NGC 6740

NGC 6740 is an astronomical object in the constellation Aquila. It is commonly cataloged as a nebula-like source and is listed in the New General Catalogue (NGC), a historical compilation of deep-sky objects.

Classification and general description

NGC 6740 is found in the Milky Way and is associated with emission characteristics typical of nebular targets in optical catalogs. In observing practice, objects in this region are often discussed alongside nearby deep-sky sources in Aquila, where line-of-sight overlap can complicate interpretation.

Because the NGC is a broad catalog covering multiple types of deep-sky objects, sources like NGC 6740 are routinely cross-referenced with modern catalogs and surveys that refine positions, morphologies, and physical descriptions. Astronomers often compare older NGC entries with measurements from surveys such as the Sloan Digital Sky Survey to clarify what a given NGC number corresponds to in current terminology.

Catalog history

NGC 6740’s designation comes from the New General Catalogue, compiled in the 19th century to systematize observations of nebulae and clusters. Entries from this era were based on telescopic appearance, and subsequent work has refined many NGC descriptions using improved instrumentation and spectroscopy.

To interpret historical NGC identifications, researchers frequently consult cross-indexes in resources like the SIMBAD astronomical database. Such databases consolidate aliases, positional data, and literature references, helping distinguish between similar-looking objects that may share a region of the sky.

Observational targets in Aquila

Aquila hosts a rich set of emission and reflection nebulae and related star-forming structures, many of which are visible in amateur and professional surveys. When observing NGC-numbered targets in this area, astronomers commonly reference nearby constellational landmarks such as Aquila to orient the field and to compare surrounding features.

In this part of the sky, observers may also encounter objects cataloged in other systems—e.g., entries in Messier objects—though NGC 6740 itself is not part of the Messier catalog. Field comparisons remain useful for identifying how NGC 6740 appears relative to adjacent nebular emission and dust structures.

Data sources and modern study

Modern characterization of deep-sky objects typically relies on multi-wavelength data. Optical imaging and spectroscopy can trace ionized gas, while infrared observations can highlight dust-enshrouded regions where star formation occurs. Surveys that publish such data include 2MASS and other infrared programs that support studies of dusty environments in the Milky Way.

For researchers seeking precise coordinates and curated references for NGC 6740, database tools like SIMBAD astronomical database and other online catalogs provide aggregated information. These resources are often used to reconcile older catalog descriptions with contemporary analyses, including updates to object type, angular size, and associations with surrounding structures.

See also

• Aquila (constellation)
• New General Catalogue
• SIMBAD astronomical database
• Sloan Digital Sky Survey
• Two Micron All Sky Survey

Categories: Astronomical objects, Nebulae, Aquila (constellation)