Two separate teams of Astronomers have reached another cool milestone for exoplanetary discovery.
They have for the first time “directly imaged” planets not in our solar system
You may be thinking…What’s this “directly imaged” crap…Astronomer have spotted over 300 exoplanets since the 1990s. There’s been countless news stories about it, right?
That’s true. New planets are found so often these days that it doesn’t even make news splashes anymore.
Up until recently however, all exoplanets have been detected by one or two different techniques. One involves detecting the gravitational tug on a star caused by a nearby unseen object. The other method measures the regular dip in light emitted by a star ostensibly caused by a planet moving between us and the star in its orbit. These techniques work very well but they both find planets based soley on their effect on the star. Actually seeing the light reflected or emitted (infared) from the planet itself has proved devilishly difficult. This challenge has been compared to seeing a lit match next to floodlight from a mile away.
If you follow this stuff closely you may be thinking…been there-read that. Haven’t astronomers made this exact claim before? Yes, they have but until now all have been either proven wrong or they’re waiting for final confirmation. Some recent sightings are in limbo because it hasn’t been determined whether the object is a huge planet or a failed star.
There’s not one way do direct imaging either. Each team did this differently.
Astronomers at the Herzberg Institute of Astrophysics in British Columbia directly imaged 3 planets circling star HR 8799 130 light years away in the constellation Pegasus. They used among other telescopes, the famous Keck scope in Hawaii. Using adaptive optics for low distortion images, they then used a special computer program they call a “software coronagraph” to subtract the sun from the images so the planets could be revealed.
The other team is based at the University of California, Berkeley. They and their international astronomer partners used the Hubble Space Telescope to image the system around a star called Fomalhaut in the constellation Piscis Austrinus.
They didn’t use a software coronagraph, they used an old-fashioned hardware coronagraph. This device basically creates an artificial eclipse by placing a disk in front of a star (usually the sun) and revealing objects close to it that would have otherwise been obscured. In this case a planet was found in the cleared-out section of a massive dust ring around the star. The planet they found has about 3 jupiter masses and an 870 earth-year orbit. They also suspect that it might have an enormous ring around it, dwarfing perhaps Saturn’s.
I could understand how recent image processing advances allowed us to see the 3 exoplanets using the software coronagraph. I don’t understand why it took so long for the hardware version to be used. Perhaps those images needed advanced processing as well?
They call the planet….you guessed it..Fomalhaut-b
Don’t you hate these boring naming conventions? The star is called Fomalhaut so the planet is of course Fomalhaut-b. What would we call aliens from that planet? Fomalhaut-b-eings? I think if you discover something extraordinary or if it’s a first…then you can break with convention and just come up with something unique and interesting like maybe Krypton or Stavromula Beta. 😉
Any who… Dr. Paul Kalas who led the whole team said something that struck me as a tad odd. Regarding the relative proximity of the planet to ours he said it’s…“close enough to contemplate sending spacecraft there.”
Fomalhaut is 25 light years away. That’s about 146,642,400,000,000 miles.
I grant that…cosmically speaking…this is in our back yard but it would take thousands of years for a conventional ship to get there. Even advanced designs beyond our current ability to construct would take centuries. This doesn’t even address the cost of such a mission.
I’d rather fund more science experiments than put the money in a mission that only my great-great-great-great…grandson will appreciate.