Hubble is back! and it’s better than ever!
Last May, the Space Shuttle Atlantis was launched to carry out the final servicing mission of our beloved Hubble Space Telescope. After three months of focusing, testing and instruments calibrating, Hubble is back and is now ready for full science observations!
Let’s take a look at the images just released from the rejuvenated space telescope.
Colorful Stars Galore Inside Globular Star Cluster Omega Centauri
This is the famous globular cluster Omega Centauri, zoom in to the very core of the giant cluster. This is taken by the Wide Field Camera 3 (WFC3) which replaced the Wide Field and Planetary Camera 2 (WFPC2).
There are 100,000 stars in this small crowded region. How crowded? Look at the centre of this image and you get an idea how packed it is. But with Hubble new sharp eye, we are able to resolve them into individual colourful stars.
The different colours of the stars show them to be at different stages of their life, from yellow-white “normal” stars like our Sun, to red-giant as they become bigger and cooler later in their life. There are also these blue stars which are either struggling to stay alive by fusing helium in their core or are the so-called “blue stragglers” which are older stars that acquire a new lease on life when they collide and merge with other stars. There are also white dwarfs (stars like our Sun at the end of their life) visible as faint blue dots in the image.
Butterfly Emerges from Stellar Demise in Planetary Nebula NGC 6302
Credit: NASA, ESA, and the Hubble SM4 ERO Team
This is another image from WFC3 – the Butterfly Nebula in Scorpius. The delicate beautiful wings are actually gases heated to more than 20,000 degree Celcius and are racing across space at 1 million km per hour! Fast enough to travel to the Moon in 24 minute.
The gases were ejected by a dying star at the centre. This red-giant was once about five times the mass of our Sun. The star itself is not visible – it is hidden within a doughnut-shaped ring of dust. Click here to see the “before” image.
One of the great features of WFC3 is its ability to see from near infrared through visible light and into the near ultraviolet. This allows Hubble not just seeing deeper into the universe but also seeing simultaneously in different “colours”. This is important because different wavelength of light will give us different views and information on the same object. The next image clearly illustrates this.
Stars Bursting to Life in the Chaotic Carina Nebula
This image shows pillar of gas and dust resides in the Carina Nebula. The top image was taken in visible light, showing the glow of light from hot, massive stars. Streamers of gas and dust can also be seen flowing off the top of the pillar. At the dark notch in centre of the pillar, we saw some evidences of a young star blowing jets, but the star itself is invisible. Looking in visible light, the clouds is opaque – we can’t see what’s inside (or behind) the clouds.
But if we look at different wavelength – as shown in the near-infrared image at the bottom of the image above – the gas and dust “disappeared” and only a faint outline of the pillar remains. Infrared light, unlike visible light, can pass through the clouds easily. By penetrating the wall of gas and dust, the infrared vision of WFC3 reveals the infant star that is probably blasting the jet.
Galactic Wreckage in Stephan’s Quintet
Another one from WFC3. This group of galaxies is known as Stephan’s Quintet, or Hickson Compact Group 92. It shows a clash among galaxies, which is quite common in the universe. You can clearly see the distortion, elongated spiral arms and long tidal tails among the three galaxies at the centre and top. But why do the upper left one looks undisturbed? Because it has nothing to do with the group. It is just a chance alignment along our line of sight. NGC7320 is actually a foreground galaxy about seven times closer to Earth than the rest of the group.
Other amazing images came from the Space Telescope Imaging Spectrograph (STIS) and the Advanced Camera for Surveys (ACS). STIS was dead in 2004 and ACS in 2007, both due to electronic short circuits. These two instruments were brought back to life during the Servicing Mission 4 last May. It was a great challenge to repair these instruments because they are not meant to be repaired in orbit at the first place. For example, to repair STIS, astronauts had to remove 111 screws to allow access to the failed power converter.
The repairs were a success. Both the instruments are now working splendidly.
Gravitational Lensing in Galaxy Cluster Abell 370
See the arcs and streaks in the image above? These are actually galaxies behind this galaxy cluster. The stretched images of background galaxies are due to a phenomenon called gravitational lensing. According to Einstein, mass wraps space. The warping of space by the massive cluster’s gravitational field acts like a lens (thus the name gravitational lensing), magnifies the image of galaxies lying far behind it and distorts their light, often making them look like an arc. Located at 2 o’clock position in the image above is one prominent example of the arc.
Probing the Last Gasps of the Doomed Star Eta Carinae
This is a spectrum of one of Eta Carinae’s giant lobes taken by STIS. Spectrum, the colourful strip in the image above, is the separation of light into its component colour. Spectrum is very useful because it can tell us a lot about the chemical content, temperature and motion of an object in the sky. From this spectrum, we identify iron and nickel in the outer material and found that the interior material is carried away by the ongoing wind from Eta Car A, the primary star.
Last but no least, a beautiful face-on spiral galaxy in Ursa Minor:
Source: HubbleSite NewsCenter
Hubblecast by ESA – Rebirth of an Icon
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