The AsterNym star registry
Arcturus
Arcturus: the guardian whose light opened a World's Fair
warm orange · Boötes · α Boo · fourth-brightest star in the night sky
Arcturus is the golden-orange giant that dominates northern spring evenings, the Bear Guardian, following the Great Bear around the pole as it has in stories for thousands of years.
In 1933, its light, collected by telescopes, was used to switch on the lights of the Chicago World's Fair. A star that watches over things, and occasionally turns the lights on: that is a protector's dedication.
Real star · Personal dedication · Recorded in the AsterNym registry
See what a dedicated page looks like: preview
Arcturus at a glance
- Constellation
- Boötes
- Other name
- α Boo
- Catalogue number
- HIP 69673
- Distance
- ≈ 37 light-years
- Brightness
- Magnitude -0.05 naked-eye
- Rank
- fourth-brightest star in the night sky
- Star type
- K1.5 III
- Colour
- warm orange
- Best seen from
- Almost everywhere on Earth
- Right ascension
- 14h 15m 40s
- Declination
- +19° 10′ 57″
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 Arcturus?
Arcturus is an orange giant. Its surface runs roughly 4,000 to 5,000°C, cool enough that the light carries a visible orange. 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.
Its colour is not the whole story. An orange star still in the steady part of its life would burn for tens of thousands of millions of years. This one is past that stage, and it is cool at the surface because it has swollen outward, not because it was born this way.
It is a giant, which is what a star becomes when it exhausts the hydrogen in its core. It has swollen outward and cooled at the surface, and it is now brighter than it ever was as a young star. The Sun will do this too, in about five thousand million years.
Arcturus is one of the fastest-moving stars in the sky. It shifts about 228 arcseconds every century, which sounds tiny and is not: over a human lifetime it visibly changes position against the stars behind it. The constellations are not fixed, they are just slow, and this one is in a hurry.
The light you are looking at is old
The light you can see from Arcturus left in 1989, 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 also one of the brighter stars in the sky, which is why it carries a proper name at all rather than a catalogue number.
What does the name Arcturus mean?
Arcturus is Greek for “guardian of the bear”, arktouros, the herdsman who follows Ursa Major, the Great Bear, across the sky.
What could a Arcturus dedication represent?
Arcturus is especially meaningful for someone who:
- · Watches over the people they love
- · Is warm the way this star is golden
- · Turned the lights on in your life
- · Follows through, night after night
Dedication idea
“For my guardian, the warm light behind me all along.”
Where can you see Arcturus?
It sits 19° north of the celestial equator, so it clears the horizon everywhere short of latitude 71°S, in practice, every inhabited latitude on Earth. It passes directly overhead at latitude 19°N. It stands highest at midnight in April, so April and May evenings are the best time to look. At magnitude -0.05 it is bright enough to hold its own over city lights.
Arcturus belongs to Boötes, where it is the brightest star.
What does Arcturus mean in astrology?
The Bear-guard, brightest star of the northern sky. Behenian, nature of Mars and Jupiter: prosperity through one's own determination, the pathfinder who does well by going first.
Projected onto the zodiac the way fixed-star astrology reads any star, Arcturus stands at 24° Libra at the J2000 epoch, and the Sun passes that degree around 13 October 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 Arcturus 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 Arcturus →Real star · your message · a page to share
Your Arcturus dedication includes
- Your chosen dedication name
- Your personal message
- Arcturus's real astronomical coordinates
- A shareable dedication page
- Its location on the AsterNym Galaxy Map
- An optional printable certificate and gift presentation
Arcturus keeps its established astronomical name. Your dedication is a personal commemorative record within the AsterNym registry.
Frequently asked questions about Arcturus
- What does Arcturus mean in astrology?
- The Bear-guard, brightest star of the northern sky. Behenian, nature of Mars and Jupiter: prosperity through one's own determination, the pathfinder who does well by going first. Projected onto the zodiac, Arcturus stands at 24° Libra, and the Sun passes that degree each year around 13 October.
- Is Arcturus the brightest star?
- Arcturus is the fourth-brightest star in the night sky as seen from Earth. Sirius is the brightest.
- How far away is Arcturus?
- Arcturus is approximately 37 light-years from Earth. The light reaching us tonight began its journey around 37 years ago.
- Which constellation contains Arcturus?
- Arcturus is the brightest star in Boötes.
- Can everyone see Arcturus?
- It sits 19° north of the celestial equator, so it clears the horizon everywhere short of latitude 71°S, in practice, every inhabited latitude on Earth. It passes directly overhead at latitude 19°N. It stands highest at midnight in April, so April and May evenings are the best time to look. At magnitude -0.05 it is bright enough to hold its own over city lights.
- Is dedicating Arcturus an official astronomical renaming?
- No. Arcturus 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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