Category Astronomy/Space

Location of the southern Antarctic Circumpolar Current front (white contour), with -1 degree Celsius sea surface temperature lines (black contours) on Sept. 22 each year from 2002-2009, plotted against a chart of the depth of the Southern Ocean around Antarctica. The white cross is Bouvet Island. Credit: NASA/JPL-Caltech

Why has the sea ice cover surrounding Antarctica been increasing slightly, in sharp contrast to the drastic loss of sea ice occurring in the Arctic Ocean? A new NASA-led study finds the geology of Antarctica and the Southern Ocean are responsible.

A NASA/NOAA/university team led by Son Nghiem of NASA’s Jet Propulsion Laboratory, Pasadena, California, used satellite radar, sea surface temperature, land form and bathymetry (ocean depth) data to study the physical processes a...

Hubble sees a swarm of ancient star clusters around lenticular galaxy NGC 5308, located just under 100 million light-years away in the constellation of Ursa Major

This NASA/ESA Hubble Space Telescope image shows star clusters encircling a galaxy, like bees buzzing around a hive: lenticular galaxy NGC 5308, just under 100 million light-years away in the constellation of Ursa Major (The Great Bear). Members of a galaxy type that lies between an elliptical and a spiral galaxy, lenticular galaxies such as NGC 5308 are disk galaxies that have used up, or lost, the majority of their gas and dust. As a result, they experience very little ongoing star formation and consist mainly of old and aging stars.

On Oct...

NASA’s artist impression of SN 2006gy, one of the most luminous hypernovae seen. Credit: NASA/CXC/M.Weiss

An international team has spotted a surprising UV rebrightening in a distant superluminous supernova, ASASSN-15lh. The event has baffled the scientists as has no hydrogen emission characteristic of superluminous supernovae and tidal disruption events. Also called hypernovae, these are dozens of times more luminous than normal supernovae. ASASSN-15lh, detected by the All Sky Automated Survey for SuperNovae (ASAS-SN) in 2015, is a real ‘assassin’ among these explosion events. It is about 200X more powerful than the average supernova and approximately 570 billion times brighter than our sun. It is so far the most luminous supernova ever detected.

Now, Brown et al have used data from NASA’...

Globular cluster M4. Credit: NOAO/AURA/NSF

Using recent advancements in Australian telescope tech, a Monash Uni team has made an unexpected discovery that a large group of stars are dying prematurely, challenging our accepted view of stellar evolution revealing that large numbers of helium burning stars are dying prematurely in the M4 globular cluster. M4 is one of the closest and brightest globular clusters, and has already been very well studied. “Globular clusters are some of the oldest objects in the Universe. Although we have some ideas for what is going on in them, every time we look carefully we find something unexpected” said Professor Lattanzio.

Researchers used a new instrument called a high efficiency and resolution multi-element spectrograph (HERMES)...