400 ly
0a. Polaris Aa (α UMi Aa)
Size: 5.4 solar masses
Type: F7 yellow supergiant
Distance from Earth: 433 ly
Orbital period: under investigation
Near: under investigation
Location: under investigation
Polaris, designated α Ursae Minoris, is the brightest star in the constellation of Ursa Minor. It is very close to the north celestial pole, making it the current northern pole star.
Polaris is a triple star system, composed of the primary star, Polaris Aa (a yellow supergiant), in orbit with a smaller companion (Polaris Ab); the pair in orbit with Polaris B.
0b. Polaris Ab (α UMi Ab)
Size: 1.26 solar masses
Type: F6 main-sequence star
Distance from Polaris Aa: 18.8 AU
Orbital period: 29.59 years
1. Polaris B (α UMi B)
Size: 1.39 solar masses
Type: F3 main-sequence star
Distance from Polaris Aa: 2,400 AU
Orbital period: under investigation
600 ly
0. Helix Nebula (NGC 7293)
Size: 2.87 ly radius
Type: planetary nebula
Distance from Earth: 655±13 ly
Orbital period: under investigation
Near: under investigation
Location: under investigation.
one of the closest bright planetary nebulae to the Earth.
spans approx. 0.8 parsecs (2.5 ly).
inner disk: 0.52 pc in diameter.
outer torus: 0.77 pc in diameter.
outer-most ring: about 1.76 pc in diameter.
The Helix Nebula is a planetary nebula (PN) located in the constellation Aquarius. It is similar in appearance to the Cat's Eye Nebula and the Ring Nebula, whose size, age, and physical characteristics are similar to the Dumbbell Nebula, varying only in its relative proximity and the appearance from the equatorial viewing angle. The Helix Nebula has sometimes been referred to as the "Eye of God" in pop culture, as well as the "Eye of Sauron".
The Helix Nebula is a planetary nebula, formed by an intermediate to low-mass star that shed its outer layers near the end of its evolution. Gases from the star in the surrounding space appear—from our vantage point—as if we are looking down a helix structure. The remnant central stellar core, known as the central star (CS) of the planetary nebula, is destined to become a white dwarf star. The observed glow of the central star is so energetic that it causes the previously expelled gases to brightly fluoresce.
The Helix Nebula is thought to be shaped like a prolate spheroid with strong density concentrations toward the filled disk along the equatorial plane. We see the outer-most ring as flattened on one side due to its colliding with the ambient interstellar medium.
Expansion of the whole planetary nebula structure is estimated to have occurred in the last 6,560 years, and 12,100 years for the inner disk. Spectroscopically, the outer ring's expansion rate is 40 km/s, and about 32 km/s for the inner disk.
The main ring of the Helix Nebula contains cometary knots. These knots are radially symmetric (from the CS) and each is centered on a core of neutral molecular gas and containing bright local photoionization fronts—or cusps—towards the central star, and tails away from it. All tails extend away from the CS in a radial direction. Excluding the tails, each knot is approximately the size of the Solar system; while each of the cusp knots are optically thick due to Lyc photons from the CS. There are about 40,000 cometary knots in the Helix Nebula.
700 ly
0. Betelgeuse
Size: 11.6 solar masses
Type: red M1-2 supergiant
Distance from Earth: approx. 700 ly
Orbital period: under investigation
Near: under investigation
Location: under investigation
a pulsating star, so its diameter changes with time.
no definable "edge", as limb darkening causes the optical emissions to vary in color and decrease the farther one extends out from the center.
surrounded by a circumstellar envelope composed of matter ejected from the star—matter which absorbs and emits light.
Betelgeuse is a distinctly reddish semiregular variable star whose apparent magnitude has the widest range displayed by any first-magnitude star. At near-infrared wavelengths, Betelgeuse is the brightest star in the night sky.
Classified as a red supergiant, Betelgeuse is one of the largest stars visible to the naked eye; imagined as being at the center of the Solar System, its surface would lie beyond the asteroid belt and it would engulf the orbits of Mercury, Venus, Earth, Mars, and possibly Jupiter. Nevertheless, there are several larger red supergiants in the Milky Way. Calculations of Betelgeuse's mass range from slightly under ten to a little over twenty times that of the Sun.
Less than 10 million years old, Betelgeuse has evolved rapidly because of its large mass and is expected to end its evolution with a supernova explosion, most likely within 100,000 years. It is also surrounded by a complex, asymmetric envelope, roughly 250 times the size of the star, caused by mass loss from the star itself.
Having been ejected from its birthplace, this runaway star has been observed moving through the interstellar medium at a speed of 30 km/s, creating a bow shock over four light-years wide.
may lie ~2–3 AU above the photosphere
Molecular Environment (AKA MOLsphere)
The molecular layer—or molecular environment—is composed of water vapor and carbon monoxide, with an effective temperature of about 1500±500 K. The MOLsphere may also contain SiO and Al2O3, molecules which could explain the formation of dust particles.
extends ~10–40 AU from the photosphere
Gaseous Envelope
The asymmetric gaseous envelope is another cooler region. It is enriched in oxygen and especially in nitrogen relative to carbon.. It appears that several giant convection cells propel gas from the star's surface into its atmosphere.
average radius of ~10 to up to 200 AU
Chromosphere
The warm chromospheric plasma spatially overlaps and co-exists with cool gas in Betelgeuse's gaseous envelope, as well as with the dust in its circumstellar dust shells.
inner radius 100–200 AU
Dust Environment
Betelgeuse emits most of its excess radiation from positions beyond 50 to 60 AU, or roughly the distance of the Kuiper belt. The dust environment surrounding Betelgeuse is not static. The red supergiant undergoes sporadic decades long dust production, followed by inactivity. The dust shell is asymmetrically illuminated by a stellar radiation field strongly affected by the existence of photospheric hotspots.
A giant asymmetric dust shell was reported at 206,265 AU, and three dust shells were found extending four light-years from one side of the decaying star—suggesting that Betelgeuse sheds its outer layers as it moves.
S1 extends ~300 to 800 AU
S2 extends as far as ~1,400 AU
Two Outer Shells (S1 and S2)
Shells are composed of carbon monoxide (CO). The exact size of the two outer CO shells remains elusive. As the Sun's heliopause is estimated at about 100 AU, the size of this outer shell would be almost fourteen times the size of the Solar System.
estimated to be 1 parsec wide (3.26 ly)
Supersonic Bow Shock
Betelgeuse is travelling supersonically through the interstellar medium at ~6.3 AU/year, creating a bow shock. The shock is not created by the star, but by its powerful stellar wind as it ejects vast amounts of gas into the interstellar medium. The cometary structure is estimated to be at least one parsec wide.
The bow shock is very young—less than 30,000 years old—suggesting two possibilities: that Betelgeuse moved into a region of the interstellar medium with different properties only recently, or that Betelgeuse has undergone a significant transformation producing a changed stellar wind.
2600 ly
0. Deneb (α Cygni)
Size: 19±4 solar masses
Type: blue-white super giant
Distance from Earth: 2,615±215 ly
Orbital period: under investigation
Near: under investigation
Location: under investigation
Deneb is the brightest star in Cygnus, and the 19th brightest star in the night sky. Deneb rivals Rigel as the most luminous first magnitude star.
Deneb's absolute magnitude is among the visually brightest stars known, with an estimated luminosity nearly 200,000 solar luminosities. It is also the most distant of the 30 brightest stars by a factor of almost 2.
Based on its temperature and luminosity, and tiny angular diameter, Deneb appears to have a diameter of about over 200 times that of the Sun—if placed at the center of the Solar System, Deneb would extend out to the orbit of the Earth. It is one of the largest white 'A' spectral type stars known.
Stellar winds causes matter to be lost at 100,000 times the Sun's rate of mass loss, or equivalent to about one Earth mass per 500 years.
01. Deneb I
Size: under investigation
Type: rocky planet
Rotation: under investigation
Orbital period: under investigation
Atmosphere: under investigation
Water: under investigation
Orbit
under investigation
02. Deneb II
Size: under investigation
Type: rocky planet
Rotation: under investigation
Orbital period: under investigation
Atmosphere: under investigation
Water: under investigation
Orbit
under investigation
03. Deneb III
Size: under investigation
Type: rocky planet
Rotation: under investigation
Orbital period: under investigation
Atmosphere: under investigation
Water: under investigation
Orbit
under investigation
04. Deneb IV
Size: 1.25 Earth masses
Type: rocky planet
habitable planet orbiting Deneb.
Rotation: under investigation
Orbital period: under investigation
Atmosphere: standard
Water: under investigation
under investigation.
Civilian Govt.:
Pop.: under investigation
Local Gov.: under investigation
Main Leader(s): under investigation
Military:
Starport: under investigation
Top military leader: under investigation
Ship deployed in emergencies: under investigation
Settlements:
(Capital) under investigation
(2nd largest) under investigation
(3rd largest) under investigation
Rural Settlements
Small Cities: under investigation
Towns: under investigation
Villages: under investigation
Orbit
1 moon
Starbase: under investigation
04A Deneb IVa
Size: under investigation
Type: rocky satellite
Rotation: under investigation
Orbital period: under investigation
Atmosphere and water: under investigation
Surface:
under investigation
Orbit:
under investigation
05. inner asteroid belt
Estimated Size: under investigation
Type: asteroid belt
Orbital period: under investigation
Water: under investigation
06. Deneb V
Size: under investigation
Type: gas giant
Rotation: under investigation
Orbital period: under investigation
Atmosphere: under investigation
Water: under investigation
Orbit
under investigation
07. outer asteroid belt
Estimated Size: under investigation
Type: asteroid belt
Orbital period: under investigation
Water: under investigation
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