Universe Guide

ET Draconis

ET Draconis Facts

ET Draconis's Alternative Names

HIP87311 is the reference name for the star in the Hipparcos Star Catalogue.

ET Draconis has alternative name(s) :- , ET Dra.

More details on objects' alternative names can be found at Star Names .

Location of ET Draconis

The location of the variable 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 ET Draconis, the location is 17h 50m 25.13 and +70° 45` 36.2 .

Radial Velocity and Proper Motion of ET Draconis

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 movements of these stars and are measured in milliarcseconds. The star is moving 20.53 ± 0.62 milliarcseconds/year towards the north and -3.76 ± 0.86 milliarcseconds/year east if we saw them in the horizon.

Radial Velocity

The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is -14.80 km/s with an error of about 0.60 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.

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 obtained as of 12th Feb 2017.

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Additional ET Draconis Facts and Figures

Visual Facts

Primary / Proper / Traditional NameET Draconis
Alternative NamesHIP 87311, ET Dra
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeVariable Star
GalaxyMilky Way
Absolute Magnitude 1.98 / 2.16
Visual / Apparent Magnitude9.70
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)17h 50m 25.13
Declination (Dec.)+70° 45` 36.2
Galactic Latitude30.51 degrees
Galactic Longitude101.28 degrees
1997 Distance from Earth2.86 Parallax (milliarcseconds)
 1140.43 Light Years
 349.65 Parsecs
2007 Distance from Earth3.10 Parallax (milliarcseconds)
 1052.14 Light Years
 322.58 Parsecs
 66,536,437.57 Astronomical Units
Proper Motion Dec.20.53 ± 0.62 milliarcseconds/year
Proper Motion RA.-3.76 ± 0.86 milliarcseconds/year
B-V Index1.14
Radial Velocity-14.80 ± 0.60 km/s

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeSemi-Regular Star w
Mean Variability Period in Days0.178
Variable Magnitude Range (Brighter - Dimmer)9.764 - 9.997

Sources and Links

SIMBAD SourceLink

Related Stars

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