[5] Classified as a dwarf irregular galaxy, the SMC has a D25 isophotal diameter of about 5.78 kiloparsecs (18,900 light-years),[1][3] and contains several hundred million stars.

[6] At a distance of about 200,000 light-years, the SMC is among the nearest intergalactic neighbors of the Milky Way and is one of the most distant objects visible to the naked eye.

The galaxy is located across the constellation of Tucana and part of Hydrus, appearing as a faint hazy patch resembling a detached piece of the Milky Way.

Persian astronomer Al Sufi mentions them in his Book of Fixed Stars, repeating a quote by the polymath Ibn Qutaybah, but had not observed them himself.

[9] Between 1834 and 1838, John Frederick William Herschel made observations of the southern skies with his 14-inch (36 cm) reflector from the Royal Observatory.

Between 1893 and 1906, under the direction of Solon Bailey, the 24-inch (610 mm) telescope at this site was used to survey photographically both the Large and Small Magellanic Clouds.

[11] Henrietta Swan Leavitt, an astronomer at the Harvard College Observatory, used the plates from Arequipa to study the variations in relative luminosity of stars in the SMC.

Leavitt realized that since all the stars in the SMC are roughly the same distance from Earth, this result implied that there is similar relationship between period and absolute brightness.

In 2017, using the Dark Energy Survey plus MagLiteS data, a stellar over-density associated with the Small Magellanic Cloud was discovered, which is probably the result of interactions between the SMC and LMC.

HMXB pulsars are rotating neutron stars in binary systems with Be-type (spectral type 09-B2, luminosity classes V–III) or supergiant stellar companions.

Recent studies using XMM-Newton[27] and Chandra[28] have now cataloged several hundred X-ray sources in the direction of the SMC, of which perhaps half are considered likely HMXBs, and the remainder a mix of foreground stars, and background AGN.

[30] An X-ray astronomy instrument was carried aboard a Thor missile launched from Johnston Atoll on September 24, 1970, at 12:54 UTC for altitudes above 300 km, to search for the Small Magellanic Cloud.