HR Double Stars


The Harvard Revised Photometry Catalogue, compiled and first published in 1908 by the Harvard College Observatory, was the first edition of what later became known as the Bright Star Catalogue.  It includes a wealth of information about all stars in both the northern and southern hemispheres of the sky down to the putative naked-eye limit of visual magnitude 6.5, sometimes a bit fainter.  These stars are numbered HR 1 through HR 9110 in order of right ascension for equinox 1900.  Almost all go-to telescopes include the entire Bright Star Catalogue in their firmware, so this provides a handy way to quickly point to the brighter double stars, since the menagerie of double star catalogues (Σ, OΣ, OΣΣ, β, AC, ADS, Es, h, Ho, S, WDS) and even Bayer and Flamsteed designations are poorly supported, if at all.

What follows below is a list of "interesting" visual double and multiple star systems where at least one component is bright enough to garner it a Bright Star Catalogue number.  The vast majority of these stars come from my own observing notebook, based on my observations over the past 20 years.    As such, there are gaps.  Since most of those 20 years I lived in Iowa and—for five years—Wisconsin, coverage may be a bit spotty in the winter constellations because of the bone-chilling cold prevalent during those months.  Similarly, some excellent double stars south of declination -30° may have been missed because at latitude 42° - 43° N,  they are 12° - 13° lower in the southern sky than they are here in the Big Bend.  These are gaps, however, that I am eager to fill, so if you have a favorite double star that is not listed below, please email me and I will make it a point to observe your double and probably add it to this list.

The double and multiple stars below are organized by constellation, not in alphabetical order, but in order of the right ascension of the leading (western) edge of each constellation.  For example, the second constellation listed, Eridanus, covers a range of right ascension from 1h22m (the leading western edge) to 5h09m (the following eastern edge).  Now, this is a handy thing to know, because the best time to observe an object is when it is highest in the sky.  That occurs when the right ascension of the object is close to the local sidereal time, which is just the right ascension of objects currently crossing your celestial meridian.  There are a number of apps and web sites that will calculate your local sidereal time, and almost all planetarium software will display for you the local sidereal time as well.  For example, you can go to Heavens Above to get the local sidereal time at Alpine at this very moment.

In simpler terms, the constellations are listed below in the order that they rise above the eastern horizon.  Ursa Minor, listed first, is always above the horizon as it is circumpolar here in its entirety.


Ursa Minor, 0:00 to 24:00
HR 424 (Polaris, α UMi)

Eridanus, 1:22 to 5:09
HR 1211 / 1212 (32 Eri)
HR 1325 (Keid, ο2 Eri)

Perseus, 1:26 to 4:46
HR 834 (η Per)

Triangulum, 1:29 to 2:48
HR 642 (ι Tri)

Aries, 1:44 to 3:27
HR 545 / 546

Fornax, 1:44 to 3:48
HR 749 (ω For)

Camelopardalis, 3:11 to 14:25
HR 1622 / 1623 (11 & 12 Cam)

Taurus, 3:20 to 5:58
HR 1065
HR 1174 (30 Tau)
HR 1411 / 1412 (θ Tau)

Auriga, 4:35 to 7:27
HR 1707 (R Aur)
HR 1779

Orion, 4:41 to 6:23
HR 1713 (Rigel, β Ori)
HR 1899 (ι Ori; triple!)
HR 1931 (σ Ori; quadruple!)

Lepus, 4:54 to 6:09
HR 1771 (triple!)
HR 1982 / 1983 (γ Lep)

Monoceros, 5:54 to 8:08
HR 2298 / 2299 (ε Mon)
HR 2356 / 2357 / 2358 (β Mon; triple!)

Gemini, 5:57 to 8:06
HR 2890 / 2891 (Castor, α Gem; triple!)

Puppis, 6:02 to 8:26
HR 2909 / 2910
HR 2948 / 2949 (κ Pup)
HR 3026 / 3027
HR 3079

Canis Major, 6:09 to 7:26
HR 2593 (μ CMa)
HR 2618 (ε CMa)
HR 2764

Lynx, 6:13 to 9:40
HR 2783 / 2784 (19 Lyn)

Cancer, 7:53 to 9:19
HR 3208 / 3209 (ζ Cnc; triple!)
HR 3474 / 3475 (ι Cnc)

Ursa Major, 8:05 to 14:27
HR 4374 / 4375 (ξ UMa)
HR 4486
HR 5054 / 5055 /5062 (Mizar & Alcor, 79 & 80 UMa; triple!)

Hydra, 8:08 to 14:58
HR 3482 (ε Hya)
HR 3759 (τ1 Hya)
HR 4443 / 4444

Pyxis, 8:26 to 9:26
HR 3425

Leo, 9:18 to 11:56
HR 3982 (Regulus, α Leo)
HR 4057 / 4058 (Algieba, γ Leo)

Leo Minor, 9:19 to 11:04
HR 3764 (7 LMi)

Draco, 9:18 to 21:00
HR 6184 / 6185 / 6186 (16 & 17 Dra; triple!)
HR 6369 / 6370 (Alrakis, μ Dra)
HR 6554 / 6555 (Kuma, ν Dra)
HR 6636 / 6637 (ψ1 Dra)
HR 7582 (ε Dra)

Sextans, 9:39 to 10:49
HR 4193 (35 Sex)

Crater, 10:48 to 11:54
HR 4405 (gamma Crt)
HR 4428

Centaurus, 11:03 to 14:59
HR 5210 / 5211 (3 Cen)

Virgo, 11:35 to 15:08
HR 4677 / 4678
HR 4825 / 4826 (Porrima, γ Vir)
HR 4963 (θ Vir)

Corvus, 11:54 to 12:54
HR 4757 (Algorab, δ Crv)
HR 4821 / 4822

Coma Berenices, 11:57 to 13:33
HR 4698
HR 4791 / 4792 (24 Com)
HR 4884 (32 & 33 Com)

Canes Venatici, 12:04 to 14:05
HR 4666 (2 CVn)
HR 4914 / 4915 (Cor Caroli, α CVn)

Boötes, 13:33 to 15:47
HR 5328 / 5329 (κ Boo)
HR 5386
HR 5414 / 5415
HR 5475 / 5476 (π Boo)
HR 5505 / 5506 (Izar, ε Boo)
HR 5544 (ξ Boo)
HR 5733 / 5734 (μ Boo; triple!)
HR 5763 (ν Boo)

Lupus, 14:13 to 16:05
HR 5925 / 5926 (ξ Lup)
HR 5948 (η Lup)

Libra, 14:18 to 15:59
HR 5530 / 5531 (Zubenelgenubi, α Lib)

Serpens (Caput, Cauda), 14:55 to 18:56
HR 5788 / 5789 (δ Ser)
HR 6446 (ν Ser)
HR 7141 / 7142 (θ Ser)

Corona Borealis, 15:14 to 16:22
HR 5833 / 5834 (ζ CrB)
HR 6063 / 6064 (σ CrB)

Scorpius, 15:44 to 17:55
HR 5984 / 5985 (Graffias, β Sco)
HR 6026 / 6027 (ν Sco; quadruple!)
HR 6084 (Alniyat, σ Sco)

Hercules, 15:47 to 18:56
HR 6406 / 6407 (Ras Algethi, α Her)
HR 6410 (δ Her)
HR 6484 / 6485 (ρ Her)
HR 6592
HR 6729 / 6730 (95 Her)
HR 6781 / 6782 (100 Her)

Ophiuchus, 15:58 to 18:42
HR 6112 / 6113 (ρ Oph)
HR 6401 / 6402 (36 Oph)
HR 6424 / 6425 (ο Oph)
HR 6752 (70 Oph)

Sagittarius, 17:41 to 20:25
HR 6693 / 6694

Lyra, 18:12 to 19:26
HR 7051 / 7052 / 7053 / 7054 (ε Lyr; quadruple!)
HR 7140

Scutum, 18:18 to 18:56
HR 6946

Aquila, 18:38 to 20:36
HR 7059 (5 Aql)
HR 7300
HR 7307
HR 7593 / 7594 (57 Aql)

Sagitta, 18:56 to 20:18
HR 7463 (ε Sge)
HR 7475
HR 7705 (θ Sge)

Vulpecula, 18:56 to 21:28
HR 8101

Cygnus, 19:07 to 22:01
HR 7293 / 7294
HR 7417 / 7418 (Albireo, β Cyg)
HR 7503 / 7504 (16 Cyg)
HR 7730 / 7735 (30 & 31 Cyg; triple!)
HR 7942 (52 Cyg)
HR 8085 / 8086 (61 Cyg)

Cepheus, 20:01 to 8:30
HR 8238 (Alfirk, β Cep)
HR 8281 (triple!)
HR 8357
HR 8417 (Kurhah, ξ Cep)
HR 8571 (δ Cep)
HR 881

Capricornus, 20:04 to 21:57
HR 7747 / 7754 (Algedi, α Cap)
HR 7776 (Dabih, β Cap)
HR 7829 / 7830 (ο Cap)

Delphinus, 20:13 to 21:06
HR 7947 / 7948 (γ Del)

Microscopium, 20:25 to 21:25
HR 7965 (α Mic)

Aquarius, 20:36 to 23:54
HR 8396 (29 Aqr)
HR 8480 (41 Aqr)
HR 8558 / HR 8559 (ζ Aqr; middle star  of the Water Jar)
HR 8866 (94 Aqr)

Equuleus, 20:54 to 21:23
HR 8034 (ε Equ)

Pegasus, 21:06 to 0:13
HR 8173 (1 Peg)
HR 8364
HR 8798

Piscis Austrinus, 21:25 to 23:04
HR 8576 (β PsA)

Grus, 21:25 to 23:25
HR 8521 / 8524 (π Gru; quadruple!)

Lacerta, 21:55 to 22:56
HR 8603 (8 Lac)

Pisces, 22:49 to 2:04
HR 50 (35 Psc)
HR 167 (55 Psc)
HR 230 / 231 (65 Psc)
HR 310 / 311 (ψ1 Psc)
HR 595 / 596 (Alrisha; α Psc)

Andromeda, 22:56 to 2:36
HR 379
HR 603 / 604 (Almach, γ And)
HR 628 / 629 (59 And)

Cassiopeia, 22:56 to 3:36
HR 9094
HR 219 (η Cas)
HR 707 (ι Cas; triple!)

Sculptor, 23:04 to 1:44
HR 9044

Cetus, 23:55 to 3:21
HR 531 (χ Cet)
HR 650 (66 Cet)
HR 681 (Mira, ο Cet)
HR 804 (γ Cet)
HR 910 / 911 (Menkar, α Cet)