C/1846 J1 (Brorsen)

Lore & Background

The comet was discovered on May 1, 1846, by Theodor Brorsen, who described it as a large round nebulosity without tail. An independent discovery was done later the same day by Moritz Ludwig George Wichmann. Upon discovery, the comet was near the border of the constellations Pegasus and Vulpecula. It approached Earth at a distance of 0.302 astronomical units on May 6.

The comet was observed with the naked eye on 13 May, after the Moon had set, and continued to be visible until 20 May, during which a faint tail was observed. Due to slow communications, George Phillips Bond discovered the comet on May 20 unaware of the previous discoveries. In June the comet became progressively harder to observe as the solar elongation became smaller. It was last observed on June 15, located low near the horizon.

The orbit of the comet has a striking similarity with the orbit of the weak December sigma Virginids (#428) meteor shower, which peaks on 20–22 December, but seems to be active from December 1 to January 10. The shower seems to be the same as the epsilon Virginids (#513). The peak zenithal hourly rate is about 1.5 for visual meteors.

Reader's Guide

C/1846 J1 (Brorsen) holds significance primarily as the parent body of the weak December sigma Virginids meteor shower, which peaks on 20–22 December and is active from December 1 to January 10. The shower is also identified with the epsilon Virginids (#513). Its legacy is tied to the orbital similarity that links the comet to this meteor stream, despite the shower's low activity—its peak zenithal hourly rate is only about 1.5 visual meteors. The comet's discovery history is notable for multiple independent discoveries: Theodor Brorsen first spotted it on 1 May 1846, followed later the same day by Moritz Ludwig George Wichmann, and then by George Phillips Bond on 20 May, who was unaware of the earlier finds due to slow communications. The comet's closest approach to Earth occurred on 6 May at 0.302 astronomical units, and it was visible to the naked eye from 13 to 20 May, displaying a faint tail. Its observation ended on 15 June as it became low near the horizon. The comet's long-period orbit and its connection to a weak meteor shower make it a subject of interest for studies of comet-meteor associations.

Did You Know?

• The comet was discovered independently three times: by Theodor Brorsen, Moritz Ludwig George Wichmann, and George Phillips Bond.
• It approached Earth to within 0.302 astronomical units (45,200,000 km) on 6 May 1846.
• The comet is the parent body of the December sigma Virginids meteor shower, which peaks on 20–22 December.
• The meteor shower has a peak zenithal hourly rate of only about 1.5 visual meteors.

From Poverty to the Stars

Edward Emerson Barnard entered the world in Nashville, Tennessee, in December 1857, into circumstances that shaped his entire trajectory. His father, Reuben Barnard, had passed away just three months before the boy's arrival, leaving the family in financial hardship. With little access to formal schooling, young Edward found his first calling in the darkroom, serving as a photographer's assistant by the age of nine. It was this hands-on, practical environment that eventually drew his gaze skyward. In 1876 he saved enough to buy a five-inch refractor telescope, and the results were remarkable: within a few years he had spotted multiple comets, though he never publicly claimed the very first one. By 1881 he had married Rhoda Calvert, a British-born woman, while still working at the photography studio. Word of his comet-finding ability spread among Nashville's amateur astronomy community, who pooled their resources to secure him a fellowship at Vanderbilt University. Though he never completed a degree there, the institution would later bestow upon him the sole honorary degree in its history. In 1887 he moved to Lick Observatory in California, where tensions with director Edward S. Holden over telescope time and research priorities would eventually push him elsewhere.

Seeing What Others Missed

Barnard's career was defined by moments of extraordinary observational acuity. In 1882 he recorded the gegenschein, a faint glow opposite the Sun in the sky, without knowing that Theodor Brorsen and T. W. Backhouse had published on the phenomenon earlier. Four years later, while tracking the moon Iapetus as it slid behind Saturn's rings, he noticed a shadow sweeping across the moon's surface. He did not immediately grasp the significance, but what he had witnessed was the first evidence of Saturn's mysterious spokes—dark radial features that would not be confirmed until Voyager 1 flew past the planet decades later. In 1892 he made two landmark observations: he was the first to identify gaseous emissions from a nova, correctly concluding it represented a stellar explosion, and he spotted Amalthea, Jupiter's fifth moon. That discovery was the first new Jovian satellite found since Galileo in 1609, and it remains the last one ever identified through direct visual observation rather than photographic plates. Then in 1916 he revealed that the faint star now called Barnard's Star possesses an unusually high proper motion, making it the second-closest stellar system to our Sun after Alpha Centauri.

The Comet Hunter of Nashville

Between 1881 and 1892, Barnard identified fifteen comets, three of which turned out to be periodic, and he co-discovered two more. His early success attracted the attention of Hulbert Harrington Warner, who was offering a bounty of two hundred dollars—roughly six thousand in today's value—for each new comet found. Barnard collected enough of these rewards to build a home for himself and his wife, Rhoda. Among his many finds, one stands out for its historical significance: D/1892 T1, known as Barnard 3, was the first comet ever discovered through photography rather than through a visual sighting. That same object was lost for over a century before being recovered in late 2008 under the designation 206P/Barnard–Boattini. His periodic comet 177P/Barnard, originally catalogued as P/1889 M1, was also rediscovered in 2006. The sheer volume of his comet work—spanning a dozen years and including objects like C/1886 T1, the Barnard–Hartwig comet, and C/1891 F1, the Barnard–Denning comet—cemented his reputation as one of the most prolific and skilled comet hunters of the nineteenth century, all achieved largely with modest instruments and an extraordinary eye.

A Legacy Written in Light and Shadow

Barnard's influence extends far beyond any single discovery. As a pioneering astrophotographer, he mapped the Milky Way with meticulous care, and together with Max Wolf he demonstrated that certain dark patches in the galaxy were clouds of gas and dust blocking the light of more distant stars. His systematic catalogue of these dark nebulae, running from Barnard 1 through Barnard 370, was first published in a 1919 paper in the Astrophysical Journal. From 1905 his niece Mary R. Calvert served as his assistant at the University of Chicago, where he held the professorship and used the forty-inch telescope at Yerkes Observatory. After his death in Williams Bay, Wisconsin, in February 1923, Mary and Edwin B. Frost completed his photographic work, publishing A Photographic Atlas of Selected Regions of the Milky Way in 1927. His honors include the Lalande Prize, the Royal Astronomical Society's Gold Medal, the Bruce Medal, and the Prix Jules Janssen. Objects bearing his name span the solar system and beyond: a lunar crater, a Martian crater, a region on Ganymede, asteroid 819 Barnardiana, NGC 6822, Barnard's Loop, and the star that carries his name.