northern latitudes can observe Gemini, and by extension, both Castor and Pollux, from January to around the beginning of May relatively high in the sky. By late May, or the beginning of June, Gemini has sunk low over the west-north-western horizon just after sunset, and at around the time of the summer solstice on June 21st, both Castor and Pollux become difficult to spot after sunset. The best time to view Gemini and its two brightest stars is in January and February, when the Twins stand virtually upright at around 5 A.M. Local Time. Note however that the constellation sets two hours earlier every month after February.
Who was the head of the foremost twin?
Elsewhere around the world, Castor was known to the Arabs as Al-Ras al-Taum al-Muqadim, meaning “the head of the foremost twin”, although a later catalogue compiled by Egyptian astronomer Al Achsasi al Mouakket called the Calendarium listed Castor as ”Aoul al Dzira”, or “the first in the paw”.
How do main sequence stars work?
All main sequence stars are in equilibrium, meaning the outward pressure caused by the fusion reactions is balanced by the force of gravity pulling the star together. The pressure and temperature of a main sequence star increase as you get closer to its center. The length of time that a star spends at this stage in its life depends on how much mass the star has. Counterintuitively, massive stars have a shorter lifespan than smaller stars. Large, massive stars use up their nuclear fuel at a much faster rate than smaller stars. Stars can range in size from about a tenth of the size of our sun all the way up to hundreds of times as big. The color of a star also varies depending on its size. Larger stars are hotter and they emit more blue light; smaller stars are smaller and emit more red light.
What is the main sequence of a star?
A main sequence star is a star in the stable part of its life cycle. They are the most common type of star in the universe. Our star, the Sun, is in the main sequence phase. It is about halfway through this stage, and ultimately will become a red giant in roughly five billion years.
Which type of star is the most stable?
Main sequence stars are the most common type in the Universe. Main sequence stars are stable. They fuse hydrogen nuclei together to form helium nuclei, releasing energy and emitting light.
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Overview
Physical properties
Castor is 51 light-years away from Earth, determined from its large annual parallax.
The two brightest stars are both A-class main-sequence stars, more massive and brighter than the Sun. The properties of their red dwarf companions are difficult to determine, but are both thought to have less than half the mass of the Sun.
Stellar system
Castor is a multiple star system made up of six individual stars; there are three visual components, all of which are spectroscopic binaries. Appearing to the naked eye as a single star, Castor was first recorded as a double star in 1718 by James Pound, but it may have been resolved into at least two sources of light by Cassini as early as 1678. The separation between the binary systems Castor A and Castor B has increased from about 2″ (2 arcseconds of angular measurement) in 1970 to a…
Etymology and culture
α Geminorum (Latinised to Alpha Geminorum) is the star system's Bayer designation.
Castor and Pollux are the two "heavenly twin" stars that give the constellation Gemini (meaning twins in Latin) its name. The name Castor refers specifically to Castor, one of the twin sons of Zeus and Leda in Greek and Roman mythology.
The star was annotated by the Arabic description Al Ras al Taum al Muqadim, which translates a…
Long-exposure observation
Stars that can set (not in a circumpolar constellation for the viewer) culminate at midnight – noticeable where viewed away from any polar region experiencing midnight sun – when at opposition, meaning they can be viewed from dusk until dawn. This applies to α Geminorum on 14 January, in the current astronomical epoch.
See also
• List of brightest stars
• List of nearest bright stars
• Historical brightest stars
External links
• Media related to Castor (star) at Wikimedia Commons
• "Castor 6". SolStation. Retrieved December 5, 2005.
Information on Castor
- Although the star is referred to as the Alpha star in the constellation, it is not as bright as its twin, Polluxwhich is a yellow supergiant. Although it is not as bright as it twin, it has the Bayer classiification of Alpha Geminorum. This is probably done to an error in identify which star was brighter. The twin star is Pollux, they are not close...
Castor Location
- The location of the main sequence star in the night sky is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth. The Right Ascension is how far expressed in time (hh:mm:ss) the star is along the celestial equator. If the R.A. is positive then its eastwards. The Declination is how far north or south the o…
Castor Radial Velocity and Proper Motion
- Castor Proper Motion
All stars like planets orbit round a central spot, in the case of planets, its the central star such as the Sun. In the case of a star, its the galactic centre. The constellations that we see today will be different than they were 50,000 years ago or 50,000 years from now. Proper Motion details the … - Castor Radial Velocity
The Radial Velocity, that is the speed at which the star is moving away the Sun is 5.40000 km/s with an error of about 0.50 km/s . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its not…
Castor Physical Properties
- Castor Colour
Based on the star's spectral type of A2Vm , Castor's colour and type is blue - white main sequence star. There is no relationship between colour and size, a red star can be both the largest and the smallest stars in the Universe. Small stars are more energy efficient than larger s… - Castor Temperature
Based on the spectral type as we don't have the exact temperature', we can deduce that the surface temperature of the star is in the order of 7,500 and 10,000K based on the notes from Harvard University. To put this in context, the temperature of our Sun is about 5,778 Kelvin as s…
Castor Apparent (Brightness) and Absolute Magnitudes
- Absolute Magnitude is the apparent magnitude of the star from a distance of 10 parsecs or 32.6 light years. This assumes that there is nothing in between the object and the viewer such as dust clouds. To really compare the brightness of the star, it is best to use Absolute rather than Apparent Magnitude. Magnitude, whether it be apparent/visual or absolute magnitude is measur…
Castor Distance from Earth
- Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 63.27000 which means Castor distance from Earth is 51.55 light years away from Earth or 15.81 parsecs. If you want that in miles, it is about 303,043,137,987,615.096, based on 1 Ly = 5,878,625,373,183.61 miles. In 2007, Hipparcos data was revised with a new parallax of 64.1200…
Alternative Names and Meanings
- The Id of the star in the Yale Bright Star Catalogue is HR2891.
- HIP36850 is the reference name for the star in the Hipparcos Star Catalogue.
- The Id of the star in the Henry Draper catalogue is HD60179. The catalogue was started by the American doctor and has been expanded on over the years.
- The Gliese ID of the star is GL 278.0. The star was part of the original catalogue devised by …
- The Id of the star in the Yale Bright Star Catalogue is HR2891.
- HIP36850 is the reference name for the star in the Hipparcos Star Catalogue.
- The Id of the star in the Henry Draper catalogue is HD60179. The catalogue was started by the American doctor and has been expanded on over the years.
- The Gliese ID of the star is GL 278.0. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Star Names
Castor Travel Time
- The time it will take to travel to this star is dependent on how fast you are going. U.G. has done some calculations as to how long it will take going at differing speeds. A note about the calculations, when I'm talking about years, I'm talking non-leap years only (365 days). The New Horizons space probe is the fastest probe that we've sent into space at the time of writing. Its pri…
Meteor Showers Radiating Near Castor
- The GeminidsMeteor Shower radiants from a point near this star. The meteor shower runs typically between December 6-19 with a peak date of 14th Dec.. The speed of a meteor in the shower is 34 Km/s. The amount of meteors predicted to be seen per hour (Zenith Hourly Rate) is 34.
Source of Information
- The source of the information if it has a Hip I.D. is from Simbad, the Hipparcos data library based at the University at Strasbourg, France. Hipparcos was a E.S.A. satellite operation launched in 1989 for four years. The items in red are values that I've calculated so they could well be wrong. Information regarding Metallicity and/or Mass is from the E.U. Exoplanets. The information was …