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Jupiter pole

Editor’s Note: This week we’re at the 231st AAS Meeting in National Harbor, MD. Along with a team of authors from Astrobites, we will be writing updates on selected events at the meeting and posting each day. Follow along here or at astrobites.com. The usual posting schedule for AAS Nova will resume next week.

 

Astrobiters

Astrobites at the undergrad orientation.

Undergrad Reception

We loved getting to chat with so many students at the undergrad orientation and reception on Monday night! It was great to hear about your research projects, your goals for the future, and the things you’re passionate about. Keep on being awesome, remember that we want to hear from you about your research, and let us know if there’s anything we can do to help make your entry and progression through the field of astronomy easier.

Kavli Foundation Lecture: The New Jupiter: Results from the Juno Mission (by Kerry Hensley)

Scott Bolton of the Southwest Research Institute, who serves as the Principal Investigator of NASA’s Juno mission, reflected that before his graduate student days, it seemed like scientists knew everything; results were reported with so much confidence that it seemed that there were no puzzles left to solve. Luckily, that’s far from the case, and the Juno mission is a great example of how new results can topple long-held beliefs and open old topics to new ideas.

Juno sweeps close to Jupiter once every 53 days (the closest approach is known as perijove), careening just a few thousand kilometers above the cloud tops, traveling pole to pole in about two hours, and steadily marching along in longitude to make a map of the planet. The Juno mission has upended established theories about Jupiter’s atmosphere, interior structure, and magnetic field. For example, there is more lightning at Jupiter than anyone anticipated, especially in the northern hemisphere. White clouds — possibly containing ammonia ice — are ubiquitous. The magnetic field has stronger high-order components than expected, and unexpectedly peaks in strength closer to the equator than the poles. The auroral trace of the volcanic moon Io has a split tail. In addition to these individual discoveries, the Juno mission highlights the fact that the four seemingly separate foci of the mission — origins, interior, atmosphere, and magnetosphere — are more interconnected than originally thought.

No Juno presentation could be complete without some gorgeous images from JunoCam. (You can access raw JunoCam images and weigh in on where the camera should look next on the JunoCam website!) After a long approach to Jupiter, the first look at cloud formations on Jupiter’s poles didn’t disappoint; the south pole is dotted with storms arranged in a pentagon, while the north pole sports a stormy octagon. With each successive perijove bringing new and intriguing results, Jupiter surely has more surprises and more theory-toppling in store. Dr. Bolton closed the session with a message for the current crop of young investigators: Keep working on the theories, and don’t believe your professors!

Press Conference: Astronomy from the Stratosphere (by Susanna Kohler)

sofia

SOFIA: not a crazy idea, as it turns out. [NASA/Jim Ross]

The first press conference of the meeting kicked off with a look at some of the latest results from the SOFIA mission. SOFIA’s one of my favorite missions — it’s a big plane flying with a garage-door-sized hole in its side for an infrared telescope to point out. What’s not to love? SOFIA’s flights put it above 99% of the Earth’s water vapor, allowing it to make infrared observations that are impossible to make from the ground.

First up, Kimberly Ennico (NASA Ames) provided a broad overview of SOFIA and its different instruments. SOFIA’s instrumentation is renewable: the team regularly swaps out the instrument that flies on its observing runs. Today’s announcements focused on initial results from the new High-Resolution Airborne Wideband Camera-Plus (HAWC+) instrument and outcomes from the German Receiver for Astronomy at Terahertz Frequencies (GREAT) instrument.

The HAWC+ instrument provides both far-infrared images and polarimetry data, allowing us to explore the structure of galactic magnetic fields. Enrique Lopez Rodriguez (USRA/SOFIA Science Center) presented the first detections of polarized far-infrared emission from external galaxies, which can be used to infer the large-scale structure of the galactic magnetic fields. In particular, he showed contrasting observations from two different galaxies: M82, a starburst galaxy with large magnetized outflows, and NGC 1068, a massive spiral galaxy in which we can see a magnetized spiral arm.

B-G Andersson (SOFIA / USRA) gave an overview of some of the theory behind polarization and how it traces magnetic fields. In one model, radiative alignment torque theory, radiation from stars hits dust grains and causes them to spin up. Once the grains are spinning, they interact with magnetic fields, causing the grains to align. Various recent polarization measurements made with SOFIA/HAWC+ seem to support this theory.

Evidence for this from HAWC+ observations was presented by Fabio Santos (Northwestern University), exploring magnetic fields within galaxies. SOFIA/HAWC+ looked at one of the closest star-forming regions to us, Rho Ophiuchi, and demonstrated that the polarization of the dust grains in this interstellar cloud depends on the density within the cloud. These observations support radiative alignment theory: dust grains on the outskirts of the cloud receive more sunlight and align with magnetic fields more readily, whereas dust grains in the dense cloud interior receive less sunlight and don’t align effectively.

Elizabeth Tarantino (University of Maryland) rounded out the session with a discussion of what SOFIA/GREAT observations have revealed about how gas cools to form clouds and collapse into the stars we observe today. The incredible resolution of the GREAT spectrometer allows us to make measurements of ionized carbon within star-forming regions in other galaxies. From these measurements, we’ve determined that both atomic and molecular gas contributes to cooling of gas — but in different ratios, depending on how actively the region is forming stars. These observations are crucial for understanding the initial stages of star formation.

The press release corresponding to this press conference can be found here.

Plenary Talk: A New Measurement of the Expansion Rate of the Universe, Evidence of New Physics? (by Nora Shipp)

Adam Riess (Johns Hopkins University) is an expert in precisely measuring the expansion of the universe. In fact, he won a Nobel Prize in 2011 for his role in proving that the universe is not only expanding, but also accelerating in its expansion. These days he works on getting as precise a measurement as possible of the expansion rate in the local universe.

Riess

Turnout for Adam Riess’s talk on the expansion of the universe. [Kevin Marvel/AAS]

In today’s plenary, Riess discussed the recent tension between the local and distant measurements of the Hubble parameter, H0. Currently there is a 3.4-sigma discrepancy between measurements by Riess’s group of H0 in the local universe and the value determined by the Planck collaboration from the cosmic microwave background (CMB).

Riess did point out that “it’s not a discovery until 5 sigma,” however 3.4 sigma is certainly interesting, and it sounds like Riess and his group have exciting plans for reducing the errors on their measurements. In fact, Riess said that his goal is to go from 2.4% to 1% errors on the local measurement of H0 within the next 5 years, before the end of HST. An important component of this is incorporating the upcoming proper motion measurements from Gaia.

Although he’s still working on improving his measurement before fully accepting the H0 tension, Riess made some suggestions as to possible physical explanations for the difference between the local value of H0 and the value determined from the CMB. One possibility is a new species of relativistic particle. Riess said his particle physicist colleagues have no trouble inventing new particles without messing with accepted physics. It is also possible that dark matter isn’t completely collisionless. Interactions between dark-matter particles and radiation in the early universe could lead to differences in H0.

This is an exciting time for cosmology — it is unexpected results like this discrepancy that reveal the most exciting new insights into our universe!

You can read more about Riess and his work in an interview by Amber Hornsby.

Seminar for Science Writers: NASA’s Transiting Exoplanet Survey Satellite (TESS) (by Susanna Kohler)

TESS

Artist’s illustration of TESS and a transiting exoplanetary system. [MIT]

In addition to today’s press conferences, the AAS Press Office also hosted a seminar for science writers providing an overview of the upcoming Transiting Exoplanet Survey Satellite (TESS). The seminar kicked off with a broad look at the TESS mission and its science objectives, provided by George Ricker (Massachusetts Institute of Technology). TESS is slated to launch in March of this year, and it will survey an enormous field of nearby, bright stars, searching for small transiting exoplanets.

The mission pipeline doesn’t end when TESS discovers objects of interest. Sara Seager (Massachusetts Institute of Technology) described how these objects then get sent on to the TESS follow-up program, which involves hundreds of people around the world. Seager discussed the expected outcomes from TESS for planet discoveries: we may find 70 or so Earths, hundreds of super-Earths, and thousands of sub-Neptunes. The planets discovered with TESS will be orbiting bright stars, making them excellent candidates for follow-up with observatories like the James Webb Space Telescope to explore their atmospheres.

Padi Boyd (NASA Goddard Space Flight Center) next provided an overview of TESS’s guest investigator program, which just completed peer review of its first proposal cycle, receiving more than 140 proposals from the astronomy community. TESS’s large field of view and high-cadence monitoring lends itself well to a variety of projects, like exploring variability in the stars of the Pleiades, hunting for very early-stage supernovae, and exploring the electromagnetic counterparts to gravitational-wave signals.

Kepler v TESS

Kepler vs. TESS. [TESS/Elisa Quintana]

Wrapping up the session, Elisa Quintana (NASA Goddard Space Flight Center) presented on how TESS meshes with other current and future missions. She opened by explaining that TESS isn’t a Kepler replacement: while Kepler’s planet discoveries are on average ~3,000 light-years away, TESS’s will be much loser, at ~300 light-years away on average. TESS’s field of view covers a solid angle that’s ~20x the size of Kepler’s, and the mission’s goal is specifically to hunt for small planets transiting bright stars, which can then be followed up with other current and future telescopes to learn more about the planets’ properties.

We can look forward to TESS’s launch in the next few months, and we have high hopes for its productivity. Though the nominal mission is only 2 years, Ricker points out that the mission won’t be limited by expendables — it could last several decades in orbit if NASA chooses to continue to fund it! I don’t know about you, but I can’t wait to see what TESS shows us.

Press Conference: An Alphabet Soup of Science from SDSS/APOGEE/BOSS/MaNGA (by Chris Lovell)

Karen Masters (Astrophysical Research Consortium / SDSS-IV), spokesperson for SDSS-IV, kicked off this press conference on the Sloan Digital Sky Survey with an overview of this fourth iteration of the program, along with a sneak peek at some of the exciting science to come from the next iteration, SDSS-V.

At the turn of the 19th century, Henrietta Leavitt was studying Cepheid variable stars, which oscillate in size and luminosity with a regular period. She noted that the period was related to the luminosity of the star, which makes these stars great for measuring distances. Sadly, it was only after her death that Leavitt’s contribution was recognised, so to go some way to rectifying this the AAS has recently decided to name this relation the Leavitt law. Much work has been done on the relation since then, but one aspect that is still poorly constrained is how the composition of the star affects the Leavitt law. Katherine Hartman (Pomona College) and Rachel Beaton (Princeton University) presented observations of Cepheids from the Apache Point Galactic Evolution Experiment (APOGEE) survey, and found that measurements of the composition of these stars give consistent results no matter at what point in the cycle they are observed. This is great because it means that, in future, we only need a single observation of a Cepheid to measure its composition, rather than observations over the whole cycle.

Next up, Robert F. Wilson (University of Virginia) demonstrated the power of combining datasets from different observatories, in this instance measurements of the iron content of stars from the APOGEE instrument combined with exoplanet measurements from the Kepler space telescope. The headline result is that iron-rich stars tend to host planets with shorter periods. A mere 25% increase in the iron content can have a significant effect on the average planetary period, which is intriguing since iron makes up only around 2% of the total mass of your average main-sequence star. The physical mechanism leading to this effect is still uncertain, but Robert proposed a couple of physical explanations: either iron-rich protoplanetary disks lead to formation of planets in tighter orbits, or such systems cause planets to migrate inwards from the outer disk.

Supermassive black holes lie at the center of almost every galaxy and are thought to have a big impact on the properties of their host galaxies. Measuring their masses throughout cosmic time is therefore key, but incredibly difficult. The next talk from Catherine Grier (Pennsylvania State University) presented results from the BOSS spectrograph that uses a technique called reverberation mapping to measure these masses. In short, light from the accreting black hole is seen reflecting off gas in the accretion disk in real time; by studying this light, we can measure its rotation speed, which can be used to infer the mass of the black hole at the center. What’s amazing about this study is that they measure the masses of 849 black holes up to 8 billion years ago — a much bigger sample that probes much further back in time than previous studies.

Sticking to the theme of supermassive black holes, Karen Masters presented evidence for these objects in non-star-forming dwarf galaxies. Her team used results from the MaNGA survey to observe the distribution of both stars and gas in these quiet, low-mass galaxies, and found an intriguing result: they aren’t moving together. This suggests that something is blowing out the gas, a process known as feedback. Fortunately MaNGA provides another piece to the puzzle: the ionization state of the gas. The ionization state is very high in the outflowing gas in these dwarf galaxies, which suggests the feedback is from the central black hole, rather than stars. Massive black holes were not expected to be an important driver of evolution in low-mass galaxies, so these results present a challenge to theory.

All of the these press releases are available on the SDSS website.

Doggett Prize Lecture: Tangible Things of American Astronomy (by Kerry Hensley)

Sara Schechner

Astronomers are enamored with immaterial things: photons, magnetic fields, gravitational waves… But our romance with the ethereal is made possible by the material: telescopes and detectors, spacecraft and spectrometers. The careful treatment demanded by delicate and aging astronomical instruments dating back hundreds of years begs the question: why should we care about documenting and preserving obsolete artifacts from the history of astronomy? Dr. Sara Schechner, the curator of the Collection of Historical Scientific Instruments at Harvard University, answered this question with examples of astronomical paraphernalia throughout history and the effect that astronomical events have on society as a whole.

She noted that outdated instruments and texts can provide insight into how people viewed astronomy in the past. For example, 17th century almanacs and instruments reflected the close kinship of astronomy and religion in that era; astronomy had yet to shed its theological (and sometimes ominous) associations. After the 1684 solar eclipse caused Harvard University’s commencement to be rescheduled (such a bad omen shouldn’t coincide with such an auspicious day), the Harvard president, John Rogers, suddenly died on the day of the eclipse — confirming the astronomical event as a harbinger of doom. By 1759, however, the first predicted return of Halley’s Comet was welcomed with awe.

The women computers of the Harvard College Observatory.

Astronomical materials can also reflect other societal shifts. Glass photographic plates evoke memories of the women “computers” of the Harvard College Observatory. Brilliant yet underpaid, the women of the Harvard Observatory classified hundreds of thousands of stars and developed the spectral typing scheme still in use today. Notably, Henrietta Swan Leavitt formulated Leavitt’s Law — a connection between the period of a Cepheid variable’s pulsation and its luminosity — which was used by Edwin Hubble for his discovery of the expansion of the universe. While the work of the Harvard computers advanced the status of women in astronomy, their success didn’t necessarily advance all women; telescope advertisements catering to male astronomers in the 1960s still featured elegant women caressing telescope barrels, showcasing how astronomical materials can reflect attitudes toward women over time.

Lastly, historical materials can highlight the public’s affinity for astronomy, as well. From amateur astronomers’ efforts to track Earth-orbiting satellites in the 1950s via project Moonwatch to advertisers using the allure of the stars to sell their products, the public’s romance with the stars is well-documented in historical artifacts. Dr. Schechner summarized her talk by saying that learning about our past helps us to live critically in the present; from the public’s reception of science to views toward women, astronomical artifacts are a lens through which we can evaluate societal changes through time.

You can read more about Schechner and her work in an interview by Caroline Huang.

RAS Medal Prize Lectureship: The Effect of Non-Linear Structure on Cosmological Observables (by Caroline Huang)

If you ever take an astronomy course that covers some cosmology, probably one of the first things you’d learn is the cosmological principle — the assumption that matter is distributed isotropically and homogeneously on large scales. A somewhat less general version of this, the Copernican principle, says that we don’t live in a special place in the universe. This is one of the most basic assumptions built into Lambda-CDM, the current leading model that describes the universe.

The truth is, however, that we don’t live in a perfectly isotropic and homogeneous universe, and that these density perturbations may (or may not) have effects on what we observe when we try to study cosmology. For example, gravitational lensing causes objects behind over-densities to look brighter, and objects behind under-densities to look fainter. The Hubble diagram of Type-Ia supernovae assumes that there is no flux bias from gravitational lensing, but theorists have actually gone back and forth on what sort of effects we might see for more than half a century. In his plenary lecture, Professor Nick Kaiser (University of Hawaii) discussed the difficulties of calculating distance as a function of redshift and the various conclusions cosmologists have come to over time regarding the effect of inhomogeneity on observables like Type-Ia supernovae.

One way to think of this problem is to consider that our assumptions about isotropy and homogeneity lead us to conclude that a surface of constant redshift would be a sphere. While this true for something that is perfectly isotropic and homogeneous, when you have even small matter under- and over-densities, this is not the case. Since the universe is almost isotropic and homogeneous, there would only be very small perturbations, but that would cause the surface of constant redshift to look something like the surface of a golf ball: almost spherical, but with wrinkles. Since this could cause us to see a flux bias, it could have an effect on things we measure, like the Hubble constant.

How big are these effects? In the question and answer session, Kaiser said that exactly how large these effects may be is unclear, but that he does think that it’s unlikely that they could explain the difference between the CMB and local Hubble constant measurements.

AAS231

Greetings from the 231st American Astronomical Society meeting in National Harbor, Maryland! This week, AAS Media Fellow Kerry Hensley and I will be joined by a team of talented Astrobites authors — Caroline Huang, Chris Lovell, Nathan Sanders, Nora Shipp, and Benny Tsang — writing updates on selected events at the meeting. We’ll post the summary of the day’s events at the end of each day, and you can follow along here or at astrobites.com. The usual posting schedule for AAS Nova will resume next week.

Want to get a head start before the #AAS231 plenaries begin? Astrobites has been conducting brief interviews with the plenary speakers; you can read about them as they come out over at Astrobites.

We hope to see you around at National Harbor! Here are a few AAS Publishing and Astrobites events that might be of interest to you at the meeting:

Otherwise, drop by and visit AAS, AAS Journals, and Astrobites at the AAS booth in the exhibit hall to learn more about AAS’s new publishing endeavors, pick up some Astrobites swag, or grab a badge pin to represent your AAS journals corridor!

corridors

red supergiants

The American Astronomical Society recently launched a new partnership with IOP to produce a series of ebooks about astronomy and astrophysics. The first book in this line, Astrophysics of Red Supergiants, is authored by Dr. Emily Levesque, assistant professor in the astronomy department at the University of Washington and 2014 winner of the AAS’s Annie Jump Cannon Award, and it’s now available for download with an institutional IOP ebook subscription.

What is Astrophysics of Red Supergiants about, and why might you want to check it out? Dr. Levesque held a webinar last month (which was recorded and can be accessed here) to share more about the content of her new ebook.

What is a Red Supergiant?

A red supergiant occurs when a moderately massive star — perhaps 8–40 solar masses in size — exhausts its hydrogen fuel, evolves off of the main sequence, and transitions to fusing helium within its core. As this occurs, the star’s radius expands, causing its temperature to plummet. Red supergiants are among the coldest and most physically massive stars known.

Why Do We Care About Red Supergiants?

Studying red supergiants can help us to expand our knowledge in a broad range of astrophysical fields. This includes:

  1. Gravitational waves
    The colliding neutron stars that produce gravitational waves likely evolved from red supergiants in binaries. We can therefore use such mergers to learn about red supergiants in the final stages of their lives — as well as use what we know about red supergiants to constrain expected gravitational wave signals.
  2. Supernovae
    Red supergiants are the progenitors that produce some types of supernovae. For this reason, it’s critical that we understand red supergiant evolution so that we can better model the moments leading up to supernova explosion, and better interpret pre-explosion observations of supernovae.
  3. Strange and variable stars
    Many red supergiants show photometric and spectroscopic variability, and we’re still working to understand why. The long list of possible mechanisms that produce variability includes large-scale convection, radial pulsation, sporadic mass loss, changes in the amount and distribution of circumstellar dust, hydrostatic instabilities, and binary companions (which can produce variability via eclipses, mass transfer, wind interactions, etc.). There may also be new physics that we don’t yet know about!
Astrophysics of Red Supergiants

Cover of the new AAS/IOP ebook by Dr. Emily Levesque, Astrophysics of Red Supergiants.

What Can You Learn from Astrophysics of Red Supergiants?

Dr. Levesque’s compact book — only 100 pages long — is written at an advanced graduate-student level and provides a complete primer on the current state of red supergiant astronomy. Chapters in the book include:

  • An Introduction to Red Supergiants
  • Inside a Red Supergiant
  • Physical Properties of Red Supergiants
  • Mass Loss and Dust Production in Red Supergiants
  • Red Supergiants in Binaries
  • Red Supergiants in and beyond the Milky Way
  • Variability in Red Supergiants
  • Red Supergiants and Supernovae
  • The Future of Red Supergiant Research

More Information

Astrophysics of Red Supergiants ebook download: http://iopscience.iop.org/book/978-0-7503-1329-2

Dr. Levesque’s webinar: http://iopscience.iop.org/bookListInfo/author-webinars#Astrophysics%20of%20Red%20Supergiants

If you plan to be at AAS 231, come by to meet Dr. Levesque and celebrate the launch of the new AAS/IOP ebook series with us at the AAS booth (#315) on Wednesday, 10 January at 5:30 p.m. during the poster session!

To learn more about the new AAS/IOP ebook partnership and current and upcoming titles, visit http://iopscience.iop.org/bookListInfo/aas-iop-astronomy#collections.

collaborative authoring

Do you use collaborative document preparation software like Authorea or Overleaf? If so, submitting to AAS journals just got easier. Both systems are now partnered with the American Astronomical Society so that you can directly submit to AAS journals from within Authorea or Overleaf.

What Are Authorea and Overleaf?

Overleaf

Authoring tools like Authorea and Overleaf make jointly preparing a scientific document online easier. [Overleaf]

Authorea and Overleaf are both collaborative, online word processors for technical documents — like scientific articles. For scientists used to writing up their research articles in LaTeX, Authorea and Overleaf provide a way of working in that same, familiar environment while building the paper online simultaneously with multiple collaborators, much like in a Google Doc. This software allows users to write, track changes via version control, host data, provide commentary, and ultimately publish their research.

For more information on how Authorea or Overleaf can be used for scientific manuscript preparation, you can check out this Authorea demo of “The ‘Paper’ of the Future” led by Alyssa Goodman (Harvard University), or read up on Overleaf’s benefits for writing and collaborating.

What Does This Partnership Mean?

The partnership between the AAS and Authorea and Overleaf is intended to make life easier for AAS authors who work with these collaborative authoring tools and wish to submit their article to AAS journals when the manuscript is complete.

For initial submissions to all AAS Journals — The Astronomical Journal, The Astrophysical Journal, The Astrophysical Journal Supplements, The Astrophysical Journal Letters, and Research Notes of the AAS — authors can now submit their LaTeX manuscript and all their figures directly from Authorea or Overleaf to the AAS journal peer-review system when the files are complete. The direct submission from Authorea or Overleaf will also pre-populate the submission forms with some of the metadata, reducing the information that the authors will need to enter by hand when they go to the peer-review system to complete the submission process.

What Else Should You Know?

Authorea

Authorea and Overleaf now allow you to directly submit your manuscript to an AAS journal when it is ready. [Authorea]

The AAS provides LaTeX templates for author use in preparing manuscripts for submission to AAS journals (for more on this, see previous posts about AASTex 6.0 and AASTex 6.1), and these templates are now integrated into Authorea and Overleaf for use preparing manuscripts for AAS journal submission with these tools. You can find the templates for the two services here:
Authorea templates for submission to AAS journals
Overleaf templates for submission to AAS journals

Instructions on how to submit to AAS journals via Authorea can be found here. Any questions about the Overleaf submission process can be directed to the Overleaf contact page.

If you would like more information about the details of submitting to AAS journals from within Authorea or Overleaf, you can visit the AAS journals FAQ on collaborative authoring services here.

RNAAS

Null results — research outcomes that show what doesn’t work, rather than what does — are a crucial part of science. It’s imperative that these results are shared widely, so that researchers can learn from each others’ experiences instead of unnecessarily repeating work.

AAS journals

RNAAS joins the suite of AAS journals. [AAS Publishing]

Unfortunately, null results are often difficult to publish in traditional venues, as they represent the steady march of science in the background rather than exciting new discoveries. And null results aren’t alone — there are a number of other types of scientific research that are of interest to the astronomical community, and yet they cannot easily be shared, archived, or cited.

A Home for Non-Traditional Communications

Enter Research Notes of the American Astronomical Society (RNAAS) — a new and unique journal that just joined the AAS journal family this week. RNAAS provides a means of sharing with the astronomical community work that may not fit into traditional publication outlets. There are many types of submissions that could be appropriate for RNAAS, such as:

  • Null results
  • Timely reports of observations (like the spectrum of a supernova)
  • Brief observations (like the discovery of a single exoplanet or contributions to the monitoring of a variable source)
  • Work in progress or projects of limited scope (like the results of a summer undergraduate research project)

Why Publish a Research Note?

RNAAS is a non-peer-reviewed, non-edited journal that is moderated by one of the AAS journals’ lead editors, Dr. Chris Lintott (University of Oxford). Communications published in RNAAS are brief — they are limited to <1000 words, with space for one table or figure. Research Notes have the benefit of being:

  • Research Note

    An example of a recently submitted Research Note. [AAS Publishing]

    Searchable and citable
    Since Research Notes are indexed by ADS, this ensures that researchers can easily find work that might otherwise have gone unshared. And since Research Notes are assigned a DOI, this means that information from Research Notes can be referenced in future publications.
  • Archived for perpetuity
    Publishing data and results in RNAAS — part of the AAS suite of journals and hosted alongside them by Institute of Physics Publishing — prevents the risk that this less formal information is unintentionally lost to the community as a result of institution changes, outdated websites, etc. (a common problem in academia!).
  • Quick to publish
    Need to notify the community of something in a hurry, and don’t have time to wait for a traditional journal’s publication process? Research Notes are typically available online within three business days of when they are received.
  • Free to access (and to publish!)
    RNAAS is not behind a paywall, so Research Notes can be read by anyone and do not require an institutional or personal subscription to AAS journals to access. What’s more, the AAS is currently suspending charges for all submissions to RNAAS, so publishing a Research Note costs nothing at this time.

Find Out More and Submit

Intrigued? You can go see for yourself what people are submitting to RNAAS.
Convinced? We look forward to receiving your submission to RNAAS!

Citation

Ethan T. Vishniac and Chris Lintott 2017 Res. Notes AAS 1 1. doi:10.3847/2515-5172/aa93da

WWT Fermi LAT 8-year sky map

WWT is now managed by the American Astronomical Society.

Astronomers, have you missed out on WorldWide Telescope (WWT) because you’re not on a Windows computer? Good news: WWT can now be accessed via a web interface, with no dependence on your operating system! Now’s your chance to try it out.

What’s New with WWT?

WWT is a powerful application that allows users to interactively browse the multiwavelength sky as it is seen from Earth and the universe as we would travel within it. Based on feedback from the astronomy community, WWT has now expanded its support so that anyone can use the full features of this application from their web browser.

From the press release:

“WorldWide Telescope has been a mainstay in classrooms, museums, and planetariums since its launch as a Windows application nearly 10 years ago. It is a virtual sky, with terabytes of astronomical image overlays incorporating numerous all-sky surveys across the electromagnetic spectrum. It is also a virtual universe, with high-definition base maps of solar-system planets, 3-D star positions, and SDSS Cosmos galaxies. Beyond data visualization, WWT has a rich contextual narrative layer that allows its users to record their path though the program by creating and sharing “tours.”

Since the AAS took on WWT management, we have been working with the WWT developers to make the program work as well for AAS members as it does for its other 12 million users around the world. Most US astronomers today are not using Windows machines, so we’re excited to announce a new version of WorldWide Telescope for the web, agnostic of your underlying operating system.”

In addition to the web support, other new features have been added to WWT — like enhanced tour-making capabilities, through which you can now link slides and share tours either on- or offline. A number of new data sets have also been added to WWT, including:

  • Minor Planet Center bodies
  • SDSS Cosmos galaxies
  • 3D stellar positions from Hipparcos, with Gaia data on the way
  • Fermi LAT 8-year sky map
  • New Horizons Pluto data
WWT New Horizons Pluto

Screenshot of the WWT web interface displaying the New Horizons Pluto data. [WWT]

Where Can You Get Training?

If you’d like to learn how WWT can assist you in your research or outreach projects, the WWT team is here to help!

Online training sessions on a variety of topics will be offered in the near future; you can express interest by filling out this form. Planning on attending AAS 231? Additional WWT workshops and office hours at the AAS booth will be offered there; more information can be found here.

Resources:

The WWT web interface can be accessed here: http://worldwidetelescope.org/webclient/

For more ideas on how you might use WWT, check out this article: https://aasnova.org/2016/01/13/aas-publishing-what-can-worldwide-telescope-do-for-you/

If you want to stay up to date on new developments with WWT, you can join the general mailing list here: http://eepurl.com/b7T0HH

Terzan 5

Editor’s note: AAS Nova is on vacation until 18 September. Normal posting will resume at that time; in the meantime, we’ll be taking this opportunity to look at a few interesting AAS journal articles that have recently been in the news or drawn attention.

Is Terzan 5, a star cluster that lies ~19,000 light-years away, a true globular cluster born in the Milky Way? Or are we seeing the remains of a dwarf galaxy that was captured by our galaxy? New observations by the Green Bank Telescope in West Virginia have tracked the radio signals of a treasure trove of millisecond pulsars — 36 of them — in the heart of Terzan 5. These signals can be used to trace the density distribution of the cluster, revealing where the matter resides. The observations, detailed in a recent article led by Brian Prager (University of Virginia, Charlottesville) and illustrated in the video below (credited to B. Saxton (NRAO/AUI/NSF); GBO/AUI/NSF; NASA/ESA Hubble), suggest that there is no supermassive black hole in the cluster center. This supports the idea that Terzan 5 is a true globular cluster.

Original article: Brian J. Prager et al 2017 ApJ 845 148. doi:10.3847/1538-4357/aa7ed7
Green Bank Observatory release: Pulsar Jackpot Reveals Globular Cluster’s Inner Structure

failed solar eruption

Editor’s note: AAS Nova is on vacation until 18 September. Normal posting will resume at that time; in the meantime, we’ll be taking this opportunity to look at a few interesting AAS journal articles that have recently been in the news or drawn attention.

Solar eruptions don’t always succeed! The Very High Angular Resolution Ultraviolet Telescope (VAULT2.0) sounding rocket captured an event in 2014 in which a solar filament was shredded by the Sun’s own magnetic forces before it had the chance to result in a coronal mass ejection. These observations, detailed in a recently published paper in ApJ led by Georgios Chintzoglou (Lockheed Martin Solar and Astrophysics Laboratory and UCAR, Boulder), mark the first time we’ve witnessed a filament being torn down by the Sun — allowing us to investigate in detail how and why this happened. Check out the video below (by NASA’s Goddard Space Flight Center/Genna Duberstein) for an overview of the failed eruption and what we learned.

Original article: Georgios Chintzoglou et al 2017 ApJ 843 93. doi:10.3847/1538-4357/aa77b2
NASA feature: NASA Watches the Sun Put a Stop to Its Own Eruption

 

TRAPPIST-1

Editor’s note: AAS Nova is on vacation until 18 September. Normal posting will resume at that time; in the meantime, we’ll be taking this opportunity to look at a few interesting AAS journal articles that have recently been in the news or drawn attention.

If you missed the New York Times publication of this video back in May, it’s definitely worth a watch! The video, created by Matt Russo (CITA, University of Toronto), Dan Tamayo, (University of Toronto Scarborough), and Andrew Santaguida (RVNNERS), provides a musical description — a sonification — of the TRAPPIST-1 exoplanetary system. It was produced in conjunction with a study led by Tamayo that was published in ApJ Letters, exploring the dynamical stability of the TRAPPIST-1 system. The video has since been entered in a science communication competition.

Original paper: Daniel Tamayo et al 2017 ApJL 840 L19. doi:10.3847/2041-8213/aa70ea
New York Times article: The Harmony That Keeps Trappist-1’s 7 Earth-size Worlds From Colliding

And if you want still more coverage of the TRAPPIST-1 system, you may be interested in the recent paper by Adam Burgasser (UC San Diego) and Eric Mamajek (NASA JPL and University of Rochester) exploring the age of the system. Spoiler alert: TRAPPIST-1 and its planets are older than our solar system!

Original paper: Adam J. Burgasser and Eric E. Mamajek 2017 ApJ 845 110. doi:10.3847/1538-4357/aa7fea
Sky & Telescope article: New Age Estimate for TRAPPIST-1

solar eclipse 1854

Editor’s note: AAS Nova is on vacation until 18 September. Normal posting will resume at that time; in the meantime, we’ll be taking this opportunity to look at a few interesting AAS journal articles that have recently been in the news or drawn attention.

Can’t get enough eclipse news? Check out this coverage of the solar eclipse of 1854! Special thanks to Tumblr blogger Nemfrog for digging this out of the archives.

These two sets of photographs both capture the annular solar eclipse that occurred on May 26, 1854, passing close to the U.S./Canada border. The photographs come from articles (linked below) published by two scientists who both watched the eclipse from the state of New York and made extensive measurements of its properties.

Stephen Alexander’s team was able to capture spectacular images demonstrating the annular eclipse during totality. William H.C. Bartlett’s team captured the eclipse during various moments from the point of first contact to that of last contact, making detailed measurements of the Sun’s position in 19 stages throughout this process.

The photographs shown here were taken just three years after the very first successful photograph of a solar eclipse was taken — this was a very new endeavor at the time!

solar eclipse 1854

Daguerrotype published by Stephen Alexander of the total solar eclipse of May 26, 1854. [Alexander 1854]

solar eclipse of 1854 2

Photographs published by William H. C. Bartlett of the total solar eclipse of May 26, 1854. [Bartlett 1854]

Citation

Stephen Alexander 1854 AJ 4 75. doi:10.1086/100439
W. H. C. Bartlett 1854 AJ 4 77. doi:10.1086/100450

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