Tag: Hubble

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Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope and is the third of a seven-day celebration of galaxies by the Hubble science team. Previous images in the series can be found here. From the caption for this particular image:

At the center of NGC 6951 lies a supermassive black hole surrounded by a ring of stars, gas, and dust about 3,700 light-years across. This “circumnuclear ring” is between 1 and 1.5 billion years old and has been forming stars for most of that time. Scientists hypothesize that interstellar gas flows through the dense, starry bar of the galaxy to the circumnuclear ring, which supplies new material for star formation. Up to 40 percent of the mass in the ring comes from relatively new stars that are less than 100 million years old. Spiral lanes of dust, shown in dark orange, connect the center of the galaxy to its outer regions, contributing more material for future star formation.

This galaxy, located about 78 million light years away, has also seen six different supernovae in the past quarter century. Compare that with the Milky Way, which has not seen a supernova now in more than four hundred years.

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Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope. It shows what scientists dub a lenticular galaxy, with features that put it somewhere between a spiral galaxy and an elliptical (which has no structure a appears instead a cloud of stars), sitting about 73 million light years away.

NGC 3156 has been studied in many ways … from its cohort of globular clusters, to its relatively recent star formation, to the stars that are being destroyed by the supermassive black hole at its centre.

Why this galaxy has no spiral arms is somehow related to its age and its central black hole, but the detailed theories that astronomers have to explain this are far from confirmed.

The image is interesting also because of its lack of foreground stars or background galaxies. Its location in the sky explains this, as Hubble was looking at right angle to the Milky Way’s galactic plane, essentially looking directly into the vast emptiness between the galaxies.

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Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of a follow-up observations of a supernova that occurred in this galaxy in 2015. The galaxy, dubbed IC 1776, is about 150 million light years away.

Hubble investigated the aftermath of the supernova SN 2015ap during two different observing programmes, both designed to comb through the debris left by supernovae explosions in order to better understand these energetic events. A variety of telescopes automatically follow up the detection of supernovae to obtain early measurements of these events’ brightnesses and spectra. Complementing these measurements with later observations which reveal the lingering energy of supernovae can shed light on the systems which gave rise to these cosmic cataclysms in the first place.

As the caption notes, the spiral arms of this galaxy “are difficult to distinguish.” At first glance the galaxy instead appears triangular in shape, an impression that dissolves with a closer look.

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A cool image to start the week! The picture to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope as part of a survey scientists are doing using Hubble, attempting to get high resolution images of every galaxy within about 30 million light years of the Milky Way. Prior to this census Hubble had covered about 75% of these galaxies. This particular galaxy is called a lenticular galaxy.

Lenticular galaxies like NGC 6684 (lenticular means lens-shaped) possess a large disc but lack the prominent spiral arms of galaxies like the Andromeda Galaxy. This leaves them somewhere between elliptical galaxies and spiral galaxies, and lends these galaxies a diffuse, ghostly experience. NGC 6684 also lacks the dark dust lanes that thread through other galaxies, adding to its spectral, insubstantial appearance.

The unknown is whether this is the state of a galaxy prior to becoming a spiral, or it is what it looks like as it transitions from a spiral to an elliptical. This particular galaxy is likely the latter, as it lacks the dust, but this does not have to be the rule.