NASA's Picture of the Day takes on a celestial birdwatching theme as it showcases the captivating Seagull Nebula, offering astronomers a glimpse into its expansive beauty.
Birdwatching the Seagull Nebula
Resembling the outline of a bird in flight, this cosmic spectacle spans a vast 2.5-degree stretch across the Milky Way's plane, drawing observers into its intricate details.
According to NASA, the Seagull Nebula, also known by its catalog designations Sh2-296 and IC 2177, is situated near the direction of Sirius, the alpha star of Canis Major, the constellation of the Big Dog.
At its heart lies NGC 2327, a compact emission and reflection nebula housing a massive embedded star that forms the bird's distinctive head.
This region is believed to be part of a larger shell structure sculpted by successive supernova explosions, adding to the nebula's cosmic allure. The striking blue arc visible below and to the right of the center represents a bow shock generated by the runaway star FN Canis Majoris.
Composed primarily of hydrogen gas, the Seagull Nebula encompasses a diverse array of gas and dust clouds interspersed with stars from the Canis Majoris OB1 association, spanning over 200 light-years at an estimated distance of 3,800 light-years.
The capturing of Seagull Nebula's cosmic glory was made possible by astrophotographer Gianni Lacroce.
A Closer Look at the Cosmic Seagull
Constellation Guide provides further insights into the Seagull Nebula, situated approximately 3,650 light-years away in the constellation Monoceros, adjacent to Canis Major.
This expansive nebula comprises an H II region, open star clusters, dark dust clouds, and reflection nebulae, creating a mesmerizing interplay of light and shadow reminiscent of a seagull in flight.
The nebula's composition of interstellar dust, hydrogen, helium, and ionized gases reflects the dynamic interplay between stellar birth and death within its cosmic confines.
Energetic young stars within the nebula illuminate its surroundings, causing hydrogen gas to glow with a distinct reddish hue in long-exposure images.
Moreover, the light from hot blue OB-type stars is reflected off dust particles within the nebula, giving rise to patches of reflection nebulosity that contrast with the dominant red emission nebula.
The Seagull Nebula serves as a bustling stellar nursery, harboring dozens of massive OB stars, reflection nebulae, and embedded young star clusters within its sprawling expanse.
At the heart of the Seagull Nebula lies HD 53367, a triple star system featuring a young variable Herbig Ae/Be star surrounded by a compact cloud designated NGC 2327. This luminous star system emits strong ultraviolet radiation, illuminating the surrounding nebula and adding to its ethereal glow, according to Constellation Guide.
The compact cloud at the Seagull's head is individually recognized in the New General Catalogue as NGC 2327. Within the second Sharpless catalogue of HII regions (1959), the nebula is identified as Sh2-292.
Australian astronomer Colin Gum first recorded it in his catalog of emission nebulae found in the southern sky and labeled it as Gum 1. The Seagull's head is both an emission and reflection nebula. It mainly emits light due to the gas ionization produced by recently formed stars. Moreover, it reflects light from stars located beyond the nebula.