Astro News
- Recent Updates of Astro News
- Active Mercury(07/09)
- Hubble Status Report: Directly Observes a Planet Orbiting Another Star(01/09)
- A Non-trivial Answer to a Trivial Astronomical Question-The Origin Of Absolute Magnitude(07/08)
- Assault by a Black Hole(04/08)
- New Lakes Discovered on Titan(01/08)
- ˇ§Deviant Behaviourˇ¨ in the Solar System(10/07)
- Cosmic Ripples - Cosmic Microwave Background - CMB(07/07)
- Interplanetary Superhighway(04/07)
- Is Pluto a Planet?(01/07)
- Breathing Moonrocks(10/06)
- My Thoughts on the Theory of Relativity, Quantum Mechanics, Superstring Theory and Dark Matter(07/06)
- Space-time Vortex(04/06)
- Radio Astronomy(01/06)
- Neutrino Astronomy(10/05)
- The Active Earth(07/05)
- What is Dark Energy?(04/05)
- The Mysterious Black Holes(01/05)
- Intermediate-Mass Black Holes And Quasisoft X-Ray Sources(10/04)
- Time Travel: From a Scientific Approach(07/04)
- What is Astrobiology?(04/04)
- Black Hole: From Fantasy To Reality (II)(01/04)
- Black Hole: From Fantasy To Reality (I)(10/03)
- From The Oldest Light In The Universe To The Fate Of The Universe(7/03)
- The Cosmic HERO(4/03)
- Quaoar - the Tenth Member of the Solar System?(1/03)
- The First Chinese Telescope in Space(10/02)
- Diamonds and Other Stardust(7/02)
- Supermassive Black Hole in Andromeda Galaxy(4/02)
- Detection of Solar Neutrinos(1/02)
- Simultaneous Multiple Wavwlength Observation(10/01)
- Celestial Distance(7/01)
- Solar-Terrestrial Relations(7/00)
- Fundamental Particles in Astronomy(4/00)
- The Solar Maximum in 2000(1/00)
- Hubble Constant(10/99)
- New Findings on Cosmology(7/99)
- Strange Stars(4/99)
- How Strong Stellar Magnetic Field Can Be?(1/99)



Important notices






What is a Hero? Hero is actually hard to define. According to Webster: a hero is "a man admired for his courage, achievement and noble qualities and considered a model or ideal", or else "a mythological or legendary figure endowed with great strength and ability, favoured by the Gods....". No matter what definition, in peace time or in reality, a hero is difficult to find. They only appear in novels, fictions, legends, comics or movies.

In the 201st meeting of the American Astronomical Society held in Seattle in 7th January 2003, Myungshin Im, a Caltech astronomer, announced that he had finally found a HERO in deep space and that HERO may shed light on the real nature of HERO.

The above HERO is merely an acronym, an abbreviated form of Hyper Extremely Red Object. Grammatically, the adverbial use of "hyper extremely" seems unusual. It is because the term "Extremely Red Object" or "HERO has already been used by astronomers to identify the extremely red object in the universe. HERO is merely a celestial object that is redder than the extremely red ERO.

The term HERO was coined by a Kyoto University astronomer, T. Maihara. He identified some objects in the Subaru Deep Field (SDF) that were redder than the usual EROs. The Subaru Deep Field was taken in 1999 with the Subaru Telescope while aiming at a small patch of the sky in Coma Berenices and exposing for 1.33 hours. Having a 8.2 metre mammoth mirror, the Subaru Telescope is located on the summit of the 4,200 m Mauna Kea Observatory in Hawaii. These HEROs conceal themselves invisible in the visible range of the spectrum, but they were visible in the near infrared range. From the enormous redshifts of their spectra, astronomers deduced that they are receding at very fast velocity from us. According to Hubble's Law, they are also very far from us.

Using data from Subaru and also the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) of the Hubble Space Telescope, Im recently located one HERO and 3 possible HERO candidates in the boundary region of the constellations Hercules and Draco. They are in the vicinity of the radio galaxy 53W002, whose spectrum revealed that it is about 10,000 million (10 billion or 10,000,000,000) light-years away from us.

There are two possible causes for the extremely red colour of these HEROs, say Im. They might be: 

  1. Extremely distant galaxies - as previously supposed, they are extremely distant galaxies. Their huge redshifts are due to cosmological red shif. Their estimated distance might be 13,000 millions ( or 13 billion) light-years.

  2. Much closer galaxies - they are closer than previous supposed (not al all close! In the range of 10,000 million or 10m billion light-years). Their light are cloured red simply because of huge reservoir of dust obscuring our view. These galaxies might perhaps be starburst galaxies, galaxies in a stage of formation when they are still cocooned by enormous envelopes of dust.

Im now had plans to check out the four HEROs in the SDF using NASA's new Space Infrared Telescope Facility (SIRTF), originally scheduled to be launched in April. However, he already suspects that they are reddened by dust. If they were instead very remote, it would be statistically very unlikely to find four of them so close to an unrelated radio galaxy. Im believed that the four HEROs are probably part of the same cluster of galaxies to which 53W002 belongs.

Two astronomers at the University of British Columbia observed the Subaru Deep Field HEROs with the submillimetre SCUBA camera at the James Clerk Maxwell Telescope (a 15 metre aperture radio telescope), also on Mauna Kea. Relatively close, dusty galaxies are expected to be much brighter at millimetre wavelengths than extremely remote, highly redshifted galaxies. When all four HEROs turned up as expected in the SCUBA observations, they concluded that they are dusty star-forming galaxies at a mere 10,000 million (or 10 billion) light-years.

So is the mystery of HERO revealed at last? This is too early to speculate. Astronomers are waiting for more HEROs to be discovered by the next generation of space telescope and the successor of the Hubble Space Telescope, the James Webb Space Telescope. With its more sensitive detector and larger aperture, it could detect more distant galaxies and measure their redshifts more accurately.


Boundary region of constallations Hercules & Draco

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Photo Credit: NASA

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