Bakersfield College

Bakersfield Night Sky -- July 5, 2014

Bakersfield Night Sky – July 5, 2014
By Nick Strobel

Be sure to check out the free public star party tonight (July 5th) at Panorama Park near where Linden Ave meets Panorama Drive (just west of Greenlawn Mortuary/Cemetery) from 8 to 10 PM, depending on weather. The freepublic star party is hosted by the Kern Astronomical Society and the members will be more than happy to show you some nice sights up in the sky. Last month's star party was very well-attended which pleased the KAS members.

The star chart below shows the evening sky at 9 PM when the sky will be dark enough to pick out the stars in the constellations. By then, Jupiter will be too close to the western horizon to see in the Bakersfield haze, so be sure to check it out near the beginning of the public star party. Also, the Beehive Cluster in Cancer will be best seen near the beginning of the public star party.

The stars of the evening (yes, pun intended) will be the Moon, Mars, and Saturn. The Moon will have passed just under Mars at 5:15 PM today and by the time of the public star party the Moon will about a thumb's width at arm's length to the left of Mars. The Moon is one day past First Quarter phase. The bright star just left of the Moon will be Spica at the east edge of Virgo. Above the Moon and Spica in Virgo will be the brightest asteroid Vesta and the largest asteroid, dwarf planet Ceres, very close together on our sky (but about 53 million miles apart from each other in space). The inset of the attached star chart shows their location in the sky compared to the Moon and Mars but you'll need to use the KAS telescopes to see them, though. Earlier this year we discovered that Ceres has a thin atmosphere made of water vapor, possibly from outgassing of water in its interior. The Dawn spacecraft will arrive at Ceres in the spring of next year to study this water vapor atmosphere and the geology of Ceres. Very likely Ceres has more water than all the Earth's oceans combined but it is frozen solid.

Due south at 9 PM is the bright planet Saturn, a beautiful sight in the KAS telescopes. You should be able to pick out Saturn's largest moon, Titan. Titan is the only moon in our solar system with a thick atmosphere. Its atmosphere is mostly nitrogen with a smoggy mix of methane and other hydrocarbons that covers a surface with remarkably Earth-like formations such as mountains, lakes, rivers, dunes, etc. Titan is so cold that its mountains are made of super-hard frozen water and its lakes and rivers are made of liquid methane and ethane.

Straight overhead will be the kite-shaped Bootes with the brilliant Arcturus at its base. To the left of Bootes is the bowtie at the middle of Hercules. Be sure to check out the famous Hercules globular cluster, M13, through the KAS telescopes. We're far enough into the summer that we can see most of the stars of Scorpius at a decent time of night. The bright red-orange Antares is at the heart of the scorpion. Toward the end of the public star party you may be able to pick out the teapot part of Sagittarius. Just off the spout of the teapot is the direction toward the center of our galaxy, the Milky Way. In the east will be the stars of the Summer Triangle: Deneb in Cygnus, Vega in Lyra, and Altair in Aquila.

In astronomy research news, there is some doubt now about whether the recently heralded proof of the Inflation event in the early universe's history is actually as good as we thought in March. It looks like the model the researchers used to distinguish the microwave energy of the dust of the Milky Way from the microwaves of the cosmic microwave background has some flaws. The cosmic microwave background is coming from when the universe was just 380,000 years old but it contains information from an event happening within a fraction of a second after the start of the expansion of the universe called "Inflation". More up-to-date models of the Milky Way dust effect seem to show that the effect the BICEP2 research found in March is probably due mostly to contamination from the Milky Way dust. Notice that the words I use are not definitive ones. That's because the other research teams that recently showed that the BICEP2 proof of Inflation in March is not that conclusive had to do some extrapolating themselves. All the teams are working with the best information they have at the time and the effects they are looking for are extremely hard to find. This is the incremental type progress that is typical of science.

The research teams are using preliminary models from the Planck spacecraft mission of the various microwave contamination effects. Planck finished mapping the cosmic microwave background to very high precision last year and the Planck research team continues to analyze all of the data. The final model of the microwave contamination should be finished by the end of this year and only after that point will we know for sure whether or not the BICEP2 really found the proof of Inflation (and get the Nobel prize in Physics).

A bit closer to home was the news report about a galaxy with not one supermassive black hole but three near its center. The galaxy is "only" 4.3 billion light years from us. Although it is not the first triple black hole found, this galaxy's triple supermassive black hole system are the closest spaced triple system found so far. Since most galaxies have just one supermassive black hole at their centers, this triple black hole system is very likely the result of galaxy mergers of three galaxies.

Much closer to home was the recent report about Gliese 832c, a super-Earth orbiting the faint red-dwarf star Gliese 832 just 16 light years away. In the context of exoplanet research, a "super-Earth" is defined by mass only: a world up to ten times the mass of Earth. The term does not necessarily mean the planet is habitable. This super-Earth orbits in the habitable zone of Gliese 832, so it is among the closest possibly habitable world. Since it has at least 5.4 times the mass of Earth, it might have a very thick atmosphere that could trap too much heat through the greenhouse effect to enable water to exist on its surface. Instead of a super-Earth, it could be a super-Venus.

The seasons on Gliese 832c may be extreme since it has a very elliptical orbit. At closest approach to the star, it is at the inner (hot) edge of the star's habitable zone and at farthest distance it is comfortably within the habitable zone. However, it takes less than 36 days to orbit Gliese 832 so the planet might not have time to really heat up or to cool off significantly. It depends on the atmosphere which we still have to study.

Also in the recent news was an even closer exoplanet in its star's habitable zone Kapteyn b. Kapteyn's star is just 12.7 light years away from us. Besides being the closest habitable zone exoplanet, Kapteyn b, is the oldest known habitable exoplanet found so far. Kapteyn's star is about 11.5 billion years old, so Kepteyn b is over twice as old as the Earth. That's plenty of time for an advanced, intelligent civilization to develop. Kapteyn b is at least 4.8 times the mass of the Earth, so it too, is a "super-Earth". Future research will try to determine the nature of Kapteyn b's atmosphere, and, therefore, how habitable it actually is. Right now, we just know the exoplanet's mass, orbit around Kapteyn's star, and its distance from us. More to come!

What would we look for to find out if there's life on an exoplanet? We'd analyze the exoplanet's atmosphere to see if life has changed the chemistry to an out-of-equilibrium state beyond the usual carbon dioxide or nitrogen rich atmosphere we find on Venus, Mars, and Titan. Something like having a lot of free molecular oxygen or ozone in the atmosphere could indicate the presence of life. That's because oxygen and ozone molecules would quickly combine with other molecules and disappear from the atmosphere unless something keeps regenerating the oxygen/ozone. However, it is possible to generate a lot of oxygen from the break up of carbon dioxide or water molecules in an atmosphere by ultraviolet light from the star. If the star produces a large amount of very short wavelength ultraviolet light, it could produce a lot of oxygen that is not from biological activity. Astronomers have to know the ultraviolet environment of the exoplanet and measure the relative amounts of other molecules such as methane, nitrous oxide, carbon dioxide, and water in the exoplanet's atmosphere to decide whether or not the abundance of oxygen/ozone is due to life. The upcoming James Webb Space Telescope might be able to measure the nearby exoplanet atmospheres and the proposed Terrestrial Planet Finder (not funded) would definitely be able to do that.

Want to see more of the stars at night and save energy? Shield your lights so that the light only goes down toward the ground. See www.darksky.org for how.

--
Nick Strobel
Director of the William M Thomas Planetarium at Bakersfield College
Author of the award-winning website www.astronomynotes.com

Early July 2015 at 9 PM looking west with Ceres/Vesta inset

Kern Community College District