Hello Space Fans and welcome to another edition of Space Fan News.
This week, NASA’s rebooted Kepler Space Telescope, known as K2, finds its first group
of new worlds around other stars and astronomers using the Hubble Space Telescope celebrate
the 50th anniversary of Star Trek by releasing its Final Frontier - umm, Field.
If you watch SFN on a regular basis or listen to our podcast This Week in Space Telescopes
on iTunes, then you’ve learned that when the reaction wheels on the Kepler Space Telescope
failed in 2013 astronomers came up with an amazingly novel way to keep Kepler alive and
finding exoplanets.
Calling it K2, astronomers use pressure from the solar wind as a replacement for one of
the reaction wheels that keep the spacecraft pointed.
This technique meant that it could look at other areas of the sky besides Cygnus, the
area the Kepler mission was originally looking at for four years.
So long as that new area of the sky was along the ecliptic plane, that is.
This is the band of sky that lies in the plane of the Earth’s orbit around the Sun.
Using this new configuration, K2 has resumed its search for exoplanets and while the original
Kepler mission found thousands of new worlds around other stars, K2 had yet to announce
any new exoplanet discoveries.
It takes time to find these things, astronomers need a long time-series of observations to
find dips in brightness of any potential host stars.
And while K2 can scan a much larger area of sky than the original Kepler mission could,
this also meant that it took a bit of time to come up with its first candidates.
It’s also interesting to note that K2 is operated more like the Hubble Space Telescope
where the science community proposes for and decides what targets to look at.
Well this week marked the end of the long wait, and K2 came in with a bang, finding
197 exoplanet candidates.
These were objects whose transit light curve suggested that there might be a planet in
orbit around those stars.
Candidates are not considered exoplanets until they are confirmed by more observations, usually
from the ground, and from these 197 candidates, astronomers from the Keck Observatory on Mauna
kea, the twin Gemini telescopes on Mauna kea and in Chile, the Automated Planet Finder
of the University of California Observatories and the Large Binocular Telescope operated
by the University of Arizona confirmed 104 of them.
One of the most interesting set of planets discovered in this study is a system of four
potentially rocky planets, that are between 20 and 50 percent larger than Earth, orbiting
the M dwarf star K2-72, which is 181 light years away in the direction of the constellation
Aquarius.
The orbital periods of these worlds range from five-and-a-half to 24 days, and two of
them may experience radiation levels from their star comparable to those on Earth.
These guys have tight orbits — they are closer than Mercury's orbit around the sun.
Still, the possibility that life could arise on a planet around such a star can’t be
ruled out,
Many exoplanet astronomers believe that red dwarf stars are the best place to look for
planets that might harbor life.
They are very stable stars - they last trillions of years - and while they are dimmer than
our sun, this has the added bonus that the radiation environment is also calmer and perhaps
more friendly to life.
So for our search for life, astronomers believe we should be focusing heavily on red dwarf
stars.
Kepler’s original mission stared at one spot in the sky in the constellation Cygnus
for four years looking for tiny dips in brightness, and as I said, it was very successful.
But that approach effectively meant that relatively few of the brightest, closest red dwarfs were
included in Kepler's original survey.
The K2 mission allows astronomers to increase the number of small, red stars by a factor
of 20 for further study.
So not only am I amazed at the extremely ingenious way that astronomers and engineers have revived
K2 and kept our search of exoplanets alive until the launch of TESS in about a year,
I am also extremely excited about the potential for new worlds that K2 observations will provide.
I’m watching this mission very closely.
Next, while I’m trying really hard not to think about the fact that my beloved Star
Trek has been around for 50 years (!) I had to smile this week, when astronomers using
the Hubble Space Telescope released this image of the Final Frontier - uh Field.
Frontier Fields is a three year campaign that’s just ending that used hundreds of orbits to
look very closely at six areas of the sky and six galaxy clusters to provide a glimpse
of the early universe.
Astronomers wanted to get an idea of the kind of galaxies that made up the early universe
and since Hubble isn’t powerful enough to see as far back as, say the James Webb Space
Telescope will be able to, it boosted its power a little by using relatively nearby
galaxy clusters as lenses to allow Hubble to see even further back than it ever had
before.
But that’s not all it was doing.
Being the clever people that they are, astronomers made the most of these hundreds of Hubble
orbits by also imaging a nearby patch of sky in the same field of view as the galaxy cluster.
By staring at six different patches of sky at the same time they were looking at the
galaxy cluster, astronomers were able to build up essentially six additional Hubble Deep
Fields.
They wanted to know if the distribution of galaxies was more or less the same in all
of these parts of the sky.
So this image is the last of the six clusters to be completely imaged by the Frontier Fields
Survey.
This cluster is called Abell S1063 and the image next to it is the parallel field.
Located some four billion light years away, Abell S1063 a confirmed 51 galaxies with perhaps
over 400 more and weighing in at 100 million million solar masses.
The stretched out arcs are very distant, gravitationally lensed galaxies that are distorted by the
gravity of the foreground cluster.
One of these galaxies is an infant, from a time when the universe was only 1 billion
years old.
This galaxy could not be seen without the help of the foreground cluster amplifying
the feeble signal from this tiny galaxy.
Taken as a whole and in honor of the latest Star Trek movie Star Trek Beyond, astronomers
are calling the Abell S1063 cluster a warp field.
An image where spacetime is bent and light is molded by the shape of the universe.
Sadly, as much as I love Hubble, you won’t find a bigger Hubble Hugger than me, it can’t
do anything to get us any closer to these galaxies or bring the universe closer quite
like the Enterprise can.
Still, it’s a pretty cool image from an amazing telescope that is still doing really
cool things.
Well, that’s it for this week Space Fans.
Thanks to all Patreon Patrons for helping make SFN possible, thank you all for watching
and as always Keep Looking Up!