Birthday Stars
Astronomers measure distances to the stars in terms of light years, units that combine time and distance. One light year is the distance light travels in one year; so if you look at a star ten light years from Earth, the light you see from it left ten years ago and is therefore ten years old.
To see starlight that's your age—or the age of a friend or family member—use the table below. When you've found the star whose light is the right age, you can:
- Copy its name and paste it into our star chart to find its location in the sky. If it's a bright star, you might try to find it by printing the star chart, making a red-light, night-vision flashlight, and heading outside. If it's dim, you may need a telescope. Try going to a star party or public observatory and ask the astronomers to show it to you. (Visit our Local Societies page to find local amateur astronomers.)
- Find out more about it by going to STARS—a web site by an astronomer devoted to the bright stars.
The table below lists:
- The age of the person whose star you're looking for.
- The star's name. Stars can have several names, ranging from Arabic or Greek proper names for the brightest stars (such as Sirius) to various catalog numbers. The names used in this column work best for locating the star using the "find" command on digital star charts. Stars used to be named in order of brightness within a given constellation in order of their brightness, with Alpha being the brightest, Beta the second-brightest, and so on. (In this system, the constellation name is given with the Latin genitive case; so the brightest star in Orion is Alpha Orionis or Alpha Ori.) Early estimates of which star is brightest were based on visual observations alone and often proved to be flawed, but the naming system is still widely employed.
- The star's precise distance, in light years.
- The star's apparent magnitude ("Mag."), a measure of its brightness as seen from Earth. (In this system, the numbers get larger as the stars get dimmer. Bright stars are of magnitude 0, 1, or 2, while the dimmest stars generally visible with unaided eyes are of about magnitude 6.) Stars in this table with magnitudes dimmer than about 6 can only be viewed with binoculars or a telescope. Exceptionally bright stars have negative magnitudes (such as Sirius, the brightest star in our skies, mag. -1.4.) A star's apparent magnitude—how bright it looks to us—results from both its actual light output and its distance from Earth—so an inherently brilliant star that is far from Earth will look dim in the sky, while an ordinary star nearby will look bright (which is the case for the Sun!).
- Comments. Here we give a bit more information on each star (including the name of the constellation, or star pattern, in which it is located, and its location, referenced in compass directions (N, S, E, W) and degrees ("deg.") on the sky. To estimate degrees of angle in the sky ("deg." in our comments table), consider that your fist at arm's length takes up about 10 degrees of the sky, while the full Moon is about half a degree wide.
Most of the stars in this table can be seen from Earth's northern hemisphere with the naked eye. Exceptions, listed in italics, are those either too dim to see without binoculars or a telescope (check their magnitudes and note it is higher than 6) or too far south to be seen from most locations in the northern hemisphere.
Birthday Star Chart
Note: Stars listed in italics are too dim to see by naked eye.
Your Age | Star | Distance (light years) | Magnitude | Comments |
---|---|---|---|---|
0 | Sun | (8 light-minutes) | -26.7 | The "birthday star" for babies born today is the Sun! |
4 | Alpha Centauri | 4.4 | 0 | Nearest known star to the Sun; actually part of a triple star system; bright, but too far south to be seen from North America |
6 | Barnard's Star | 6 | 5.9 | E. E. Barnard discovered that this star is speeding toward the Sun; it will become the nearest star to us in 10,000 years |
8 | Wolf 359 | 7.8 | 13.4 | Very faint dwarf in Leo, the Lion; visible with a medium-sized telescope |
9 | Sirius | 8.6 | -1.4 | Brightest star in Earth's skies; can cast shadows on dark, clear nights |
10 | Epsilon Eri | 10.5 | 3.7 | Less luminous than the Sun today but may resemble the young Sun (closest star known to have a planet) |
11 | Procyon | 11.4 | 0.4 | More luminous than the Sun and about twice as big; in Canis Minor, near Sirius |
12 | Tau Ceti | 11.9 | 3.5 | First star to be examined by radio astronomers searching for signals from intelligent life; they heard nothing |
15 | Gliese 876 | 15.3 | 10.2 | Dwarf star in Aquarius, the Water Bearer; has planets |
16 | Keid | 16.5 | 4.4 | Multiple star (as discovered by William Herschel) in Eridanus, the River, W of Orion |
17 | Altair | 16.8 | 0.8 | Bright, rapidly-spinning star in Aquila, the Eagle |
18 | Van Biesbroeck's Star | 18.7 | 17.4 | Small, dim, cool star that sometimes flares up |
19 | Eta Cass | 19.4 | 3.5 | Westernmost star in the "W" of Cassiopeia, the Queen; Sunlike, has an orange companion—as Herschel discovered, in August 1779 |
20 | 36 Oph | 19.5 | 4.3 | Double star which can be resolved ("split") with a small telescope; 10 deg. SW of the bright star Antares |
21 | Xi Bootes | 21.9 | 4.5 | Double star, resolvable with small telescopes |
24 | 107 Piscium | 24.4 | 5.2 | Inconspicuous orange dwarf in Pisces, the Fishes |
25 | Vega | 25.3 | 0 | Brilliant blue-white "diamond" star in Lyra, the Lyre; may be forming planets |
26 | Chi Draconis | 26.3 | 3.6 | Lies E of the bowl of the Little Dipper |
27 | Beta CVn | 27.3 | 4.2 | Yellow star NW of the Big Dipper's bowl, in the constellation Canes Venatici, the Hunting Dogs |
28 | Chi1 Ori | 28.3 | 4.4 | In Orion, The Hunter, 12 deg. N of Betelgeuse |
29 | Gamma Lep | 29.3 | 3.6 | Double star, "splittable" with binoculars and of attractive colors, sometimes described as yellow and garnet; in Lepus, the Hare |
30 | Kappa1 Cet | 29.9 | 4.8 | Multiple star in Cetus, the Whale, SW of Aldebaran |
31 | 61 UMa | 31.1 | 5.3 | In Ursa Major, the Big Bear, 20 deg. S of Big Dipper's bowl; may have planets |
32 | 12 Oph | 31.9 | 5.8 | Variable star but otherwise resembles the Sun; in Ophiuchus, the Serpent Handler, |
33 | Alpha Men | 33.1 | 5.1 | Southern-hemisphere star in Mensa, the Table |
34 | Pollux | 33.7 | 1.2 | The southern (and warmer-colored) member of the two bright stars, Castor and Pollux, in Gemini, the Twins |
35 | Zeta Her | 35.2 | 2.8 | Multiple star at the SW corner of the "Keystone" of Hercules, the legendary strongman |
36 | Denebola | 36.2 | 2.1 | "The Lion's Tail"; resembles Sirius |
37 | Arcturus | 36.7 | -0.1 | "Follow the arc"—of the Big Dipper's handle—"to Arcturus" is the start of many star-finding lessons; in Bootes, the Herdsman |
38 | Lambda Ser | 38.3 | 4.4 | Yellow star in Serpens, the Serpent |
39 | Delta Cap | 38.6 | 2.8 | White star on the ecliptic in Capricorn, the Goat |
40 | Beta Tra | 40.2 | 2.8 | Southern star, 9 deg. E of Alpha Centauri in Triangulum Australe, the Southern Triangle |
41 | Lambda Aur | 41.2 | 4.7 | Elderly dwarf star due S of Capella in Auriga, the Charioteer |
42 | Capella | 42.2 | 0.1 | Brightest star in Auriga; color variously described as reddish to golden, perhaps because it is a double star but too close to be resolved even through a telescope |
43 | 58 Eri | 43.4 | 5.5 | Sunlike star in Eriadanus, the River |
44 | Theta UMa | 43.9 | 3.2 | Yellow star SE of the Big Dipper's bowl |
45 | Gamma Cep | 44.9 | 3.2 | Located 12deg from Polaris, in Cepheus, the Ethiopian King |
46 | Alpha For | 46.3 | 3.9 | Double star in Fornax, the Furnace |
47 | Eta Cep | 46.7 | 3.4 | In Cepheus, 20deg. SW of the "W" in Cassiopeia; one of Barnard's dark nebulae lies 1.6deg. S |
48 | Alderamin | 48.8 | 2.5 | Bright star in Cepheus, the King; the slow wobble of Earth's axis (called "precession") will make it the north Pole Star—5,500 years from now |
49 | 51 Peg | 50 | 5.5 | Just E of the "Great Square" of Pegasus, the Winged Horse; first normal star around which planets were discovered |
50 | Delta Aql | 50.1 | 3.4 | In the Milky Way at the center of Aquila, the Eagle |
51 | Castor | 51.6 | 1.6 | Northern (and bluer) of Gemini's two brightest stars |
52 | 104 Tau | 51.8 | 4.9 | In Taurus, the Bull, 7.5 deg. W of Aldebaran; twice as old as the Sun |
53 | Xi Peg | 53 | 4.2 | In Pegasus, SW of the Great Square |
54 | Beta Cas | 54.5 | 2.3 | Easternmost star in the "W" of Cassiopea; variable |
55 | Tau1 Hya | 55.8 | 4.6 | SW of Leo, in Hydra, the Water Snake |
56 | Xi Oph | 56.7 | 4.4 | In the Milky Way in Ophiuchus, near the ecliptic |
57 | 58 Oph | 57.2 | 4.9 | On the ecliptic E of Scorpius |
58 | Delta Leo | 57.7 | 2.6 | Luminosity 50 times the Sun's; 10 deg. NW of Denabola |
59 | 70 Vir | 59.1 | 5 | Sunlike star in Virgo, the Virgin |
60 | Navi | 60.9 | 4.8 | Yellow star E of Gamma Cas, the center of Cassiopeia's "W" |
61 | Mu Vir | 60.9 | 3.9 | In Virgo, W of Libra |
62 | Eta Ser | 61.8 | 3.2 | In Serpens, the Serpent, 8 deg. NW of the "Wild Duck" star cluster (M11) |
63 | Beta Pic | 62.9 | 3.9 | In the southern constellation Pictor, the Painter, 6 deg. NW of the bright star Canopus; appears to be forming planets |
64 | Alpha Tri | 64.1 | 3.4 | In Triangulum, the Northern Triangle, 4 deg. SW of the Pinwheel galaxy (M33) |
65 | Aldeberan | 65.1 | 0.9 | Brightest star in Taurus, the Bull |
66 | Alpha Ari | 65.9 | 2 | Giant star W of the Pleiades |
67 | Sigma2 U Ma | 66.7 | 4.8 | In Ursa Major, W of the Big Dipper's bowl, |
68 | Tau Cyg | 68.3 | 3.7 | Outlying star in Cygnus, the Swan, just under 10 deg. SE of Deneb |
69 | 40 Leo | 69 | 4.8 | In central Leo, less than 1 deg S of the bright star Algieba |
70 | Zeta Lep | 70.2 | 3.55 | Blue-white star S of Orion in Lepus, the Hare |
71 | Alpha Hya | 71.3 | 2.9 | Orange giant, wide as 30 Suns; brightest star in Hydra, the Water Snake |
72 | Epsilon Cyg | 72.1 | 2.5 | Tepid orange giant; innermost star in the right wing of Cygnus, the Swan |
73 | Mu Cyg | 73.06 | 4.5 | Close double star whose duplicity was discovered by William Herschel; at tip of the Swan's right wing |
74 | 39 Leo | 74.1 | 5.8 | On the Lion's back, 0.3deg. SE of the brighter star Adhafera; use binoculars |
75 | Alphecca | 74.7 | 2.2 | Eclipsing binary star that changes brightness (by only 0.1 magnitude) every 17.4 days; in Corona Borealis, the Northern Crown |
76 | Omega Dra | 76.5 | 4.8 | Near Little Dipper, in Draco, the Dragon |
77 | Regulus | 77.5 | 1.4 | Blue-white giant, 120 times as luminous as the Sun; brightest star in Leo |
78 | Mizar | 78.2 | 2.2 | Naked-eye double star with its partner, the fainter Alcor, and itself a telescopic double; in Ursa Major, at the crook of the Big Dipper's handle |
79 | SAO1002 | 78.6 | 10.4 | Double star in Camelopardalis, the Giraffe; requires a telescope |
80 | 7 And | 79.9 | 4.5 | One star among many in the rich star clouds of the Milky Way, in Andromeda |
81 | Alioth | 80.9 | 1.8 | The "bright eye" in the Big Dipper's handle, immediately W of Mizar and Alcor |
82 | Beta Oph | 81.9 | 2.8 | Pale yellow; good in binoculars |
83 | Zeta Aql | 83.3 | 3 | Tip of Aquila the Eagle's West wing |
84 | Sabik | 84.1 | 2.4 | White star E of Scorpius, in the ecliptic near the Milky Way |
85 | Seginus | 85.2 | 3 | Just under 10 deg. N of Arcturus |
86 | Tau3 Eri | 86.2 | 4.1 | SW of Orion, in Eridanus, the River |
87 | Algorab | 87.9 | 2.9 | At the NE corner of Corvus, the Crow |
88 | Epsilon Cet | 88.2 | 4.8 | In Cetus, the Whale, 10 deg. SE of Mira |
89 | Ascella | 89.1 | 2.6 | Bright enough to stand out against the rich star clouds of the central Milky Way; in eastern Sagittarius, the Archer. |
90 | 15 Peg | 90.2 | 5.5 | In Pegasus, on the E edge of the Milky Way's glowing river of stars |
91 | 38 Gem | 91.1 | 4.7 | In Gemini, all but lost amid Milky Way star clouds |
92 | Omega And | 92.3 | 4.8 | Look 9 deg. NE of the Andromeda galaxy |
93 | Algol | 92.8 | 2.1 | The most famous variable star in the sky; an "eclipsing binary" that dips in brightness, from mag. 2.1 to mag. 3.4, when the primary star is partly eclipsed by its dimmer companion. In Perseus, 18 deg. NNE of the Pleiades star cluster. |
94 | Lambda Gem | 94.3 | 3.6 | Variable star of the Cepheid type, which can be used to measure distances; in Gemini, at the right knee of the eastern Twin |
95 | Gamma Oph | 94.8 | 3.75 | In Ophiuchus, 18 deg. NW of the Wild Duck star cluster (M11) |
96 | Diphda | 95.8 | 2 | A yellow star near the ecliptic in Cetus, the whale |
97 | Alpheratz | 97.1 | 2.1 | NE corner of the "Great Square" linking Andromeda and Pegasus; spectrum displays "weather" in form of sulfur clouds on its surface |
98 | SAO141665 | 98 | 4.5 | In central Ophiuchus |
99 | Nu1 Dra | 99.9 | 4.9 | Part of a telescopic double star in Draco, the Dragon |
100 | Nu2 Dra | 99.9 | 4.9 | The other member of this pretty pair of white stars (see 99) |
101 | Alkaid | 100.7 | 1.85 | White star at the tip of the Big Dipper's handle |
Some Comments on the Chart
Looking over the chart, you may have noticed that it's missing entries for several ages—notably 2, 3, 5, and 7—and that our entry for age 6, Barnard's Star, is too dim to be seen without a telescope. But at greater distances there's a bright star for nearly every age. What's up with that? The reason is that as we go out farther, we're sampling steeply larger volumes of space, and therefore have more stars to choose from. (The volume goes up as 4/3?R3, where ? = 3.14 and R is the distance, meaning the radius of the sphere in which we are searching.) In cases where we had several options, we have picked the brightest star visible from northern latitudes, where most—though by no means all!—observers dwell.
Certain commercial concerns offer to "name" stars for individuals—at a price. These star "registries" have no official sanction. Astronomical objects are named by the International Astronomical Union, according to internationally agreed-upon protocols which do not permit naming stars for living persons. Stars rarely get names these days, but catalog numbers But while you cannot legitimately name a star for yourself or a friend or family member, we invite you to observe a star whose light is as old as you are, or they are, and to possess a photo of it if you like. Like the night sky, it's free!
Our list of Birthday Stars is based on a book project of that title initiated by Timothy Ferris in 1997. For another approach, visit the Joint Astronomy Center in Hawaii.