Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The LBT gets polarized: First light for the PEPSI polarimeters

13.10.2017

Thanks to a cleverly designed "two-in-one" instrument attached to the world's most powerful telescope, astronomers can extract more clues about the properties of distant stars or exoplanets than previously possible.

Developed at the Leibniz-Institute for Astrophysics in Potsdam, Germany, the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) saw first light on April 1, 2015, after being successfully installed at the Large Binocular Telescope Observatory (LBTO) in Arizona, USA.


First polarimetric spectrum from PEPSI, for the star gamma Equ. The black line is the PEPSI spectrum and the red line is, for comparison, the HARPS-Pol spectrum.

Ilya Ilyin/AIP


The two polarimeters SX (left side) and DX (right side) at the two LBT eyes.

Klaus Strassmeier/AIP

Once both of PEPSI's polarimeters were mounted in the focus points of each of the LBT's two 8.4-meter mirrors in late September 2017, the telescope was pointed to the star gamma Equ and polarized light was received. From these spectra astronomers can, for example, deduce the geometry and strength of magnetic fields on the surfaces of distant stars, or study the reflected light from the atmospheres of potentially habitable exoplanets.

A polarimeter separates starlight according to its oscillation planes. It is complementary to a spectrograph that, like a prism, separates light according to its oscillation frequencies (or colour). The two combined, polarimeter and spectrograph, added to a powerful telescope, enable astronomers to obtain spectra in polarized light. This in turn allows the characterization of the full wave-front of the incoming stellar light and extract details of its radiation physics that otherwise remain hidden.

A series of integrations in circularly and linearly polarized light was obtained when the telescope was pointed to the magnetic reference star Gamma Equulei, or gamma Equ, a double star located about 118 light-years from Earth.

These spectra have a spectral resolution of R=120,000, that means they can resolve two wavelengths only five hundredths of a hydrogen atom’s diameter apart. They cover two large wavelength regions in the visible light simultaneously, and have an unprecedented signal-to-noise ratio. Because the two polarimeters for each of LBT's "eyes" are identical and modular in design, circular and linear polarizations were obtained simultaneously.

The gamma Equ test also included a so-called null spectrum, which is obtained by swapping the observation sequence in the two fibers. Ideally, it would give zero polarization and be independent of wavelength. Any residual polarization would be due to instrumental effects.

"The null spectrum for PEPSI shows an extraordinary low degree of polarization noise caused by the instrument," says its principal investigator, Prof. Dr. Klaus Strassmeier, Research Branch Director at AIP and a professor of astronomy at the University of Potsdam. "Compared with the best spectropolarimeters currently available at other telescopes, it's probably better by a factor of ten." "Eventually, the PEPSI polarimeters will enable stellar magnetic field measurements with extremely high precision," adds PEPSI’s project scientist Dr. Ilya Ilyin.

For Dr. Christian Veillet, LBTO Director, “In the 8-10m class telescope select club, PEPSI was already a unique instrument, thanks to its resolution coupled to two 8.4-m mirrors simultaneously available. The addition of a polarimeter on each of LBT’s eyes gives LBTO yet another unique capability. It comes as a precious complement to interferometry, which gives LBT's two eyes the imaging resolution of a 23-m telescope."

The PEPSI instrument is available to all LBT partners including the German astronomical community.

More information about PEPSI:
pepsi.aip.de

More information about LBTO:
www.lbto.org
The LBTO blog: https://lbtonews.blogspot.com/2017/10/the-lbt-gets-polarized-first-light-for.htm... 

Science contacts:
Prof. Dr. Klaus G. Strassmeier (Principal Investigator), +49 331-7499 223, kstrassmeier@aip.de
Dr. Ilya Ilyin (project scientist), +49 331-7499 269, ilyin@aip.de

Media contacts:
Katrin Albaum (AIP), +49 331-7499 803, presse@aip.de
Christian Veillet (Large Binocular Telescope Observatory),+1 520-349-4576, cveillet@lbto.org

Images:
Image 1: First polarimetric spectrum from PEPSI. The target is the bright magnetic star gamma Equ. The black line is the PEPSI spectrum and the red line is, for comparison, the HARPS-Pol spectrum. From top to bottom: the magnetic null spectrum enlarged by a factor five, the normalized linear Stokes component U/Ic enlarged by a factor 5, the normalized linear Stokes component Q/Ic enlarged by a factor 5, the normalized circular Stokes component V/Ic, and the normalized integral light I/Ic. Credit: IP/Klaus Strassmeier

Images 2: The two polarimeters SX (left side) and DX (right side) at the two LBT eyes. Credit: IP/Klaus Strassmeier

The LBT is an international collaboration among institutions in the United States, Italy and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona Board of Regents; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, The Leibniz Institute for Astrophysics Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota and University of Virginia.

The key areas of research at the Leibniz Institute for Astrophysics Potsdam (AIP) are cosmic magnetic fields and extragalactic astrophysics. A considerable part of the institute's efforts aim at the development of research technology in the fields of spectroscopy, robotic telescopes, and e-science. The AIP is the successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory of Potsdam founded in 1874. The latter was the world's first observatory to emphasize explicitly the research area of astrophysics. The AIP has been a member of the Leibniz Association since 1992.

Weitere Informationen:

https://www.aip.de/en/news/science/lbt-gets-polarized?set_language=en
https://lbtonews.blogspot.com/2017/10/the-lbt-gets-polarized-first-light-for.htm...
https://pepsi.aip.de
http://www.lbto.org

Dr. Janine Fohlmeister | idw - Informationsdienst Wissenschaft

Further reports about: AIP Astrophysik LBT Observatory magnetic fields oscillation polarization polarized light

More articles from Physics and Astronomy:

nachricht Magnetic field traces gas and dust swirling around supermassive black hole
22.02.2018 | Royal Astronomical Society

nachricht UMass Amherst physicists contribute to dark matter detector success
22.02.2018 | University of Massachusetts at Amherst

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Stiffness matters

22.02.2018 | Life Sciences

Magnetic field traces gas and dust swirling around supermassive black hole

22.02.2018 | Physics and Astronomy

First evidence of surprising ocean warming around Galápagos corals

22.02.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>