VulpeculaVUL-90 — Fox-Field Planetary-Nebula Array

Vulpecula is a faint northern constellation in the heart of the summer Milky Way. Johannes Hevelius introduced it in the seventeenth century as Vulpecula cum Ansere, the Little Fox with the Goose, though the goose eventually disappeared from the official constellation name. Vulpecula’s stars are unimpressive, but its deep-sky content is not. Messier 27, the Dumbbell Nebula, is one of the brightest and easiest planetary nebulae for amateur telescopes. The field also contains Brocchi’s Cluster, commonly called the Coathanger, a striking chance alignment of stars best seen in binoculars. Vulpecula therefore ends the 88-constellation archive on an appropriate note: a constellation most people cannot recognize by its stars, hiding one of the best telescope objects in the northern sky.

Field Overview

Vulpecula covers about 268 square degrees, ranking 55th among the 88 constellations. It lies between Cygnus, Sagitta, Delphinus, Pegasus and Hercules.

Anser, Alpha Vulpeculae, is the brightest star at only about magnitude 4.4. The remaining principal stars are even fainter.

The summer Milky Way runs directly through the field, creating a dense stellar background. That richness makes the constellation difficult to trace naked-eye but excellent for binocular sweeping.

How to Find Vulpecula

Find the Summer Triangle—Vega, Deneb and Altair. Vulpecula lies inside the broad triangle, south of Cygnus and north of Sagitta.

Anser is the best internal anchor, but the Coathanger asterism and M27 are often more memorable practical landmarks.

June through October evenings are best, especially July through September. Vulpecula is well placed from northern mid-latitudes and visible from much of the Southern Hemisphere.

Notable Stars

Anser, Alpha Vulpeculae, is an orange giant around magnitude 4.4 and lies roughly 290 light-years away. Its proper name preserves part of Hevelius’s original Fox-and-Goose imagery: Anser means goose.

23 Vulpeculae, around magnitude 4.5, is another useful naked-eye reference.

HD 189733 is a K-type star around magnitude 7.7 and hosts one of the best-studied hot-Jupiter exoplanets. HD 189733 b became famous because its atmosphere has been observed in extraordinary detail, including evidence of high-altitude hazes and extreme weather.

PSR B1919+21 lies in Vulpecula and was the first pulsar ever discovered, in 1967 by Jocelyn Bell Burnell and Antony Hewish’s research team. The repeating radio signal was so unexpected that it was briefly nicknamed “LGM-1” before its neutron-star nature became clear.

Deep-Sky Objects

Messier 27, the Dumbbell Nebula, is Vulpecula’s premier object. It is a planetary nebula created when a Sun-like star expelled its outer layers late in its life. Under dark skies it is visible in binoculars as a small oval haze and is excellent in small telescopes.

M27’s broad hourglass or dumbbell shape becomes increasingly obvious with aperture and nebula filters. It is one of the easiest planetary nebulae for beginners because it is large, bright and forgiving.

Brocchi’s Cluster, Collinder 399, is the Coathanger asterism. It looks like a straight bar of stars with a hook and is best viewed in binoculars. Most of its stars are not a true physical cluster; the pattern is largely a chance alignment.

NGC 6823 and surrounding nebula NGC 6820 provide additional cluster and emission-nebula targets for wide-field imaging.

History, Naming & Origin

Hevelius introduced the constellation as Vulpecula cum Ansere, the Little Fox with the Goose, in the late seventeenth century. The fox was depicted carrying a goose.

The name was gradually shortened to Vulpecula, Little Fox, while Alpha Vulpeculae retained the proper name Anser as a linguistic fossil of the lost goose.

That makes Vulpecula’s nomenclature unusually self-documenting: the deleted half of the constellation survives in the name of its brightest star.

Observing Notes

Vulpecula is best with binoculars. Scan the Milky Way between Cygnus and Sagitta rather than trying to force a naked-eye fox.

M27 is an excellent first planetary nebula and handles moderate magnification well. An O III filter can improve contrast significantly.

The Coathanger is best at very low power; many telescopes magnify too much to show the entire shape comfortably.

RELATED CONSTELLATIONS: - Cygnus — Deneb and the Northern Cross dominate the northern boundary. - Sagitta — small Arrow lies immediately south. - Delphinus — compact eastern neighbor. - Aquila — Altair provides broad southern orientation. - Hercules — western/northwestern region. - Pegasus — eastern autumn boundary region.

CARS-05 FIELD NOTES

VUL-90 is a high-background concealment field. The target constellation is weak while unrelated asterisms and deep-sky objects are far more memorable.

Operators repeatedly solve the Coathanger or navigate directly to M27 and declare success.

Those are excellent destinations. Neither is the Fox.

— OPD Technologies, Celestial Navigation Division

Related Fields

• Cygnus — Deneb and the Northern Cross dominate the northern boundary.
• Sagitta — small Arrow lies immediately south.
• Delphinus — compact eastern neighbor.
• Aquila — Altair provides broad southern orientation.
• Hercules — western/northwestern region.
• Pegasus — eastern autumn boundary region.

CARS-05 Field Notes