Kappa Draconis is a
blue giantIn space sciences, a blue giant is a star with a spectral type of O or B and a luminosity class of III...
starA star is a massive, luminous ball of plasma that is held together by gravity. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth. Other stars are visible in the night sky, when they are not outshone by the Sun...
located in the
constellationIn modern astronomy, a constellation is an area of the celestial sphere, defined by exact boundaries.The term "constellation" can also be used loosely to refer to just the more prominent visible stars that seem to form a pattern in that area.-Definitions:...
DracoDraco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere...
. Its rarely used traditional name
KetuKetu is the descending lunar node.In Hindu mythology, Ketu is generally referred to as a "shadow" planet. It is believed to have a tremendous impact on human lives and also the whole creation. In some special circumstances it helps someone achieve the zenith of fame...
, meaning the Dragon's Tail, refers to the south lunar node according to the
Vedic/Hindu' is the Hindu system of astrology. Jyotisha is also known as Indian astrology, Hindu astrology, and Vedic astrology.
[Sutton, Komilla...]
lunar cycle.
At an
apparent magnitudeThe apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, normalized to the value it would have in the absence of the atmosphere...
of 3.88, it is barely visible to the
naked eyeThe naked eye is a figure of speech referring to human visual perception that is unaided by enhancing equipment, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
when artificial lighting from cities is present. Nevertheless, it is a powerful star, approximately five time as massive as the
SunThe Sun is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 99.86% of the Solar System's mass....
. It is approximately 490
light-yearAs defined by the International Astronomical Union , a light-year is the distance that light travels in a vacuum in one Julian year.The speed of light is 299,792,458 metres per second...
s away, and is 1,400 times brighter than the Sun.
Kappa is thought to be just entering its
red giantA red giant is a luminous giant star of low or intermediate mass that is in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
phase, having exhausted the supply of
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H
2...
in its
coreThe core of the Sun is considered to extend from the center to about 0.2 solar radius. It is the hottest part of the Solar System. It has a density of up to 150,000 kg/m³ and a temperature of close to 15,000,000 kelvins...
.
Kappa Draconis is a
blue giantIn space sciences, a blue giant is a star with a spectral type of O or B and a luminosity class of III...
starA star is a massive, luminous ball of plasma that is held together by gravity. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth. Other stars are visible in the night sky, when they are not outshone by the Sun...
located in the
constellationIn modern astronomy, a constellation is an area of the celestial sphere, defined by exact boundaries.The term "constellation" can also be used loosely to refer to just the more prominent visible stars that seem to form a pattern in that area.-Definitions:...
DracoDraco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere...
. Its rarely used traditional name
KetuKetu is the descending lunar node.In Hindu mythology, Ketu is generally referred to as a "shadow" planet. It is believed to have a tremendous impact on human lives and also the whole creation. In some special circumstances it helps someone achieve the zenith of fame...
, meaning the Dragon's Tail, refers to the south lunar node according to the
Vedic/Hindu' is the Hindu system of astrology. Jyotisha is also known as Indian astrology, Hindu astrology, and Vedic astrology.
[Sutton, Komilla...]
lunar cycle.
At an
apparent magnitudeThe apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, normalized to the value it would have in the absence of the atmosphere...
of 3.88, it is barely visible to the
naked eyeThe naked eye is a figure of speech referring to human visual perception that is unaided by enhancing equipment, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
when artificial lighting from cities is present. Nevertheless, it is a powerful star, approximately five time as massive as the
SunThe Sun is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 99.86% of the Solar System's mass....
. It is approximately 490
light-yearAs defined by the International Astronomical Union , a light-year is the distance that light travels in a vacuum in one Julian year.The speed of light is 299,792,458 metres per second...
s away, and is 1,400 times brighter than the Sun.
Kappa is thought to be just entering its
red giantA red giant is a luminous giant star of low or intermediate mass that is in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
phase, having exhausted the supply of
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H
2...
in its
coreThe core of the Sun is considered to extend from the center to about 0.2 solar radius. It is the hottest part of the Solar System. It has a density of up to 150,000 kg/m³ and a temperature of close to 15,000,000 kelvins...
. Over the next several thousand years, the star will expand, becoming more powerful but with a much cooler surface temperature. Tens of thousands of years from now, Kappa Draconis will appear much brighter, likely shining with a reddish hue.
The star is currently located at
declinationIn astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Dec is comparable to latitude, projected onto the celestial sphere, and is measured in degrees north and south of the celestial equator...
69° 47' 18" North (
RARight ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...
12h 33m 29.0s) , but due to the effects of
precessionPrecession refers to a change in the orientation of the rotation axis of a rotating body. It can be defined as a change in direction of the rotation axis in which the second Euler angle is constant...
, Kappa Draconis was the nearest star to the North Celestial Pole visible to the naked eye from 1793 BC to approximately 1000 BC. However, because it is so much dimmer than nearby
KochabBeta Ursae Minoris is the second brightest star in the bowl of the "Little Dipper,"the constellation Ursa Minor. It has the traditional name Kochab. Kochab's magnitude is 2.07. It is 16 degrees from Polaris. The star is an orange giant and is 126.4 ± 2.5 light years from Earth. It is 130 times...
, Kochab was considered the
pole starA pole star is a visible star, especially a prominent one, that is approximately aligned with the Earth's axis of rotation; that is, a star whose apparent position is close to one of the celestial poles, and which lies directly overhead when viewed from the Earth's North Pole or South Pole...
during that time instead.