Universe Guide

HT Draconis

HT Draconis Facts

  • HT Draconis is a variable star that can be located in the constellation of Draco. The description is based on the spectral class.
  • HT Draconis is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (M...) of the star, the star's colour is red .
  • The star can not be seen by the naked eye, you need a telescope to see it.
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 1279.07 light years away from us. Distance

HT Draconis's Alternative Names

HIP94897 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD182075.

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

BD number is the number that the star was filed under in the Durchmusterung or Bonner Durchmusterung, a star catalogue that was put together by the Bonn Observatory between 1859 to 1903. The star's BD Number is BD+63 1510.

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

Location of HT 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 HT Draconis, the location is 19h 18m 41.03 and +63° 55` 17.4 .

Proper Motion of HT Draconis

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 1.64 ± 0.75 milliarcseconds/year towards the north and 2.23 ± 0.80 milliarcseconds/year east if we saw them in the horizon. . 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.

Physical Properties of HT Draconis

HT Draconis Temperature and Colour

Based on the star's spectral type of M... , HT Draconis's colour and type is red variable star. The star has a B-V Colour Index of 1.52 which means the star's temperature is about 3,971 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

HT Draconis Radius

HT Draconis estimated radius has been calculated as being 16.95 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 11,791,927.93.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 12.390639340529993320822170325. The figure is derived at by using the formula from SDSS rather than peer reviewed papers. It has been known to produce widely incorrect figures.

HT Draconis Apparent and Absolute Magnitudes

HT Draconis has an apparent magnitude of 8.98 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. If you used the 1997 Parallax value, you would get an absolute magnitude of 0.33 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.01. Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.

Distance to HT Draconis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 1.86000 which gave the calculated distance to HT Draconis as 1753.57 light years away from Earth or 537.63 parsecs. If you want that in miles, it is about 10,308,581,095,653,582.99, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 2.55000 which put HT Draconis at a distance of 1279.07 light years or 392.16 parsecs. It should not be taken as though the star is moving closer or further away from us. It is purely that the distance was recalculated.

Using the 2007 distance, the star is roughly 80,888,242.78 Astronomical Units from the Earth/Sun give or take a few. An Astronomical Unit is the distance between Earth and the Sun. The number of A.U. is the number of times that the star is from the Earth compared to the Sun.

Travel Time to HT Draconis

The time it will take to travel to this star is dependent on how fast you are going. U.G. has done some calculations as to how long it will take going at differing speeds. A note about the calculations, when I'm talking about years, I'm talking non-leap years only (365 days).

The New Horizons space probe is the fastest probe that we've sent into space at the time of writing. Its primary mission was to visit Pluto which at the time of launch (2006), Pluto was still a planet.

DescriptionSpeed (m.p.h.)Time (years)
Airbus A3807361,165,442,407.14
Speed of Sound (Mach 1)767.2691,117,946,393.84
Concorde (Mach 2)1,534.54558,972,468.40
New Horizons Probe33,00025,992,897.32
Speed of Light670,616,629.001,279.07
HT Draconis brightness ranges from a magnitude of 9.053 to a magnitude of 8.917 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.1 days (variability).

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.

Hide Explanations
Show GridLines

Additional HT Draconis Facts and Figures

Visual Facts

Primary / Proper / Traditional NameHT Draconis
Alternative NamesHD 182075, HIP 94897, BD+63 1510, HT Dra
Spectral TypeM...
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeVariable Star
GalaxyMilky Way
Absolute Magnitude 0.33 / 1.01
Visual / Apparent Magnitude8.98
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)19h 18m 41.03
Declination (Dec.)+63° 55` 17.4
Galactic Latitude21.29433792 degrees
Galactic Longitude94.99599099 degrees
1997 Distance from Earth1.86000 Parallax (milliarcseconds)
 1753.57 Light Years
 537.63 Parsecs
2007 Distance from Earth2.55000 Parallax (milliarcseconds)
 1279.07 Light Years
 392.16 Parsecs
 80,888,242.78 Astronomical Units
Proper Motion Dec.1.64000 ± 0.75000 milliarcseconds/year
Proper Motion RA.2.23000 ± 0.80000 milliarcseconds/year
B-V Index1.52

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Mean Variability Period in Days0.090
Variable Magnitude Range (Brighter - Dimmer)8.917 - 9.053

Estimated Calculated Facts

Radius (x the Sun)12.39
Effective Temperature3,971 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

There's no register feature and no need to give an email address if you don't need to. All messages will be reviewed before being displayed. Comments may be merged or altered slightly such as if an email address is given in the main body of the comment.

You can decline to give a name which if that is the case, the comment will be attributed to a random star. A name is preferred even if its a random made up one by yourself.

This website is using cookies. More info. That's Fine