The AsterNym star registry
Alcor
Alcor: the white star of Ursa Major
white · Ursa Major · 80 UMa
Alcor is a white star, burning hotter than our own Sun in the constellation Ursa Major, one of the stars with a proper name recognised in the IAU Catalog of Star Names. At magnitude 3.99 it is visible to the naked eye under a dark sky.
Most stars in the sky are anonymous points of light. Alcor is not. Some IAU-recognised names are ancient; others were adopted by the IAU only recently. Either way, the star already has a scientific identity, and a dedication attaches a human story to it.
Real star · Personal dedication · Recorded in the AsterNym registry
See what a dedicated page looks like: preview
Alcor at a glance
- Constellation
- Ursa Major
- Other name
- 80 UMa
- Catalogue number
- HIP 65477
- Distance
- ≈ 82 light-years
- Brightness
- Magnitude 3.99 naked-eye
- Star type
- A5V SB
- Colour
- white
- Best seen from
- The Northern Hemisphere and lower southern latitudes
- Right ascension
- 13h 25m 14s
- Declination
- +54° 59′ 17″
J2000 catalogue coordinates that can be independently cross-checked against astronomical databases. A planetarium app showing coordinates of date will differ slightly, because proper motion and precession move a star’s apparent position over time.
What kind of star is Alcor?
Alcor is a white main-sequence star. Its surface runs around 7,500 to 10,000°C, hot enough to look white or blue-white to the eye. Colour in a star is a temperature reading rather than a decoration: the hot ones are blue and the cool ones red, the opposite way round to a kitchen tap.
These are the classic bright white stars. Sirius and Vega are both this kind, and they are the reason people describe stars as white when most of the galaxy's stars are actually red and too faint to see.
A star of this class gets roughly a thousand million years, a tenth of what the Sun gets.
It is a main-sequence star, which despite the word dwarf simply means it is in the long stable middle of its life, fusing hydrogen in its core exactly as the Sun is doing now.
Alcor drifts about 12.2 arcseconds a century against the stars behind it. Slow by any human measure, and still enough that the sky your distant descendants see will not be the one in your photographs.
The light you are looking at is old
The light you can see from Alcor left in 1944, which puts it roughly a lifetime ago. Nobody has invented anything since then that the light knows about; it has simply been travelling.
That delay is the part people find hardest and like most. A star is the one thing you can give someone that was already old before either of you was born and will outlast anything else you could have chosen.
It is comfortably visible without equipment on a decent night.
What could a Alcor dedication represent?
Alcor is especially meaningful for someone who:
- · Deserves something older than any gift shop
- · Marks a beginning, an anniversary or a promise
- · Is remembered every time you look up
- · Has a light you want recorded somewhere permanent
Dedication idea
“For the one I think of when I find Ursa Major in the sky.”
Where can you see Alcor?
It is easy to see from most of the Northern Hemisphere. It can also appear from lower southern latitudes, but it never rises for observers south of about latitude 35°S. It passes directly overhead at latitude 55°N. It stands highest at midnight in April, so April and May evenings are the best time to look. At magnitude 3.99 it is a naked-eye star only under a dark sky, binoculars make it certain.
Alcor belongs to Ursa Major.
What does Alcor mean in astrology?
The classical fixed-star tradition: Ptolemy, the medieval Behenian lists, Robson’s 1923 compilation. Is silent on Alcor, and we don’t invent lore where none exists. What astrology can still read is the star’s real position, below.
Projected onto the zodiac the way fixed-star astrology reads any star, Alcor stands at 15° Virgo at the J2000 epoch, and the Sun passes that degree around 4 September in the years around 2000. Fixed-star longitude shifts slowly against the tropical zodiac because of precession, about one degree every seventy-two years, so a natal conjunction must be calculated for the birth year rather than read off this J2000 value or a calendar date.
Traditional interpretations, not facts or predictions. The position and dates are computed.
Dedicate Alcor to someone who matters
A flower fades. A card is eventually put away. A star gives your message a place in the sky.
from$29.95a year
Dedicate Alcor →Real star · your message · a page to share
Your Alcor dedication includes
- Your chosen dedication name
- Your personal message
- Alcor's real astronomical coordinates
- A shareable dedication page
- Its location on the AsterNym Galaxy Map
- An optional printable certificate and gift presentation
Alcor keeps its established astronomical name. Your dedication is a personal commemorative record within the AsterNym registry.
Frequently asked questions about Alcor
- What does Alcor mean in astrology?
- The classical fixed-star tradition has no documented meaning for Alcor. Projected onto the zodiac, Alcor stands at 15° Virgo, and the Sun passes that degree each year around 4 September.
- Is Alcor the brightest star?
- Alcor shines at magnitude 3.99 · visible to the naked eye on a clear night, one of the few thousand stars with an officially recognised name.
- How far away is Alcor?
- Alcor is approximately 82 light-years from Earth. The light reaching us tonight began its journey around 82 years ago.
- Which constellation contains Alcor?
- Alcor is part of Ursa Major.
- Can everyone see Alcor?
- It is easy to see from most of the Northern Hemisphere. It can also appear from lower southern latitudes, but it never rises for observers south of about latitude 35°S. It passes directly overhead at latitude 55°N. It stands highest at midnight in April, so April and May evenings are the best time to look. At magnitude 3.99 it is a naked-eye star only under a dark sky, binoculars make it certain.
- Is dedicating Alcor an official astronomical renaming?
- No. Alcor keeps its internationally recognised astronomical name. An AsterNym dedication records your personal name and message in the AsterNym registry without changing the star's scientific identity.
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