Lupus
“The Wolf” · Southern · best around June evenings
Real star positions and magnitudes (HYG database via D3-Celestial, BSD-3). Lines are the conventional stick figure; north is up.
The story
The wolf impaled on the Centaur's spear — an ancient constellation in the rich Milky Way between Scorpius and Centaurus. In 1006 the brightest supernova in recorded history — visible in daylight for weeks — blazed here.
How to find it
Between Antares and Alpha Centauri.
✦ What lives inside it
- SN 1006 site — history's brightest supernova
The deep dive
Researched for the Atlas from Wikipedia — Lupus (constellation) (5,377 characters read) · updated Sep 20, 2026
01 From Beast to Wolf: a long identity crisis
Lupus has one of the most tangled naming histories in the sky. For centuries it was not a constellation at all — ancient Greek and Roman stargazers treated it as a nameless animal dangling from the hand of Centaurus, killed or about to be killed on the centaur's behalf. Even Eratosthenes saw it not as a creature but as a wineskin held by Centaurus. It took Hipparchus of Bithynia, working in the 2nd century BC, to give the group its own standing, calling it Therion — Greek for "beast" — a deliberately vague label. Medieval Latin astronomers translated this as Fera, equally noncommittal. Only when Ptolemy's work reached Europe in Latin translation did a specific animal finally appear: the wolf. So the constellation spent most of ancient history as an unidentified animal, graduated to a generic beast, and arrived at "wolf" almost by translator's convention rather than by any mythological tradition.
02 The Babylonian Mad Dog lurking behind the stars Deeper
Long before Greek astronomy shaped the constellation we inherit, Babylonian sky-watchers mapped this region as the Mad Dog — written in cuneiform as UR.IDIM, or Uridimmu in Akkadian. The creature was a hybrid: a man's head and torso combined with the legs and tail of a lion. The cuneiform sign UR itself was broad enough to cover any large carnivore — lion, wolf, or dog — which hints at why the figure's identity kept slipping across cultures. In Babylonian sky lore the Mad Dog appears in company with the sun god and a Bison-man, a mythical being that scholars link to the Greek figure of Centaurus. That pairing is striking: just as the Babylonian Mad Dog stands beside the Bison-man, the Greek Therion (Lupus) stands beside Centaurus, suggesting the Greek constellation inherited not just the stars but the whole dramatic relationship between the two figures. Alpha Lupi received the formal proper name Uridim from the International Astronomical Union on 12 September 2024, directly honoring this Babylonian heritage.
03 How Arab and Islamic astronomers saw the Wolf
Arab folk astronomy did not separate Lupus from its neighbor at all. Lupus and Centaurus together carried a single poetic name: al-Shamareekh, meaning "the dense branches of the date palm's fruit" — a vivid agricultural image far removed from any predator. Islamic medieval astronomy took a different approach, naming the figure al-Sab', a general term for any predatory wild beast, directly echoing the Greek therion. Crucially, al-Sab' was treated as a distinct constellation but was still drawn together with Centaurus on charts and globes — the old visual bond refused to break entirely. The interpretation of what kind of beast it was also shifted depending on the manuscript. In some copies of Al-Sufi's celebrated Book of Fixed Stars, the figure is drawn as a lion; in others it appears as a wolf. Both forms fit al-Sab', illustrating how a deliberately ambiguous name allowed different illustrators to fill in the animal as they saw fit across centuries of copying.
04 A small but surprisingly star-rich constellation
Lupus covers 333.7 square degrees of sky — just 0.809 percent of the entire celestial sphere — placing it 46th in size among the 88 modern constellations. Despite its modest footprint, the constellation contains 127 stars within its borders that are brighter than or equal to apparent magnitude 6.5, the rough limit of naked-eye visibility under excellent conditions. Its official boundaries form a twelve-sided polygon, and the whole constellation sits between declinations of −29.83° and −55.58°, making it fully visible only to observers south of latitude 34° North. It is hemmed in by six neighboring constellations: Scorpius, Centaurus, Libra, Norma, Circinus, and Hydra — though Hydra only grazes a corner. The International Astronomical Union standardized its three-letter abbreviation as Lup in 1922, and its right ascension span runs from roughly 14 hours 18 minutes to 16 hours 9 minutes.
05 Alpha Lupi: a pulsating giant with a new ancient name Deeper
The brightest star in Lupus, Alpha Lupi, is classified as a blue giant of spectral type B1.5 III, lying 460 ± 10 light-years from Earth. It belongs to the Beta Cephei class of variable stars, meaning its surface physically pulses in and out, causing its brightness to vary by 0.03 of a magnitude on a precise cycle of 7 hours and 6 minutes. That variation is subtle — far too small to notice with the naked eye — but measurable with careful photometry. The star is also a massive member of the Scorpius–Centaurus OB association, the nearest large grouping of hot, young, massive stars to our solar system; most of Lupus's brightest stars belong to this same association. The star's new official proper name, Uridim, adopted by the IAU on 12 September 2024, ties it directly to the Babylonian constellation UR.IDIM. Earlier, R. H. Allen had assigned it the Chinese name Yang Mun in his book Star Names and Their Meanings, but that attribution is now considered an error.
06 The Retina Nebula: seeing a cylinder edge-on
On Lupus's western border sits IC 4406, a planetary nebula with a striking nickname — the Retina Nebula — earned by the grid-like pattern of dark dust lanes crossing its center when photographed in detail. The nebula is cylindrical in shape, and because we happen to view it almost perfectly side-on, it appears as an elongated oval rather than the circular ring we would see if looking straight down the cylinder's axis. It lies approximately 5,000 light-years away and is classed as a Wolf–Rayet planetary nebula, meaning the hot central star driving its glowing shell belongs to the intensely hot Wolf–Rayet category — among the hottest stars known to exist. The dust lanes threading IC 4406's interior are a relatively rare feature in planetary nebulae and give astronomers a window into how material organizes itself as a dying star expels its outer layers. The nebula sits on the western border of Lupus alongside two spiral galaxies, forming an unusually rich pocket of deep-sky interest at the constellation's edge.
07 SN 1006: the brightest stellar explosion in recorded history
Lupus holds the site of SN 1006, a supernova that various sources record as appearing on April 30 to May 1 of the year 1006. Historical accounts from across the medieval world — from Arab astronomers to Chinese court records to European monks — describe a brilliant new star blazing in the sky for months. It is widely regarded as the brightest stellar explosion observed in recorded human history, far outshining Venus at its peak and reportedly visible in daylight. The event occurred within the borders of what we now call Lupus, and its remnant — an expanding shell of superheated gas — is still studied by radio and X-ray astronomers today. The fact that this extraordinary event unfolded in a constellation that ancient astronomers struggled to even name independently is a quiet irony: a patch of sky considered secondary, a mere appendage to Centaurus, hosted perhaps the most dramatic single astronomical event any medieval observer ever witnessed.
08 Naming the stars: Lacaille, Gould, and 29 Bayer letters Deeper
The systematic labeling of Lupus's stars was a drawn-out process spread across more than a century. The French astronomer Lacaille initiated the work in 1756, assigning Bayer-style Greek letters — Alpha through Psi — to 29 stars, and supplementing them with Latin letters a through h. He was notably inconsistent: he labeled three separate stars all as a, and assigned duplicate designations for Kappa, Nu, Xi, Tau, Phi, and Psi. Johann Bode later added the Latin letter d to the roster. Then in 1879, the American astronomer Benjamin Gould judged that three additional stars deserved formal designations — Omega, i, and k — on the grounds that they were bright enough to warrant recognition. The tangle around the letter a was eventually resolved by dropping two of the three stars that shared it, leaving only a1 as an active designation. The result is a labeling system with visible seams, reflecting the practical messiness of cataloguing a southern constellation that northern European astronomers could observe only partially and intermittently.
09 ESO 274-1: a galaxy hiding in plain sight Deeper
Tucked into Lupus is ESO 274-1, a spiral galaxy viewed exactly edge-on from Earth, presenting itself as a thin sliver of stars and dust rather than the face-on spiral arms astronomers might prefer to see. Its dimensions are 9 arcminutes by just 0.7 arcminutes — a long, narrow needle shape — with a small, elliptical nucleus at its center. Viewing it demands serious equipment: an amateur telescope with at least 12 inches of aperture is required, and even then, the galaxy is only accessible under genuinely dark skies, away from city light pollution. Observers can star-hop to it by using Lambda Lupi and Mu Lupi as guide markers. The galaxy's edge-on orientation, while frustrating for studying its spiral structure, is scientifically valuable in other ways — it allows astronomers to measure the thickness of its disk and detect dust lanes in profile, details that face-on orientations tend to hide.
10 Globular clusters, open clusters, and a dark nebula
Lupus offers a varied deep-sky landscape across its modest area. Toward the constellation's northern reaches lie two globular clusters, NGC 5824 and NGC 5986, ancient balls of hundreds of thousands of stars gravitationally bound together. Close to them runs the dark nebula B 228, a cold cloud of gas and dust dense enough to blot out background stars rather than glow — visible only as an absence. Shifting south, two open clusters appear: NGC 5822 and NGC 5749, younger and looser groupings of stars born from the same molecular cloud. On the eastern border with Norma sits a third globular cluster, NGC 5927. Toward the center of the constellation, the planetary nebula NGC 5882 adds another class of object to the mix. The constellation also contains the transiting exoplanet Lupus-TR-3b, detected by its periodic dimming of its host star as it crosses in front — a discovery method that requires precise, sustained photometric monitoring across many observing sessions.