Universe Guide

ER Boötis

ER Boötis Facts

  • ER Boötis is a variable star that can be located in the constellation of Bootes. The description is based on the spectral class.
  • ER Boötis is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (M0) 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.
  • The star is calculated at being about -856.07 light years away from us. Distance

ER Bootis's Alternative Names

HIP72838 is the reference name for the star in the Hipparcos Star Catalogue.

ER Bootis has alternative name(s) :- , ER Boo.

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+36 2544.

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

Location of ER Boötis

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 ER Boötis, the location is 14h 53m 17.99 and +35° 53` 44.8 .

Physical Properties of ER Boötis

ER Bootis Temperature and Colour

Based on the star's spectral type of M0 , ER Bootis'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.

ER Bootis Radius

ER Boötis Apparent and Absolute Magnitudes

ER Boötis has an apparent magnitude of 9.85 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. Using the supplied Parallax value, you would get an absolute magnitude of 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 ER Boötis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as -3.81000 which gave the calculated distance to ER Boötis as -856.07 light years away from Earth or -262.47 parsecs. If you want that in miles, it is about -5,032,514,823,221,293.01, based on 1 Ly = 5,878,625,373,183.61 miles.

ER Boötis brightness ranges from a magnitude of 10.025 to a magnitude of 9.888 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.

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Additional ER Boötis Facts and Figures

Visual Facts

Primary / Proper / Traditional NameER Bootis
Alternative NamesHIP 72838, BD+36 2544, ER Boo
Spectral TypeM0
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeVariable Star
GalaxyMilky Way
Visual / Apparent Magnitude9.85
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)14h 53m 17.99
Declination (Dec.)+35° 53` 44.8
Galactic Latitude62.71966178 degrees
Galactic Longitude59.28013247 degrees
Distance from Earth-3.81000 Parallax (milliarcseconds)
 -856.07 Light Years
 -262.47 Parsecs
 -54,137,946.46 Astronomical Units
B-V Index1.52

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Mean Variability Period in Days0.087
Variable Magnitude Range (Brighter - Dimmer)9.888 - 10.025

Estimated Calculated Facts

Effective Temperature3,971 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

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