HOME


DORADO

The Dolphinfish

dorado-whflower-1898 (57K)
Dorado (Dolphinfish) - Coryphaena hippurus - W. H. Flower - 1898

Dorado is a southern constellation not visible north of 16 degrees north latitude. It's title is the Latin name for the dolphinfish (Coryphaena hippurus), widely known as the mahi mahi, a large, predatory, blunt-nosed fish abundant in tropical waters, and prized for its flavourful meat. In life a brilliant rainbow of pastel greens, blues, and yellows, its skin quickly fades to a dull grey out of the water. Its figure was one of twelve southern constellations added by Dutch-Flemish astronomer, Petrus Plancius, and as you can see in the star chart below, the stars really do form the shape of this distinctive fish.

dorado-feb15-10pm-05north (55K)
Dorado - November 15, 10:00 PM - Latitude 5° North, Longitude 95° West





Stars of Dorado

Alpha Doradus (RA: 04h33m59.880s DE:-55°02'41.76")

There are no named stars in Dorado. Alpha Doradus is the luminary (brightest star) of the constellation at magnitude 3.27. It is a binary system about 170 light years away. The primary is an A0III blue/white giant, magnitude 3.8, and the companion is a B9V blue/white main sequence star, only slightly smaller and dimmer at magnitude 4.3. The pair are about one billion miles apart (9.7 AU), and orbit each other every 12 years.

dorado (52K)

Beta Doradus (RA: 05h33m37.520s DE:-62°29'23.19")

With an average magnitude of 3.76, Beta Doradus is the only other star in the constellation over fourth magnitude. It is classified as a Cepheid Variable, a star with regular luminosity shifts that can be used to calculate its size and distance. In this case the star is over a thousand light years away, and regularly changes from an F4 yellow supergiant with a magnitude of 3.45, to a G5 yellow giant with a magnitude of 4.50, and it does so every 9.842 days.

Planets of Dorado

Gliese 163 (RA: 04h09m16.0s DE:-53°22'23.00")

Dorado has four stars that we know support planets. Three of the stars are very far away and too dim to see with the naked eye, and host the usual unremarkable gas giant planets. One star however, is different. Designated Gliese 163, it is relatively close at a distance of 48.8 light years, and has three super earth planets just a few times larger than Earth.

Gliese 163 is an M3V red main sequence star, only half as hot as our Sun, which leaves it with a magnitude of only 11.81, despite its close proximity. The star's cool temperature of 3,500 degrees K also means the habitable zone for planets is much closer than with a hotter star like our Sun. The cool red sun of Gliese 163 has at least one super earth orbiting in the habitable zone, increasing the probability of life existing, and makes the Gliese system something to keep your eye on. For more information on these and other extrasolar planets, visit NASA's New Worlds Atlas, and The Open Exoplanets Catalogue.

dorado-gliese163 (97K)
Gliese 163 Planetary System - Artist Concept - NASA/JPL-Caltech

Deep Skies of Dorado

The Large Magellanic Cloud (05h23m 36.0s DE:-69°45'00")

Because Dorado is not visible north of 16 degrees north latitude, northern observers miss out on one of the most impressive sights in the night sky: the Large Magellanic Cloud (LMC). The LMC is an irregular dwarf galaxy considered to be a satellite of our much larger Milky Way Galaxy. The LMC is 14,000 light years across, and spills into the adjacent constellation of Mensa.

In the photo below, both the Large Magellanic Cloud and its smaller southern sibling the Small Magellanic Cloud are caught hanging in the predawn sky above the European Southern Observatory's Very Large Telescope (VLT) array, 8,500 feet (2,600 m) high in the Andean mountains. The LMC sits prominently in the upper left center, with the fainter SMC slightly lower in the right center of the image.

lmc-smc-horizon-eso-cr (153K)
Large and Small Magellanic Clouds - José Francisco Salgado, European Southern Observatory, Chile - December, 2010

The Large Magellanic Cloud is 160,000 light years away, making it one of the most distant objects visible with the naked eye. Still, it is relatively close as far as galaxies go, and is in fact the closest observable galaxy to Earth, providing a unique opportunity for astronomers to examine the dynamics at work inside a galaxy. The LMC has been studied closely, and much has been discovered, including 60 globular clusters, 400 planetary nebulae, and 700 open star clusters. The composite image below, compliments of the European Southern Observatory high in the Andes, is a small sampling of the treasures inside the LMC.

lmc-composite-eso-cr (323K)
Section of Large Magellanic Cloud - European Southern Observatory - June, 2010

NGC 2070 - The Tarantula Nebula (RA: 05h38m 36.0s DE:-69°06'00")

The largest and most impressive object inside the LMC is NGC 2070, The Tarantula Nebula, so conspicuous that until 1751 it was considered a star, and still carries the star designation of 30 Doradus. It is in fact an immense nebula, 1,000 light years across, filled with the fury and violence of star formation, safely 160,000 light years away. The nebula has an apparent magnitude of 8.0, and is a good target for a small scope.

ngc2070-tarantula-eso (375K)
NGC 2070 - The Tarantula Nebula - European Southern Observatory - June, 2010

Supernova Remnant SNR 0519-69.0 (RA 05h 19m 34.90s Dec -69º 02' 07.30")

Also inside the LMC is the supernova remnant SNR 0519-69.0, an expanding cloud of superheated gas caused by the explosion of a giant star.

dorado-SNR 0519-69.0-cr (235K)
SNR 0519-69.0 - Supernova Remnant - Hubble/Chandra Composite - January, 2015

The Dorado Group

NGC 1566 (RA: 04h20m00.0s DE:-54°56'00")

On the western side of the constellation is a cluster of far away galaxies known as the Dorado Group. The group contains about 70 galaxies 40 to 60 million light years away. The brightest of these is NGC 1566, a spiral galaxy about 40 million light years away with a magnitude of 9.7.

ngc1566-hubble-sm (266K)
NGC 1566 - Spiral Galaxy - Hubble Space Telescope - June, 2014

NGC 1672 (RA: 04h45m 42.0s DE:-59°15'00")

Almost as bright at magnitude 10.0 is barred spiral galaxy NGC 1672. Classified as a "Seyfert galaxy" with a hot, active nucleus, it is about 60 million light years away.

ngc1672-hubble-cr (134K)
NGC 1672 - Barred Spiral Galaxy - Hubble Space Telescope - April, 2007


cometarrowbpictor (2K) cometarrowfmensa (2K)
WINTER
Orion   Canis Major   Canis Minor   Lepus   Monoceros   Gemini   Taurus   Aries   Auriga   Camelopardalis  
Lynx   Eridanus   Columba   Caelum   Fornax   Phoenix   Horologium   Reticulum   Pictor   Dorado   Mensa   Hydrus  
SPRING
Ursa Major   Ursa Minor   Draco   Bootes   Canes Venatici   Coma Berenices   Virgo   Leo   Cancer  
Leo Minor   Sextans   Hydra   Crater   Corvus   Antlia   Pyxis   Puppis   Vela   Carina   Volans   Musca   Chamaeleon  
SUMMER
Cygnus   Lyra   Vulpecula   Sagitta   Aquila   Hercules   Corona Borealis   Ophiuchus   Serpens   Libra  
Scorpius   Sagittarius   Corona Australis    Telescopium   Ara   Norma    Centaurus   Lupus   Crux   Circinus   Triangulum Australe   Apus  
AUTUMN
Andromeda   Perseus   Cassiopeia   Cepheus   Pegasus   Cetus   Triangulum   Lacerta   Delphinus   Equuleus  
Scutum   Capricornus   Aquarius   Pisces   Sculptor   Piscis Australis   Microscopium   Grus   Indus   Tucana   Pavo   Octans  


contact (3K) copyright (2K)