Corona Borealis is a small constellation in the Northern Celestial Hemisphere. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Its brightest stars form a semicircular arc. Its Latin name, inspired by its shape, means "northern crown". In classical mythology Corona Borealis generally represented the crown given by the god Dionysus to the Cretan princess Ariadne and set by her in the heavens. Other cultures likened the pattern to a circle of elders, an eagle's nest, a bear's den, or even a smokehole. Ptolemy also listed a southern counterpart, Corona Australis, with a similar pattern.
Telescopium is a minor constellation in the southern celestial hemisphere, one of twelve named in the 18th century by French astronomer Nicolas-Louis de Lacaille and one of several depicting scientific instruments. Its name is a Latinized form of the Greek word for telescope. Telescopium was later much reduced in size by Francis Baily and Benjamin Gould.
R Leporis (R Lep), sometimes called Hind's Crimson Star, is a well-known variable star in the constellation Lepus, near its border with Eridanus. It is designated "R" in the chart to the right.
R Coronae Borealis is a low-mass yellow supergiant star in the constellation of Corona Borealis. It is the prototype of the R Cor Bor class of variable stars, which fade by several magnitudes at irregular intervals. R Coronae Borealis itself normally shines at approximately magnitude 6, just about visible to the naked eye, but at intervals of several months to many years fades to as faint as 15th magnitude. Over successive months it then gradually returns to its normal brightness, giving it the nickname "reverse nova", after the more common type of star which rapidly increases in brightness before fading.
T Coronae Borealis, is a recurring nova in the constellation Corona Borealis. It was first discovered in outburst in 1866 by John Birmingham, although it had been observed earlier as a 10th magnitude star.
S Coronae Borealis is a Mira variable star in the constellation Corona Borealis. Its apparent magnitude varies between 5.8 and 14.1, with a period of 360 days—just under a year. Within the constellation, it lies to the west of Theta Coronae Borealis, and around 1 degree southeast of the eclipsing binary star U Coronae Borealis.
RR Coronae Borealis is a M3-type semiregular variable star located in the constellation Corona Borealis with a parallax of 2.93mas being a distance of 341 parsecs (1,110 ly). It varies between magnitudes 7.3 and 8.2 over 60.8 days. Located around 1228 light-years distant, it shines with a luminosity approximately 2180 times that of the Sun and has a surface temperature of 3309 K.
Gamma Coronae Borealis, Latinized from γ Coronae Borealis, is a binary star system in the northern constellation of Corona Borealis. It is visible to the naked eye with an apparent visual magnitude of 3.83. Based upon an annual parallax shift of 22.33 mas as seen from Earth, it is located about 146 light years from the Sun. The system is moving closer to the Sun with a radial velocity of about −15 km/s.
Mu Coronae Borealis, Latinized from μ Coronae Borealis, is a solitary, ruby-hued star located in the northern constellation of Corona Borealis. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.12. Based upon an annual parallax shift of 5.27 mas, it is located roughly 620 light years from the Sun. This is an evolved red giant star with a stellar classification of M1.5 IIIb. It is currently on the asymptotic giant branch and is a variable star of uncertain type, showing a change in brightness with an amplitude of 0.0147 magnitude and a frequency of 0.02455 cycles per day, or 40.7 days/cycle. On average, it is radiating 932 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,889 K.
RY Sagittarii is a yellow supergiant and an R Coronae Borealis type variable star in the constellation Sagittarius. Although it ostensibly has the spectrum of a G-type star, it differs markedly from most in that it has almost no hydrogen and much carbon.
RS Telescopii, abbreviated RS Tel, is a variable star in the southern constellation of Telescopium. It is a dim star with an apparent visual magnitude of 10.67, which is much too faint to be visible without a telescope. The variability of this star was discovered by Evelyn F. Leland and announced by Edward C. Pickering in 1910. It was first studied by Cecilia H. Payne in 1928 at the Harvard College Observatory.
VY Pyxidis is a BL Herculis variable in the constellation of Pyxis. It ranges between apparent magnitudes 7.13 and 7.40 over a period of 1.23995 days. Located around 650 light-years distant, it shines with a luminosity approximately 45 times that of the Sun and has a surface temperature of 5892 K.
R Leonis Minoris is a Mira variable type star in the constellation Leo Minor. It ranges between apparent magnitude 6.3 and 13.2, and spectral types M6.5e to M9.0e (Tc:), over a period of 372 days.
W Coronae Borealis is a Mira-type long period variable star in the constellation Corona Borealis. Its apparent magnitude varies between 7.8 and 14.3 over a period of 238 days.
U Coronae Borealis is an Algol-type eclipsing binary star system in the constellation Corona Borealis. Its apparent magnitude varies between 7.66 and 8.79 over a period of 3.45 days. The component stars are a blue-white main sequence star of spectral type B6V and a cooler yellow-white subgiant star of spectral type F8III-IV.
Upsilon Coronae Borealis, Latinized from υ Coronae Borealis, is a solitary star in the northern constellation of Corona Borealis. It is a white-hued star that is dimly visible to the naked eye with an apparent visual magnitude of 5.78. The distance to this object is approximately 630 light-years based on parallax.
R Normae is a Mira variable star located near Eta Normae in the southern constellation of Norma. This is an intermediate-mass red giant star that is generating part of its energy through hydrogen fusion. Because this fusion is thought to be occurring under conditions of convection, it is generating an excess of lithium. The star ranges from magnitude 6.5 to 12.8 and has a relatively long period of 496 days. Located around 2,900 light-years distant, it shines with a luminosity 7764 times that of the Sun and has a surface temperature of 3161 K.
RS Coronae Borealis is a semiregular variable star located in the constellation Corona Borealis with a parallax of 2.93mas being a distance of 341 parsecs (1,110 ly). It varies between magnitudes 8.7 to 11.6 over 332 days. It is unusual in that it is a red star with a high proper motion. Located around 1072 light-years distant, it shines with a luminosity approximately 1839 times that of the Sun and has a surface temperature of 3340 K.
R Capricorni (R Cap) is a star in the constellation of Capricornus. It has an apparent visual magnitude which varies between 9.4 and 14.9. A mira variable and ageing red giant, it is in the asymptotic giant branch stage of its lifespan.
V Crucis is a carbon star in the constellation Crux. A Mira variable, its apparent magnitude ranges from 8.7 to 11.1 over 376.5 days.
