La Superba (Y Canum Venaticorum)
La Superba (Y Canum Venaticorum) is a star in the constellation Canes Venatici, magnitude 5.4.
One of the reddest stars in the sky — a cool carbon giant, nearly ready to shed its skin.
In the 19th century the Jesuit astronomer Angelo Secchi called this star’s spectrum ‘superba’. In 1876 the Irish astronomer John Birmingham turned the word into a name, and the IAU adopted La Superba officially in 2018. It is Italian for ‘the magnificent’.
It is one of the reddest stars known, and the reason is carbon. La Superba is a carbon star: deep churning has dredged carbon up from its interior into its atmosphere, where molecules soak up blue and violet light. At about 2,760 kelvins it is also one of the coolest stars known, and it is the brightest of the rare J-stars, rich in carbon-13.
Placed where the Sun is, its surface would reach beyond Earth’s orbit. Near the end of its life, it is shedding gas fast and is wrapped in a vast shell of material it has already thrown off. Soon, as stars count time, it should cast off its outer layers as a planetary nebula, leaving its core behind as a white dwarf.
La Superba (Y Canum Venaticorum) is 1,000 light-years away: the light we see from it set off around 1030, around the time Chinese astronomers recorded the supernova that made the Crab Nebula.
Did you know?
- A once-stronger wind. The vast shell of material around La Superba shows that it once lost mass as much as 50 times faster than it does today.
- Rhythms within rhythms. Its brightness wanders by about a magnitude over roughly 160 days, with slower swings on top. Periods of 194 and 186 days have also been suggested.
- Seen by IRAS. The IRAS infrared satellite found La Superba surrounded by one of the most prominent dust shells in its whole-sky survey.
A 5th-magnitude star of deep orange-red, about seven degrees north of Cor Caroli. Its colour is obvious in binoculars — compare it with white Cor Caroli — and it slowly changes brightness over a few months.
When and where to see it
It is best placed in the evening sky around May, when it crosses the meridian at about 10 pm local time (around midnight in April). It can be seen from everywhere north of 45°S and never sets north of 45°N.
At its highest it stands 85° up from 50°N, 80° up from 35°N, 45° up from the equator, 10° up from 35°S.
Facts
- Type
- Star
- Constellation
- Canes Venatici
- Designations
- Y Canum Venaticorum, Y CVn, HR 4846, HD 110914, HIP 62223
- Magnitude
- 5.4
- Position
- RA 12h 45.1m, Dec +45° 26′ (J2000)
- Spectral type
- C-N5
- Colour
- deep red (B−V 2.54)
- Brightness
- varies from magnitude 4.8 to 6.3
- Distance
- 1,000 light-years
- Discovered
- Named by John Birmingham in 1876, after Angelo Secchi’s description of its spectrum
Open AstroPilot to see when La Superba (Y Canum Venaticorum) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view.