The “interstellar space” that spreads between stars is not an empty vacuum, but contains interstellar gas and interstellar dust. These gases and dust, collectively known as the interstellar medium, are not evenly distributed, and denser regions than the surroundings are called “dark nebulae.”
As the name suggests, dark nebulae themselves cannot be seen with visible light that humans can perceive. Observations using infrared rays and radio waves, which have longer wavelengths than visible light, have revealed that dark nebulae contain various molecules. Therefore, dark nebulae are also called “molecular clouds”.
[▲Darknebula”Lagia3″inthedirectionoftheconstellationofthesouthernskyandreflectionnebula”Burns149″illuminatedbytwobluestars”HR5999″and”HR6000″atitscenter(Credit:CTIO/NOIRLab/DOE/NSF/AURA/TARector(UniversityofAlaskaAnchorage/NSF’sNOIRLab)）]
This image shows the dark nebula “Lupus 3” about 500 light-years away in the direction of “Lupus” in the southern sky.
Two blue stars (HR 5999 and HR 6000) shine at the center of the constellation 3. The two stars brightly illuminate the gas and dust in blue, called Reflection Nebula Bernes 149, and together with 3 Lupus create a spectacular vista. A reflection nebula is, as the name suggests, a nebula that shines by reflecting the light of a star rather than emitting its own light.
The substances (molecules) contained in the constellation 3 of the lepus will be the materials that create new stars. HR 5999 and HR 6000 also originated and grew within Libra 3. The two stars are still one million years old, and are pre-main sequence stars of a type called “Taurus T-type stars,” which are the pre-stage of main-sequence stars like the Sun. Despite their brightness, the two stars still do not glow from nuclear fusion energy like the sun does, but from contracting and heating under their own gravity.
During the formation process of a T Tauri star, a powerful stellar wind is ejected that blows away gas and dust. The Burns 149 was created from that residue. Thus, 3 Lupus is an active star-forming region, and provides knowledge on star formation such as protostars.
This image is from the Dark Energy Camera (DECam) wide-field camera installed on the Victor M. Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory, NOIRLab. Taken at
Lupus 3 is one of at least nine dark nebulae that make up a complex of molecular clouds, and it is said that it spreads over a range equivalent to the apparent diameter of 24 full moons. By combining DECam’s wide field of view with the light-gathering ability of the Blanco 4-meter telescope, a sharp, high-resolution image of the constellation 3 was obtained.
Finally, here’s a zoomed-in video of Lupus 3 and Barnes 149.
Source
- Image Credit: CTIO/NOIRLab/DOE/NSF/AURA/ T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab); Processing: D. de Martin & M. Zamani (NSF’s NOIRLab)
- Video Credit: NOIRLabAstro
- NOIRLab – Radiant Protostars and Shadowy Clouds Clash in Stellar Nursery
Sentence/Tetsuro Yoshida
