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Planck 2013 results

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Astronomy & Astrophysics is publishing a special feature of 31 articles describing the data gathered by Planck over 15 months of observations and released by ESA and the Planck Collaboration in March 2013. This series of papers presents the initial scientific results extracted from this first Planck dataset.

The Planck satellite was launched in May 2009. With the highest accuracy to date, it measures the remnants of the radiation that filled the Universe immediately after the Big Bang. It is the oldest light in the Universe, emitted when it was 380000 years old. This light is observed today as the cosmic microwave background (CMB). Its maximum intensity is at about 150 GHz (2 mm), and its temperature about 3K. The study of the CMB is currently a very active field of research in cosmology because it provides strong constraints on the cosmological models. In particular, observations of the CMB confirms the key prediction of the Big Bang model and, more precisely, of what cosmologists call the concordance model of cosmology.

Planck was designed to measure the emission from the entire sky at nine distinct wavelengths, ranging from the radio (1 cm) to the far-infrared (300 microns). Several distinct sources of emission both of Galactic and extragalactic origin contribute to the features observed in each of the nine images shown here. Radio emissions from the Milky Way are most prominent at the longest wavelengths, and thermal dust emission at the shortest. Other galaxies contribute to the mix, mostly as unresolved sources. In the middle of Planck's wavelength range, the CMB dominates the sky at intermediate and high Galactic latitudes. The spectral and spatial signatures of all these sources are used to extract an all-sky image of the tiny temperature anisotropies of the CMB with unprecedented accuracy. The properties of these fluctuations are used to derive the parameters characterizing our Universe at early times.

Papers II to X in the series describe the huge dataset obtained from the Planck satellite and released in March 2013. Using this dataset, the Planck team established the new "cosmic recipe," i.e., the relative proportions of the Universe's constituent ingredients. Normal matter that makes up stars and galaxies contributes just 4.9% of the energy of the Universe. Dark matter, to date detected only indirectly by its gravitational influence on galaxies and galaxy clusters, is found to make up 26.8%, more than previous estimates. Conversely, dark energy, a mysterious force said to be responsible for accelerating the expansion of the Universe, accounts for 68.3%, less than previously thought. The Planck team also published a new value for the age of the Universe: 13.8 billion years (see Paper XVI).

The Planck team also studied the statistical properties of the CMB in great detail. Papers XXIII, XXIV, and XXVI explore the statistical distribution of its temperature anisotropies. There is no evidence of any deviations from isotropy on small angular scales. While the observations on small and intermediate angular scales agree extremely well with the model predictions, Planck has now provided the first indisputable evidence that the distribution of primordial fluctuations was not the same on all scales and that it comprises more structure than expected at larger scales. One anomalous signal appears as a substantial asymmetry in the CMB signal observed in the two opposite hemispheres of the sky, which is that one of the two hemispheres appears to have a significantly stronger signal on average. Among the other major results, Paper XXIII of the series explores how the Planck data can constrain theories of cosmic inflation; this paper currently puts the tightest constraints on inflation.

The CMB is not only a picture of the Universe taken 13.8 billion years ago, but it was also distorted during its journey because the CMB photons interacted with the large-scale structures that they traveled through (such as galaxy and galaxy clusters). In Paper XVII of the series, the team extracts from the Planck data a map of the gravitational lensing effect visible today in the CMB and covering the whole sky. The map published in this paper provides a new way to probe the evolution of structures in the Universe over its lifetime.

A byproduct of the Planck all-sky maps are catalogs of compact sources. Paper XXIX describes the production of the largest catalog of galaxy clusters based on the Sunyaev-Zeldovich effect, a distortion of the CMB spectrum caused by very energetic electrons in a galaxy cluster, which kick CMB photons to higher energies. This catalog was used to estimate cosmological constraints, as described in Paper XX.

With the 2013 release of the intensity signal measured during the 15 first months of observation, Planck data are providing new major advances in different domains of cosmology and astrophysics. In the very near future, the Planck Collaboration will release a new dataset that includes all of its observations in intensity and in polarization. This new dataset will be a lasting legacy for the community for many years to come.

Further information: http://www.aanda.org/index.php?option=com_toc&url=/articles/aa/abs/2014/11/contents/contents.html

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Planck 2013 results

Astronomy students experience eclipse

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Teens typically put glasses on to block the sun, not stare at it. But thats just what students in Steven Harness astronomy class at Kingsburg High School were doing during a recent partial solar eclipse.

Its actually pretty awesome, said freshman Marcus Reyes, 14, donning the special glasses that protect a viewers' eyes so they can look directly at the sun without damaging them. Its about 20 percent covered right now.

Harness students and Scott Silva, a member of Fresno's Central Valley Astronomers Club, set up four eight-inch wide reflector telescopes and sun spotters and donned eclipse shades to take advantage of the rare event Oct. 23.

This doesnt happen very often, so its something to see, Silva said. Itll last for only about an hour.

As teachers led their students out for brief turns peering into the view lenses, students and faculty alike took advantage of the ability to take pictures on their cell phones through the eclipse shades.

Its hard because of the light, senior Kristopher Dy, 18, said. It has to be completely dark to make (the sunspots) out. To see an actual eclipse is pretty rare where we live.

According to a NASA education website, the partial solar eclipse was visible as far north as the Arctic, as far south as Mexico and could be seen from the east to west coasts. Solar eclipses occur when the moon moves between the sun and Earth and blocks the light of the sun from reaching Earth. The moon also winds up casting a shadow on to the Earth at that time.

Harness freshmen students are learning about lunar eclipses and moon phases while English instructors are focusing on Greek mythology and constellation name sources in their classes.

Science students also get to examine moon rock samples and meteorites on loan from NASA during class, Harness said.

Were learning about space, time zones, the positions of the stars and constellations, said senior Matthew Flores, 18. Its interesting to learn about something thats not on this planet.

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Astronomy students experience eclipse

Astronomy – Ch. 6: Telescopes (4 of 21) Converging Lens and Real and Virtual Images – Video

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Astronomy - Ch. 6: Telescopes (4 of 21) Converging Lens and Real and Virtual Images
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain how converging lenses make real and virtual images.

By: Michel van Biezen

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Astronomy - Ch. 6: Telescopes (4 of 21) Converging Lens and Real and Virtual Images - Video

Renamed astrophysics major revamps curriculum

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This semester, changes are afoot in the astronomy department.

In response to student feedback, the department made several changes that will go into effect this year, including changing the name of the Bachelor of Science degree from Astronomy and Physics to Astrophysics. The Bachelor of Arts degree will keep its name of Astronomy. The department has refocused the B.S. major on the core science skills necessary for a career in science, adding new courses like Astrostatistics and Data Mining (ASTR 356), which focuses on statistical analysis. Faculty have also made it a priority to do field work in observatories. Astronomy director of undergraduate studies Debra Fischer also reviewed all of the majors courses, revising the curriculum to eliminate overlap between courses and ensure that the curriculum is in sequential order. According to faculty members interviewed, these changes are geared at better preparing students for careers in science.

I think the redesigned curriculum prepares the students better for anything they want to do, Fischer wrote in an email. They will hit the ground running if they decide to go to grad school.

Victoria Misenti, assistant astronomy DUS, said that the majors former name, Astronomy and Physics, was sometimes mistakenly thought to be a double major. Other professors also said that the majors new name is much stronger.

[Students] didnt feel that the name was clear enough for them to be able to successfully go into graduate programs or professional careers as astronomers, Misenti said. Astrophysics was much stronger it meant something more to these graduate programs.

While Fischer said she is not sure the name change is significant, astronomy professor Louise Edwards said she hopes it will prove important. Edwards added that she hopes the majors new name will help employers recognize that Yales program develops strong analytical skills in its students.

Students are pleased with the changes, Misenti said, adding that while only the Class of 2017 and below need to meet the new set of requirements, most upperclassmen want to anyway. She also noted that the increasing number of majors suggests students are pleased with the changes.

Astronomy and physics major Hannah Alpert 15, who participated in a focus group her sophomore year to discuss possible changes for the major, said she was happy to see that many of the concerns voiced by students in the group had been resolved with the recent changes. Many of her peers desired more intermediate classes before the change, classes were split between lower level introductory classes and higher level classes, she said.

I dont think the changes are very drastic, but noticeable in a good way, Alpert said.

Though she was a part of the focus group, Alpert said she is unaware of what all the changes entail. She added there will be a discussion for undergraduates on Nov. 14 about the changes. A new committee will also be formed to review the current curriculum.

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Renamed astrophysics major revamps curriculum

Cal Poly Shares $1 Million Grant to Fund Citizen Science Astronomy Research

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SAN LUIS OBISPO Cal Poly and the Southwest Research Institute in Boulder, Colo., have received a $1 million collaborative grant from the National Science Foundation to continue a citizen-scientist astronomy project in rural communities in the Western U.S. stretching from the Mexican border to the Canadian border.

More than 40 towns along the eastern edge of the Sierra Nevada and Cascade mountain ranges and down the Colorado River will receive telescopes and training through the grant.

The towns in this second phase of the project will join 13 pilot communities to form the Research and Education Collaborative Occultation Network (RECON). Scientists John Keller, a Cal Poly physics professor, and planetary scientist Marc Buie will lead the network of teachers, students and amateur astronomers in measuring the sizes of Kuiper Belt Objects (KBOs) large, frozen bodies that orbit thesunin the outer region of the solar system.

This project is an innovative and exciting opportunity for students and community members from across the Western U.S. to directly contribute to our understanding of the Kuiper Belt, said Keller.

At predicted times, KBOs that pass between Earth and a given star will hide the star from view, an astronomical event called an occultation. Observers located in the path of a KBOs shadow can record the star blinking out and reappearing. The length of time that the KBO blocks the starlight can be used to determine its size.

Because of the inherent uncertainty in the predicted location of each shadows path, Buie and Keller are recruiting participants along a 1,200-mile stretch from Canada to Mexico.

Buie, from the Southwest Research Institute, has been involved in the discovery of KBOs over the past two decades. Now that we know these objects exist, we want to know more about them, Buie said. Working with our citizen scientists is an effective way to find out the size, shape and several other characteristics of the KBOs we study, which in turn will shed light on the origins of our solar system.

Both Buie and Keller see the benefits of RECON stretching far beyond what scientists will learn about KBOs. These rural cities joining the RECON project are highly underserved communities, Keller said. This makes the excitement of scientific discovery real for a whole network of high school students and citizen scientists.

The town of Hawthorne, Nev., and the Mineral County School District now have a telescope to share for educational and community use, the first time ever, said community member Kathy Trujillo. The high school was able to offer an astronomy class. Imagine the wonder in a students eyes when she sees the rings of Saturn for the first time.

During fall 2014, Keller and Buie will recruit team members through trips to Washington, Oregon, Nevada, Arizona and California. The full network will be up and running byApril 2015.

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Cal Poly Shares $1 Million Grant to Fund Citizen Science Astronomy Research


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