star formation tagged posts

Star formation in the outer spiral regions of the galaxy NGC 4625 is seen in ultraviolet light (blue); these arms are nearly invisible in optical light, but have hot, newborn stars that radiate in the UV. A new study finds that the star formation processes in these outer regions generally resemble the processes at work in more normal, denser regions where molecular gas abounds. The atomic gas is traced in the radio (purple); optical starlight is red. Credit: NASA/JPL-Caltech/Carnegie Observatories/WSRT

Star formation environments can be roughly grouped into 3 types, categorized by the density of their gas (or more precisely, the projected “surface” density of the gas, which is easier to determine than volume density)...

Visualising the local solar neighbourhood in 3D. Credit: ESA. Acknowledgement: H. Bouy (CSIC-INTA) & J. Alves (U. Vienna

Astronomers have used modern techniques to visualise data from ESA’s Hipparcos space astrometry mission in 3D. This offered insights into the distribution of nearby stars and uncovered new groupings of stars in the solar neighbourhood, shedding light on the origins of the stars in Orion and calling into question the existence of the Gould Belt – an iconic ring-shaped structure of stars in the Milky Way. The results show the potential of 3D visualisation of the solar neighbourhood, an approach which is of particular relevance to ESA’s Gaia mission which will map the Milky Way and Local Group in 3D with unprecedented sensitivity and accuracy.

3D map of massive O and B ty...

An image of Camargo 791, one of the newly found embedded clusters. Credit: Camargo et al.

When a giant cloud of molecular gas condenses, star clusters are born. It may sound simple but the formation of star clusters is a very complex process. By peering into this process we could get valuable information on the evolution of galaxies and improve our knowledge about large cosmic structures in the universe. “Star clusters are often considered as building blocks of galaxies. Understanding how these objects form and evolve is vital to our comprehension of the structure, formation and evolution of galaxies,” Denilso Camargo.

Camargo and his colleagues recently discovered a multitude of star clusters using NASA’s Wide-field Infrared Survey Explorer: 652 star clusters, stellar groups and candidate...

This is the “South Pillar” region of the star-forming region called the Carina Nebula. Like cracking open a watermelon and finding its seeds, the infrared telescope “busted open” this murky cloud to reveal star embryos tucked inside finger-like pillars of thick dust. Credit: NASA

A type of gas found in the voids between galaxies – atomic gas – appears to be part of the star formation process under certain conditions. The findings overturn a long-standing theory about the conditions needed for star formation to take place – a process that happens when dense clouds of dust and gas inside galaxies collapse.

It was previously thought that stars could form only in the presence of a different type of gas – called molecular gas. Atomic gas is composed of individual H atoms...