Mountain Views News          Saturday, September 13, 2014

B2

THE WORLD AROUND US

Mountain Views-News Saturday, September 13, 2014 


Half of All Exoplanet Host Stars Are Binaries


Imagine living on a planet that has two suns. One 
you orbit, and the other is a very bright, nearby 
neighbor looming large in your sky. With this 
�second sun� in the sky, nightfall might be a rare 
event, perhaps only coming seasonally to your 
planet. A new study suggests that this could be far 
more common than we realized.

 NASA�s Kepler Space Telescope has confirmed 
about 1,000 exoplanets. Until now, there has been 
an unanswered question about exoplanet host 
stars: how many host stars are binaries, or double 
stars? Binary stars have long been known to be 
commonplace�about half the stars in the sky are 
believed to consist of two stars orbiting each other. 
So, are stars with planets equally likely to have a 
companion star, or do companion stars prevent the 
formation of planets? 

 The study, by a team of astronomers led by 
Dr. Elliott Horch, Southern Connecticut State 
University, has shown that stars with exoplanets 
are just as likely to have a binary companion: 40% 
to 50% of the host stars of confirmed exoplanets 
are actually binary stars.

 Their study makes use of very high spatial 
resolution observations that were carried out on the 
WIYN telescope located on Kitt Peak in southern 
Arizona and the Gemini North telescope located 
on Mauna Kea in Hawaii. The technique used by 
the team is called speckle imaging and consists of 
obtaining digital images (15 to 25 times a second) 
of a small portion of the sky surrounding a star of 
interest. The images are then combined in software 
using a complex set of algorithms, yielding a final 
picture of the star with a resolution better that that 
of the Hubble Space Telescope. 

 By using this technique, the team can detect 
companion stars that are up to 125 times fainter 
than the target but only 0.05 arcsecond away. 
For the majority of the Kepler stars, this means 
companion stars with a true separation of a few to 
about 100 times the Sun-Earth distance. By noting 
the occurrence rate of these true binary companion 
stars, the discoveries can be extended to show that 
half of the stars that host exoplanets are probably 
binaries.

 Co-author of the study, Dr. Steve B. Howell 
(NASA Ames Research Center), commented, �An 
interesting consequence of this finding is that in 
the half of the exoplanet host stars that are binary 
we can not, in general, say which star in the system 
the planet actually orbits.�

 The Kepler orbiting telescope has discovered a 
number of circumbinary planets, that is, a planet 
that orbits both stars in very close binary systems. 
There also exist exoplanets that are known to orbit 
one of the stars in very wide binary systems. If 
the two stars are very close to each other and the 
planet far away, a circumbinary planet will be 
reminiscent of the planet Tatooine in �Star Wars.� 
If instead the exoplanet orbits one of the stars in a 
very wide pair, the companion star might appear 
simply as a bright star among others in the night 
sky. �Somewhere there will be a transition between 
these two scenarios,� Howell said, �but we are far 
from knowing where.�

 The accompanying figure marks out the Kepler 
Space Telescope�s field of view (the part of the sky 
being studied here), located between two bright 
stars in the �summer triangle,� rising over the Kitt 
Peak telescope in southern Arizona.

 

You can contact Bob Eklund at: b.eklund@
MtnViewsNews.com.

PLANTING TREES IN SIERRA MADRE TO FIGHT DROUGHT By Christopher Nyerges


Trees, grey water recycling, and welcoming the rain are all needed Low-tech solutions to Urban Density

We are not 
advocates of the 
�front lawn.� 
Our front area 
is planted with 
fruit trees, 
herbs, and 
ornamentals. 
Once, while we 
were tending 
this area, a 
visitor of ours 
stated that he does not grow anything in his 
yard. He told us he was so concerned about dry 
weather conditions, and drought conditions, 
that he regarded any sort of plant cultivation as 
�wasting water.� 

 Of course, our visitor was tacitly suggesting 
that we were wasting water. 

 We realized that this idea was rather 
widespread when yet a second person suggested 
that we forget about planting any more trees, 
bushes, or vegetables due to what seems to be 
regular periods of drought and water shortages 
in Southern California. 

 This counter-productive idea seems to have 
gained a foothold in the minds of many residents 
of our Southland. We�ve even heard some �garden 
experts� suggest this idea, that to �save water� we 
should simply not grow plants. 

We are able to grow fruit trees and roses and 
herbs and other edible plants partly because we 
direct all of our washing machine water, and 
most of our dish water, out into the garden areas 
and not down the city�s sewer line. We are using 
the water twice! 

 To the visitor who suggested that we stop 
growing for awhile, we casually asked, as we were 
showing him our water recycling system, �So 
where does all your used water go?� He was silent 
for a moment, and then told us that it all goes into 
the sewer. 

 In fact, with careful attention to the type of 
detergents purchased, we can direct virtually 
all of our water into our yards. This is done in 
many possible ways. The dish basin, full of used 
water, can simply be carried outside and poured 
manually around your plants. Or you can fill 
one gallon plastic buckets with your used bath, 
shower, or dish water, and then carry it outside to 
where it is needed. With a bit more work, you can 
disconnect from your sewer line and permanently 
direct all of your used water into your own yard, 
as we�ve done with the washing machine. 

 There are two major benefits of sending your 
used household water into your own yards, rather 
than letting it flow unceremoniously down the 
sewer. 

 As more and more people move into this coastal 
mountain-locked desert plain, we have quickly 
begun to use the water faster than nature�s ability 
to replenish the supply. Thus, our underground 
water table has steadily dropped. Directing all 
our household water into our yards could have at 
least a minimal positive affect on the water table 
(as long as we avoid bleaches and dyes in our 
detergents that could be harmful to the soil and 
water). 

 More importantly, one of the best �weapons� 
to combat desertification and the serious effects 
of the cycles of drought is the presence of trees! 
Throughout recorded history, the harvest and 
non-replenishment of trees has led to weather 
changes that have resulted in large deserts. All 
the major deserts on earth were once forests, but 
the trees were cut down for making boats or other 
products. Conversely, since the transpiration 
cycle of trees releases large amounts of water 
into the environment, the planting of trees on a 
large scale can reduce the effects of drought, can 
alter weather and can reverse the downward cycle 
towards desertification.

 We don�t want to stop our efforts to plant -- and 
to nurture -- trees just because there is a period 
of drought. But we must do so wisely. By using 
all possible grey water, we�re able to keep our 
necessary trees and plants alive and transpiring. 

 When we read that the average residence of Los 
Angeles County uses about 400 gallons a day, we 
were astounded. We�re not sure what constitutes 
an �average� family, but when we average out out 
water usage, it doesn�t come close to 400 gallons 
on a daily basis. Imagine how astounded we 
both were to learn that Hugh Hefner�s Playboy 
mansion uses 25,000 gallons of water daily!! Or 
that the Hotel Bel-Air, an 11 acre retreat, uses 
98,000 gallons a day! 

 No wonder we have water troubles. People flock 
her to the desert and they use water profligately, 
as if they were living in Canada or the Rockies or 
some other water-rich environment. 

With all this in mind, we wonder: 

* Where doesn�t every single family residence 
in Southern California direct all their own gray 
water into their own yard? This raises the water 
table, and allows plants to grow with water that 
was already used and paid for? 

* Why isn�t the city, or various water agencies, 
actively promoting not just low-flush toilets but 
composting toilets, which use NO water at all? 

* Why does the average residence pay more for 
the water they so-carefully use, when the �big 
users� get to buy their water wholesale? 

* Why do we allow any new construction at 
all, either residential or business? If our water 
situation is only going to get worse as population 
increases, shouldn�t we take some steps to 
encourage development elsewhere? Or are we 
so caught up in the suicidal money-making 
mindset that �development is always good for 
business� that we are blind to what we are doing 
to ourselves? 

 We know that there are countless other �easy� 
and practical ways to fight water shortages and to 
live lightly on the earth. 

 Another deep-seated idea that all should root 
out of our thinking is that �Sunny weather is 
good weather, and rainy weather is bad.� Most 
Southern California weather reporters have 
interpreted the weather this way for decades 
(with a few rare exceptions, such as the former 
television meteorologist Dr. George Fischbeck). 
Though we are not badmouthing sunny weather, 
we need to begin to think about rain as a valuable, 
friendly, needed gift from heaven, without which 
our home here between the sea and the mountains 
would quickly revert to a semi-barren desert.

 

 [Nyerges is the author of Extreme Simplicity: 
Homesteading in the City (along with his wife 
Dolores). Nyerges operates the School of Self-
reliance, offering classes in self-reliance and 
survival. The web site is www.self-reliance.net. 
Nyerges is also a member of the Highland Park-
based WTI (www.wtinc.info), which teaches city 
dwellers how to live better with less.]