The Royal Stars and History[edit]
The four stars with their modern and ancient Persian names were:
- Aldebaran (Tascheter) – vernal equinox (Watcher of the East)
- Regulus (Venant) – summer solstice (Watcher of the North)
- Antares (Satevis) – autumnal equinox
- Fomalhaut (Haftorang/Hastorang) – winter solstice (Watcher of the South)
The four dominant stars have an apparent magnitude of 1.5 or less.[4] The reason why they are called “Royal” is that they appear to stand aside from the other stars in the sky. The four stars, Aldebaran, Regulus, Antares, Fomalhaut, are the brightest stars in their constellations, as well as being part of the twenty five brightest stars in the sky, and were considered the four guardians of the heavens.[3] They marked the seasonal changes of the year and marked the equinoxes and solstices. Aldebaran watched the Eastern sky and was the dominant star in the Taurus constellation, Regulus watched the North and was the dominant star in the Leo constellation, Antares watched the West and was the alpha star in Scorpio, and Fomalhaut watched the Southern sky and was the brightest star in Piscis Austrinus (sharing the same longitude with the star Sadalmelik which is the predominant star in Aquarius). Aldebaran marked the vernal equinox and Antares marked the autumnal equinox, while Regulus marked the Summer Solstice and Fomalhaut the Winter Solstice. While watching the sky, the dominant star would appear in its season, each having a time of the year when most noticeable. Regulus was seen as the main star because it was in the constellation of Leo, giving it the power of the lion, signifying the strength of kings with large implications.[5]
The constellations of the Royal Stars were said to be fixed because their positions were close to the four fixed points of the sun’s path.[5] The sun was then surrounded by four bright stars at the beginning of every season.[6] From this observation individuals began to denote them the Royal Stars.[6]
By 700 BCE the Nineveh and Assyrians had essentially mapped the ecliptic cycle because of the four stars and were in result able to map the constellations, distinguishing them from the planets and the fixed stars.[5] From this, in 747 BCE the Babylonian King Nabu-nasir adopted a calendar derived from information based on the four stars, one following an eight-year cycle and one a nineteen-year cycle (later adopting the nineteen-year calendar as standard).[7]
The Royal Stars were used primarily for navigation.They were also believed to govern events in the world. Major disasters, breakthroughs, and historical phenomenons were seen as caused by the stars and their alignment in the sky during the time in which the event occurred.[5] When the stars were aligned accordingly, favourable conditions followed, and when they were negatively aligned, disaster was predicted. Because Regulus was the most influential of the Royal Stars, events that took place while Regulus was in dominance were amplified and grave, foreshadowing destruction.
Royal stars – Wikipedia, the free encyclopedia
Fomalhaut
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This article is about the star. For the extrasolar planet, see Fomalhaut b.
Fomalhaut
DSS image of Fomalhaut, field of view 2.7×2.9 degrees.
Credit NASA, ESA, and the Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)
Observation data
Epoch J2000 Equinox J2000
Constellation
Piscis Austrinus (Fomalhaut A+B), Aquarius (Fomalhaut C)
Fomalhaut
Right ascension
22h 57m 39.0465s[1]
Declination
−29° 37′ 20.050″[1]
Apparent magnitude (V)
1.16
TW Piscis Austrini
Right ascension
22h 56m 24.05327s[1]
Declination
−31° 33′ 56.0351″[1]
Apparent magnitude (V)
6.48[2]
LP 876-10
Right ascension
22h 48m 04.47s[3]
Declination
−24° 22′ 07.5″[3]
Apparent magnitude (V)
12.618[3]
Characteristics
Spectral type
A3 V / K5Vp / M4V[4][3]
U−B color index
0.08 / 1.02 / ?[5]
B−V color index
0.09 / 1.10 / 1.683[5][3]
Variable type
None / BY Draconis / ?
Astrometry
Fomalhaut
Radial velocity (Rv)
+6.5 km/s
Proper motion (μ)
RA: +328.95[1] mas/yr
Dec.: −164.67[1] mas/yr
Parallax (π)
129.81 ± 0.47[1] mas
Distance
25.13 ± 0.09 ly
(7.70 ± 0.03 pc)
Absolute magnitude (MV)
1.72[6]
TW Piscis Austrini
Radial velocity (Rv)
+6[2] km/s
Proper motion (μ)
RA: −331.11[1] mas/yr
Dec.: −158.98[1] mas/yr
Parallax (π)
131.42 ± 0.62[1] mas
Distance
24.82 ± 0.09 ly
(7.61 ± 0.04 pc)
Absolute magnitude (MV)
7.08[6]
Details
Fomalhaut
Mass
1.92±0.02[6] M☉
Radius
1.842±0.019[6] R☉
Luminosity
16.63±0.48[6] L☉
Surface gravity (log g)
4.21[7] cgs
Temperature
8,590[6] K
Metallicity [Fe/H]
−0.03[8] to −0.34[9] dex
Rotational velocity (v sin i)
93[7] km/s
Age
(4.4±0.4)×108[6] years
TW Piscis Austrini
Mass
0.725 ± 0.036[4] M☉
Radius
0.629 ± 0.051[4] R☉
Luminosity
0.19[6] L☉
Temperature
4,711 ± 134[4] K
Rotational velocity (v sin i)
2.93[4] km/s
Age
4.4 × 108[6] years
Other designations
Fomalhaut: α Piscis Austrini, α PsA, Alpha PsA, 24 Piscis Austrini, CPD −30° 6685, FK5 867, Gl 881, HD 216956, HIP 113368, HR 8728, SAO 191524
TW Piscis Austrini: Fomalhaut B, TW PsA, Gl 879, HR 8721, CD -32°17321, HD 216803, LTT 9283, GCTP 5562.00, SAO 214197, CP(D)-32 6550, HIP 113283
LP 876-10: Fomalhaut C, 2MASS J22480446-2422075, NLTT 54872, GSC 06964-01226
Database references
Fomalhaut
SIMBAD
data
Exoplanet Archive
data
ARICNS
data
Extrasolar Planets
Encyclopaedia
data
TW Piscis Austrini
SIMBAD
data
ARICNS
data
Fomalhaut (Alpha Piscis Austrini, Alpha PsA, α Piscis Austrini, α PsA) is the brightest star in the constellation Piscis Austrinus and one of the brightest stars in the sky. It is a class A star on the main sequence approximately 25 light-years (7.7 pc) from Earth as measured by the Hipparcos astrometry satellite.[10] Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.[11] It is classified as a Vega-like star that emits excess infrared radiation, indicating it is surrounded by a circumstellar disk.[12] Fomalhaut, K-type star TW Piscis Austrini and M-type star LP 876-10 constitute a trinary system.[13]
Fomalhaut holds a special significance in extrasolar planet research, as it is the center of the first stellar system with an extrasolar planet candidate (Fomalhaut b) imaged at visible wavelengths. The image was published in Science in November 2008.[14] Fomalhaut is the third brightest star known to have a planetary system, after Pollux and the Sun.
Contents
[hide]
Fomalhaut A[edit]
Dust ring around Fomalhaut from the Atacama Large Millimeter/submillimeter Array (ALMA)[15]
At a declination of −29.6°, Fomalhaut is located south of the celestial equator, and hence is best viewed from the Southern Hemisphere. However, its southerly declination is not as great as that of stars such as Acrux, Alpha Centauri and Canopus, meaning that, unlike them, Fomalhaut is visible from a large part of the Northern Hemisphere as well. Its declination is greater than that of Sirius and similar to that of Antares. At 40°N, Fomalhaut rises above the horizon for eight hours and reaches only 20° above the horizon, while Capella which rises at approximately the same time will stay above the horizon for twenty hours. From England the star never appears much brighter than magnitude 2.2 due to it being so close to the horizon, and from southern Alaska or Scandinavia it never rises above the horizon at all.[16] Fomalhaut can be located in these northern latitudes by the fact that the western (right-hand) side of the Square of Pegasus points to it. Continue the line from Beta to Alpha Pegasi towards the southern horizon: Fomalhaut is about 45˚ south of Alpha Pegasi, with no bright stars in between.[17]
Properties[edit]
The debris disk around the star
Fomalhaut is a young star, for many years thought to be only 100 to 300 million years old, with a potential lifespan of a billion years.[18][19] A 2012 study gave a slightly higher age of 440±40 million years.[6] The surface temperature of the star is around 8,590 K (8,320 °C). Fomalhaut’s mass is about 1.92 times that of the Sun, its luminosity is about 16.6 times greater, and its diameter is roughly 1.84 times as large.[6]
Fomalhaut is slightly metal-deficient as compared to the Sun, which means it is composed of a smaller percentage of elements other than hydrogen and helium.[7] The metallicity is typically determined by measuring the abundance of iron in the photosphere relative to the abundance of hydrogen. A 1997 spectroscopic study measured a value equal to 93% of the Sun’s abundance of iron.[8][nb 1] A second 1997 study deduced a value of 78% by assuming Fomalhaut has the same metallicity as the neighboring star TW Piscis Austrini, which has since been argued to be a physical companion.[6][20] In 2004, a stellar evolutionary model of Fomalhaut yielded a metallicity of 79%.[7] Finally, in 2008, a spectroscopic measurement gave a significantly lower value of 46%.[9]
Fomalhaut has been claimed to be one of approximately 16 stars belonging to the Castor Moving Group. This is an association of stars that share a common motion through space and have been claimed to be physically associated. Other members of this group include Castor and Vega. The moving group has an estimated age of 200±100 million years and originated from the same location.[18] Unfortunately more recent work that has found that purported members of the Castor Moving Group appear to not only have a wide range of ages, but their velocities are too different to have been possibly associated with one another in the distant past.[13] Hence, “membership” to this dynamical group has no bearing on the age of the Fomalhaut system.[13]
Amesbury in Wiltshire confirmed as oldest UK settlement
Amesbury – including Stonehenge – is the UK’s longest continually-occupied settlement
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A Wiltshire town has been confirmed as the longest continuous settlement in the United Kingdom.
Amesbury, including Stonehenge, has been continually occupied since 8820BC, experts have found.
The news was confirmed following an archaeological dig which also unearthed evidence of frogs’ legs being eaten in Britain 8,000 years before France.
Amesbury’s place in history has also now been recognised by the Guinness Book of Records.
David Jacques, from the University of Buckingham, said: “The site blows the lid off the Neolithic Revolution in a number of ways.
Historic Wiltshire
“It provides evidence for people staying put, clearing land, building, and presumably worshipping, monuments.
“The area was clearly a hub point for people to come to from many miles away, and in many ways was a forerunner for what later went on at Stonehenge itself.
“The first monuments at Stonehenge were built by these people. For years people have been asking why is Stonehenge where it is, now at last, we have found the answers.”
Mr Jacques said the River Avon, which runs through the area, would have been like an A road with people travelling along it.
“They may have had the equivalent of local guides and there would have been feasting,” he added.
“We have found remains of big game animals, such as aurochs and red deer, and an enormous amount of burnt flint from their feasting fires.”
The dig unearthed the largest haul of worked flints from the Mesolithic period
Previously, Thatcham in Berkshire, 40 miles from Amesbury, held the record for the longest continuous settlement in the country.
The dig in Amesbury also uncovered 31,000 worked flints in 40 days as well as animal bones such as frogs’ legs.
Mr Jacques said our ancestors were eating a “Heston Blumenthal-style menu”.
Amesbury facts
- Queen Eleanor of Provence – consort to Henry III – is buried at the town’s former abbey
- Amesbury residents get a free visitors’ pass to Stonehenge each year
- In 1965, the Beatles stayed at the Antrobus Arms Hotel whilst filming Help!
- The area’s most famous resident – Police frontman Sting – lives in nearby Wilsford cum Lake
The find was based on a report by fossil mammal specialist Simon Parfitt, of the Natural History Museum.
Andy Rhind-Tutt, the founder of Amesbury Museum and Heritage Trust, said there was “something unique and rather special about the area” to keep people there from the end of the Ice Age, to when Stonehenge was created and until today.
“The fact that the feasting of large animals and the discovery of a relatively constant temperature spring sitting alongside the River Avon, may well be it,” he said.
The dig was filmed and made into a documentary by the BBC, Smithsonian, CBC and others to be screened later in the summer.
The project was led by the University of Buckingham.
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broadcast nationwide from Monday, 29 April at 20:30 BST on BBC Four.
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