mick laBriola

This image features IC 3476, a dwarf galaxy that lies about 54 million light-years from Earth in the constellation Coma Berenices. Whilst this image does not look very dramatic — if we were to anthropomorphise the galaxy, we might say it looks almost serene — the actual physical events taking place in IC 3476 are highly energetic. In fact, the little galaxy is undergoing a process known as ram pressure stripping, which is driving unusually high levels of star formation within regions of the galaxy itself.  We tend to associate the letters ‘ram’ with the acronym RAM, which refers to Random Access Memory in computing. However, ram pressure has a totally distinct definition in physics: it is the pressure exerted on a body when it moves through some form of fluid, due to the overall resistance of the fluid. In the case of entire galaxies experiencing ram pressure, the galaxies are the ‘bodies’ and the intergalactic or intracluster medium (the dust and gas that permeates the space between galaxies, and for the latter the spaces between galaxies in clusters) is the ‘fluid’.  Ram pressure stripping occurs when the ram pressure results in gas being stripped from the galaxy. This stripping away of gas can lead to a reduction in the level of star formation, or even its complete cessation, as gas is absolutely key to the formation of stars. However, the ram pressure can also cause other parts of the galaxy to be compressed, which can actually boost star formation. This is what seems to be taking place in IC 3476: there seems to be absolutely no star formation going on at the edge of the galaxy bearing the brunt of the ram pressure stripping, but then star formation rates within deeper regions of the galaxy seem to be markedly above the average.

Arthur Hoag chanced upon this unusual extragalactic object. On the outside is a ring dominated by bright blue stars, while near the center lies a ball of much redder stars that are likely much older. Between the two is a gap that appears almost completely dark. How Hoag’s Object formed, including its nearly perfectly round ring of stars and gas, remains unknown. Genesis hypotheses include a galaxy collision billions of years ago and the gravitational effect of a central bar that has since vanished. The featured photo was taken by the Hubble Space Telescope and reprocessed using an artificially intelligent de-noising algorithm. Observations in radio waves indicate that Hoag’s Object has not accreted a smaller galaxy in the past billion years. Hoag’s Object spans about 100,000 light years and lies about 600 million light years away toward the constellation of the Snake (Serpens). Many galaxies far in the distance are visible toward the right, while coincidentally, visible in the gap at about seven o’clock, is another but more distant ring galaxy.

Heading for its next perihelion passage on April 21, Comet 12P/Pons-Brooks is growing brighter. The greenish coma of this periodic Halley-type comet has become relatively easy to observe in small telescopes. But thebluish ion tail now streaming from the active comet’s coma and buffeted by the solar wind, is faint and difficult to follow. Still, in this image stacked exposures made on the night of February 11 reveal the fainter tail’s detailed structures. The frame spans over two degrees across a background of faint stars and background galaxies toward the northern constellation Lacerta. Of course Comet 12P’s April 21 perihelion passage will be only two weeks after the April 8 total solar eclipse, putting the comet in planet Earth’s sky along with a totally eclipsed Sun.

Jeremy Webster “Fred” Frith (born 17 February 1949) is an English multi-instrumentalist, composer, and improviser.

Probably best known for his guitar work, Frith first came to attention as one of the founding members of the English avant-rock group Henry Cow. He was also a member of the groups Art Bears, Massacre, and Skeleton Crew. He has collaborated with a number of prominent musicians, including Robert Wyatt, Derek Bailey, the Residents, Lol Coxhill, John Zorn, Brian Eno, Mike Patton, Lars Hollmer, Bill Laswell, Iva Bittová, Jad Fair, Kramer, the ARTE Quartett, and Bob Ostertag. He has also composed several long works, including Traffic Continues (1996, performed 1998 by Frith and Ensemble Modern) and Freedom in Fragments (1993, performed 1999 by Rova Saxophone Quartet). Frith produces most of his own music, and has also produced many albums by other musicians, including Curlew, the Muffins, Etron Fou Leloublan, and Orthotonics.

He is the subject of Nicolas Humbert and Werner Penzel’s 1990 documentary Step Across the Border. Frith also appears in the Canadian documentary Act of God, which is about the metaphysical effects of being struck by lightning. He has contributed to a number of music publications, including New Musical Expressand Trouser Press, and has conducted improvising workshops across the world. His career spans over four decades and he appears on over 400 albums, and he still performs actively throughout the world.