Star profile
Rho Cassiopeiae
Variable starWhat is Rho Cassiopeiae
Rho Cassiopeiae is one of the most extraordinary stars in the sky: a yellow hypergiant whose distance is measured in thousands of light-years and whose luminosity is hundreds of thousands of times that of the Sun. From time to time it undergoes singular eruptions in which its atmosphere cools abruptly and ejects masses equivalent to whole planets. It is a direct candidate to explode as a supernova on astronomically short timescales —that is, anywhere between tomorrow and a few tens of thousands of years.
Where it is and when to see it
Rho Cassiopeiae lies in the northern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is October, when it culminates around midnight.
- From London it never sets and culminates about 84° up.
- From New York it never sets and culminates about 73° up.
- From Sydney it never rises above the horizon.
It can be seen from anywhere north of 33° S.
It ranks no. 14 in brightness among the 93 stars of Cassiopeia in our catalogue. To find it, start from Cih, the brightest: it lies about 9° away (a fist at arm's length covers about 10°).
The light you see today left it about 330,000 years ago.
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A public signature from a real person. The chosen name is a symbolic denomination within Stelvia, with no official standing or IAU recognition: the sky is not for sale and belongs to no one.
Astronomical data for Rho Cassiopeiae
- Constellation
- Cassiopeia
- Apparent magnitude
- 4.51
- Distance
- 326200.0 light years
- Coordinates (J2000)
- RA 358.596° · Dec 57.499°
- Catalogue
- HIP 117863 · HD 224014
A symbolic commemorative gift: neither the signature nor the chosen name implies ownership of the star or recognition by the IAU.
Other stars in Cassiopeia
Cassiopeia has 93 stars in Stelvia's catalogue. Here are a few of them.
- CihGamma Cassiopeiae2.15
- SchedarAlpha Cassiopeiae2.24
- CaphBeta Cassiopeiae2.28
- Iota Cassiopeiae4.46
- Omicron Cassiopeiae4.48
- 48 Cassiopeiae4.49
- CastulaUpsilon 2 Cassiopeiae4.62
- Chi Cassiopeiae4.68