But for the obscuring effect of interstellar dust, the 10th magnitude star Cygnus OB2 no. 12 would be one of the brightest stars in the night time sky. For more than 60 years, since the earliest studies of this region, investigators have been puzzled by the surprising fact that one of the most luminous stars in our Galaxy happens by chance to lie behind a local concentration of interstellar matter that adds several magnitudes to the visual extinction compared with its siblings in this young star cluster. In a new study published today in Astrophysical Journal, Doug Whittet reassesses the nature of the dust in the line of sight. In particular, this research seeks to test the oft-held assumption that the dust toward Cygnus OB2 no. 12 is prototypical of the “diffuse” interstellar medium where H is predominantly atomic rather than molecular and conditions inhibit the growth of icy mantles on the dust grains.
It is shown that the excess relative to other cluster members occurs in translucent clumps within an extensive network of clouds in the region. Attenuation of the ambient radiation field is sufficient in the cores of the clumps to support the presence of gas-phase molecules, but not to sustain detectable ice formation. In general, the optical properties of dust in the clumps are, indeed, closely similar to those observed in typical diffuse interstellar material, with the notable exception of an unusually low value for the wavelength of maximum polarization. The implied enhancement of polarization by small grains is attributed to increased alignment efficiency in an enhanced magnetic field. This caveat apart, the results of the current work provide reassurance that Cygnus OB2 no. 12 is, indeed, an appropriate choice for studies that target diffuse and translucent phases of the ISM.
The newly published 2015 volume of Annual Reviews of Astronomy & Astrophysics contains two review articles of great relevance to researchers interested in the astrochemistry and astrophysics of interstellar dust.
Observations of the icy universe by Adwin Boogert, Perry Gerakines and Doug Whittet
(link to e-print)
Abstract: Freeze-out of the gas-phase elements onto cold grains in dense interstellar and circumstellar media builds up ice mantles consisting of molecules that are mostly formed in situ (H2O, NH3, CO2, CO, CH3OH, and more). This review summarizes the detected infrared spectroscopic ice features and compares the abundances across Galactic, extragalactic, and Solar System environments. A tremendous amount of information is contained in the ice band profiles. Laboratory experiments play a critical role in the analysis of the observations. Strong evidence is found for distinct ice formation stages, separated by CO freeze-out at high densities. The ice bands have proven to be excellent probes of the thermal history of their environment. The evidence for the long-held idea that processing of ices by energetic photons and cosmic rays produces complex molecules is weak. Recent state-of-the-art observations show promise for much progress in this area with planned infrared facilities.
Interstellar Dust Grain Alignment by B-G Andersson, Alex Lazarian and John Vaillancourt
Abstract: Interstellar polarization at optical-to-infrared wavelengths is known to arise from asymmetric dust grains aligned with the magnetic field. This effect provides a potentially powerful probe of magnetic field structure and strength if the details of the grain alignment can be reliably understood. Theory and observations have recently converged on a quantitative, predictive description of interstellar grain alignment based on radiative processes. The development of a general, analytical model for this radiative alignment torque (RAT) theory has allowed specific, testable predictions for realistic interstellar conditions. We outline the theoretical and observational arguments in favor of RAT alignment, as well as reasons the “classical” paramagnetic alignment mechanism is unlikely to work, except possibly for the very smallest grains. With further detailed characterization of the RAT mechanism, grain alignment and polarimetry promise to not only better constrain the interstellar magnetic field but also provide new information on the dust characteristics.
Rensselaer junior and Physics major Emily Wislowski has been selected by the Universities Space Research Association as the recipient of the 2014 James B. Willett Educational Memorial Scholarship Award. Wislowski was selected from a large number of applicants in a very competitive selection. She received the award today following an RPI Astrophysics Seminar talk on her research on organic molecules in sites of stellar birth. The award was presented by Emily’s research adviser, Doug Whittet. The award honors the late James B. Willet (1940-1998), a noted NASA astrophysicist at the Jet Propulsion Laboratory who also served as the manager of the Galileo mission to Jupiter.
Link to USRA award citation.
The School of Science at RPI, in collaboration with the 2014 Astrobiology Graduate Conference (AbGradCon), hosted the kickoff to Season 3 of the science communications event “FameLab: Exploring Earth and Beyond” on July 29. Graduate students from around the country gathered to learn how to communicate their scientific research in a way that still includes the technical aspects while making it relatable to a general audience. As part of the process participants developed a three-minute, Powerpoint-free presentation of their chosen topic. A preliminary round was held in the morning with a communications workshop following in the afternoon. The field was narrowed down to nine finalists who competed for the title of FameLab champion in front of a public audience at the EMPAC Theater. In the end, Graham Lau, who discussed his near-death research experience with an unstable sulphurous glacier, was named the winner. Breana Hashman, Danny Barringer, and Rensselaer graduate student Charles Martin were selected as wildcards. The winner of the RPI heat, as well as a few select wildcards, will proceed to compete for the national title in Washington, D.C. FameLab is sponsored by NASA in the U.S. in collaboration with the British Council.
Astronaut Rick Mastracchio, who earned his master’s degree in electrical engineering from RPI in 1987, spoke with students at his alma mater via Skype from the International Space Station. Read the full story here.
Mastracchio returns from the ISS on May 12. Astronaut Reid Wiseman, who graduated from Rensselaer in 1997 with a bachelor’s degree in computer and systems engineering, travels to the ISS on May 28. Read the full story here.
Suzanne Baldwin, a renowned geologist and thermochronologist, and a co-investigator of the New York Center for Astrobiology, has been named the inaugural Michael G. and Susan T. Thonis Professor of Earth Sciences in the College of Arts and Sciences at Syracuse University. Through the generosity of Michael Thonis ’72 and his wife, Susan, the newly established professorship will provide additional support for Professor Baldwin’s research program.
In her laboratory, Professor Baldwin investigates the properties minerals and rocks to determine the thermal evolution of the Earth’s lithosphere and planetary materials. Rock samples from around the world and beyond are collected for this research, including from Papua New Guinea, New Zealand and the Moon (Apollo 16 and 17). Her research in astrobiology includes investigation of terrestrial analogs of Martian minerals to test their ability to serve as biomarkers.
“Suzanne epitomizes excellence in science,” says George M. Langford, dean of The College of Arts and Sciences. “Not only does she perform cutting-edge research with a talented team of researchers, she’s also committed to education, and our students benefit from her outstanding accomplishments in the field of petrology. We are thankful to her for paving the way for future scientists, especially aspiring female scientists, and I am pleased to appoint her the inaugural Thonis professor.”
Read the full story here…
The 2014 Astrobiology Graduate Conference (AbGradCon; website http://abgradcon.org/) will be hosted by the New York Center for Astrobiology and held on the RPI campus July 27-31. The organizers are currently holding a competition to design a logo for the meeting. Plans are also in place for two additional events in association with AbGradCon: the fifth annual Astrobiology Research Focus Group (July 25-27, to be held at the Darrin Freshwater Institute on Lake George), and a regional heat of FameLab. Click here to visit the AbGradCon FaceBook group.
The primary role of AbGradCon is to stimulate the future of astrobiology research by bringing together, in a unique setting, graduate students and postdocs within 2 years of finishing their PhD. In so doing, it strives to create and strengthen interdisciplinary and international networks of early-career astrobiologists who will be leaders of the field in the years to come. The conference is unique in that it is an entirely student-led meeting, from the organization to the presentations. The pressures of typical scientific meetings are alleviated to provide an intellectually stimulating yet comfortable environment in which early-career astrobiologists meet, share research and exchange ideas. AbGradCon also helps to foster leadership skills in the next generation of scientists by giving them experience in organizing scientific meetings.
The National Public Media show The Best of our Knowledge, produced by WAMC Northeast Public Radio, has a long association with the New York Center for Astrobiology, airing regular broadcasts on research and education in astrobiology over the past 15 years (see this previous post). The show airing this week is a full-length feature highlighting the 2013 ExxonMobil Bernard Harris Summer Science Camp, in which teams of middle-school students designed missions to search for life on Mars. It includes interviews with students from the winning team and their parents, and with Professor Wayne Roberge representing the NYCA team. The camp is a vital component of the EPO program of the NYCA, and this show does an excellent job of showcasing its significance and the positive impact it had on the students that participated. The show is available on line at:
It’s been a productive year! Here is a brief list of highlights with links.
Personnel recruitment, honors and awards:
Education and Public Outreach:
The Astrobiology community is currently engaged in developing a strategic plan for future research and mission planning, the outcome of which will be a new Astrobiology Roadmap. As part of this activity, Doug Whittet (RPI/NYCA), Jamie Elsila (NASA Goddard) and Greg Springsteen (Furman University) co-presented a webinar on September 26, 2013, discussing the ideas in a white paper they coauthored on the Origin of Organic Monomers. The presentation is now available as a YouTube video (click here for the link).
Daniel Angerhausen, a postdoc in the Department of Physics, Applied Physics, and Astronomy, has fulfilled his quest to conduct research aboard NASA’s flying observatory, SOFIA (the Stratospheric Observatory for Infrared Astronomy). From anticipation in April, to disappointment in May, he finally got to fly SOFIA on September 26. “So I spent the night at 42,000 feet on a billion dollar NASA aircraft observing an alien world 63 light-years away. How was your night?” tweeted Daniel the morning after his first flight. Click here for the full story.
An excellent article published today in the New York Times gives an in-depth discussion of the new results of the Curiosity Mission, including the discovery of significant water in the surface minerals, reported in Science and described in a previous post. Click here to link to the New York Times article.