# Cool Stars 20 Proposal

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# Host Institution

: Harvard-Smithsonian Center for Astrophysics

## Other local Institutions who have agreed to help with the organization

: Boston University
Massachusetts Institute of Technology

: Scott Wolk (SOC chair; Staff Scientist; Chandra X-ray Center/SAO/CfA).

## Other local scientists who have agreed to help with the organization

:

• Nancy Brickhouse (Senior Science Advisor for the Harvard-Smithsonian Center for Astrophysics);

• Andrea Dupree (Former AAS President, Former Associate Director, CfA Solar and Stellar Physics Division);

• Dimitar Sasselov (Director, Harvard Origins of Life Initiative - CfA)

• Josh Winn (Assistant Professor MIT)

• Catherine C. Espaillat (Assistant Professor Boston University )

• David Huenemoerder (MIT)

• Moritz Günther (MIT)

• Philip Muirhead (Assistant Professor Boston University )

• Edward DeLuca (Senior Astrophysicst SAO/CfA)

• Charlie Conroy (Assistant Professor Harvard University - CfA)

Scott J. Wolk

Chandra X-Ray Center Harvard-Smithsonian Center for Astrophysics 60 Garden St. MS-70 Cambridge, MA 02138

swolk@cfa.harvard.edu 617-496-7766 (vox) 617-495-7356 (fax)

July 2018

# Proposed Site of Meeting:

Boston/Cambridge MA.

# Meeting/Facility considerations (Hotel, conference center, observatory?)

We are exploring two options on hosting the meeting.

## One option is a large conference hotel

The most probable option would be to hold the meeting at the Cambridge Marriot the site of Cool Stars 10. Negotiations are not complete The dates of the meeting for purposes of the planning are July 24-28 (Monday through Friday). However the last two weeks of June are also possible.

As this was the site of Cool Stars 10, we have considerable experience in organizing meetings at these facilities and we would be able to draft LOC members who have been involved in some of those meetings. The complex includes a large $$\sim$$ 10,000 ft$$^2$$ Ballroom space. This would be split between Meeting space and poster space. Standard WiFi and audio and video systems are available at a cost which is scalable by the size of the meeting. They have multiple ballrooms any combination of which can serve as the poster room and multiple smaller, class size rooms. The hotel provides complimentary Wi-Fi access in public spaces. Guest rooms include: Complimentary unlimited wireless Internet access using either a laptop or hand held device that is Wi-Fi 802.11a/b/g compatible and T3 hard lines. The hotel is linked to the Airport via the T (metro) which stops there. Probable cost for a meeting at this location is around $600. We are working with the AAS to see if we can cost cap at$650. (see below).

## Hosting the meeting on the Boston University Campus

However as noted below room costs can be high in Boston. The second option we are exploring will be to host the meeting at BU in the George Sherman Union. This is a facility fairly similar to The conference center used in Flagstaff.

The main hall is a 12,000 square foot ballroom which can be used for a large plenary with a balcony that overlooks and is connected to the ballroom). This great, flexible space can be split into 1/3 and 2/3 to provide space for additional breakouts/functions. There is an large lounge with an outdoor terrace/patio for the posters and breaks. This location is not as ideal as the Cambridge location, but could be significantly less expensive. Most probable dates for this configuration are July 30-August 3. Probably costs at this location run about 60% those of a hotel based meeting.

## Summer in New England

The Summer season lasts from mid-June to the beginning of September. This is a tremendously popular time for both international and domestic travelers to visit Massachusetts. During the warm days of Summer travelers and natives alike flock to New England’s popular lakes, beaches, and coast. The Atlantic Ocean will be at its warmest late in the summer, around 75 degrees. Back in Boston the city undergoes a sea change. Boston empties as its large student population departs for Summer vacation, and the city comes alive with innumerable outdoor concerts and festivals. Music lovers take advantage of the balmy 80-90 degree days to sit and be serenaded at these concerts in the city’s parks. Bike Tours and whale watches are also popular.

Possible side trips which were part of Cool Stars 10 include: A Res Sox game at historic Fenway park, a whale watch, a cruise to a nearby island with a lobster and clam bake, and a pub crawl.

For visitors staying a little longer, the entertainment options are more varied. The Berkshires, Massachusetts’ westernmost region, play host to world renown Summer theater and serve as the seasonal home of the Boston Symphony. In the north the White and Green Mountain National Forests offer exception hiking, biking, boating and camping opportunities. In the hills the temperature at night can dip into the 50s and 60s.

# Transportation considerations (Airports, public transportation, travel time, ease of access etc.)

Boston is easily accessible to the outside world, primarily via Logan airport (BOS) but also via several smaller airports in the greater Boston area (e.g. Providence, RI, Manchester, NH). The public transportation system in Boston is extensive, safe and reliable, many visitors view having a rental car as a liability. Public transportation includes Water taxi and the “T” (Metro) which has both train and bus service. Taxi fare is typically less than $40 to the Boston Cambridge area. # Rooming/Hotel considerations (Range of facilities/cost): ## If we host the meeting at a major hotel Unfortuantely, the greater Boston area has a very high level of hotel pricing. The discount rate for the Marriott is about$250 U.S with 50 rooms available for US Government employees at $198. here is a second hotel, a Marriott, attached to the convention center. Boston features many 4 and 5 star hotels. There are also over 25 bed and breakfast style accommodations such as The Newbury Guest House and Harbor Side Inn with up to 30 rooms for between$150-$200 per night. Given high average cost of accommodation, we will include a “find a room mate” forum on the CS20 website to help participants who are willing to share to reduce their cost, similar to what is done for AAS conferences. In addition we expect to be able to reserve a small block of rooms (25-50) at MIT these would be $$< \100$$ per night. If the meeting is at the Marriott Cambridge those will be very convenient. The Cambridge location has several advantages including live music during the summer easy access to the Science Museum and the MIT campus, ## If we host the meeting at BU, primary housing cost are very low: 2018 Overnight Accommodations rates: Air Conditioned, Suite-Style:$85 per person per night, single occupancy bedroom, shared bathroom (4 persons per suite) Beds come made with linen and bath towels, and basic amenities.

In addition, breakfast will be available in the dinning Hall at   $8.35 per person per day 2016 Overnight Parking Pass:$20 per car per night and $15 per day. We understand some people do not like dorm living no matter how new or air conditioned. So we would arrange for a block of 50-100 rooms at the Cambridge Hyatt directly across the river from BU. These would run about$250 a night a include a shuttle bus to the meeting site. The BU campus is a couple of miles from the Boston common and a mile from Back Bay, but has excellent access to Landssown Street night life including the House of Blues, Taquilia Rain and Lucky Strike (high end bowling and pool).

# Potential Sources of financial support in addition to registration fees:

While we have no firm commitments at this point, we have had positive discussions with Belinda Wilkes, Director of the CXC. The CXC typically hosts a summer workshop and those funds and personnel could be direct toward this meeting. We have also approached Northrupt Grumman Space Technology (NGST). NGST supports Chandra flight operations and were receptive to supporting this meeting. Other potential sources include the CfA as a whole. Accross Cambridge, two other possible sources of local support include the MIT Kavli Institute for Astrophysics and Space Research. The university of Massachusetts at Lowell has also expressed interest in supporting this meeting.

## Contracting and Risk Control

One of the difficulties of planning meetings like this is the negotiations with the service providers. When done poorly this can lead to cost escalation. Further since we are coordinating among Several local hosts, there is a certain assumption of risk (i.e. due to poor attendance) absorbed by one institution relative to the other. To help alleviate this problem we are in discussion with the AAS Topical Conference Series (AASTCS) for assistance in production. These would include processing registration and registration fees, dealing with grants to the conference and subsequent travel awards, and paying invoices. If approved the AAS would act as contracting agent and guarantee a fixed registration fee (expected to be$$<$$ $650) in exchange for a fee of about$40 per attendee.

In addition, as with previous US-based CSW meetings, we will contact NSF for support. The remainder of the financial support will come, as usual, from registration fees. J. Stauffer has offered to share his own records of the finances for CS10 and CS14 and a summary of the CSW12, finances from T. Ayres from which to begin planning.

# Why Should CS20 be held here?

The greater Boston area is home to several world-class astronomical research centers, which all have made significant contributions to our current understanding of cool stars. Three of them apply jointly to host CS20 in the Boston/Cambridge area.

The largest of these three institution is the Harvard-Smithsonian Center for Astrophysics, itself a collaboration of two historic institutions: The Harvard College Observatory was founded in 1839 at a time when few such facilities existed in the United States. Its 38-cm retractor rivaled the largest in the world at its opening in 1847 and is still available for use on clear nights. Under the directorship of Edward Charles Pickering from 1877 to 1919, the observatory became the world’s major producer of stellar spectra and magnitudes, and applied mass-production methods to the analysis of data leading to the creation of the SAO catalog and the present day spectral classification system.

The Smithsonian Astrophysical Observatory was established in 1890 in Washington, D.C., for the specific study of the Sun’s radiation. Later SAO focused on the study of the amount and character of, and variations in, the Sun’s energy. For the next four decades convinced that a link of predictive value existed between solar variations and the Earth’s weather, SAO maintained a solar-monitoring program that eventually included observing stations in Chile, California, and the Sinai Peninsula, Egypt. In 1955, under a thoroughly modern director, Fred Whipple, the Smithsonian Astrophysical Observatory relocated to Harvard University to affiliate with the Harvard College Observatory. The CfA, has led pioneering research in stellar astrophysics including development of the Skylab X-ray mirrors to study the Sun and Einstein. It was results from Einstein, as well as IUE, which led to the first Cool Stars Workshop in 1980. Cool Stars 2 and 3 were also held in Cambridge in the early 1980’s.

CfA hosts the Harvard Origins of Life initiative as well as a uniquely broad array of Astrophysics and Heliophysics research groups: IRAC, IRIS, AIA (Solar Dynamics Observatory), XRT (Hinode), HRC (Chandra), Megacam/Hectospect/Hectoshelle (MMT) instrument teams and is the home of the SMA and the Chandra X-ray Center.

MIT is host to the Kavli Institute for Astrophysics and Space Research (MKI). The MKI invests considerable resources in the development of space-telescope hardware, including detectors, gratings and other systems. MKI is responsible for the ACIS and HETG on Chandra; MKI also leads the construction of TESS, a NASA small explorer mission, which will perform an all sky transit survey and find many planets around cool stars. TESS will launch between CS19 and CS20 and first results might be available at CS20, which makes it timely to host CS20 in the Cambridge/Boston area. TESS is one example where CfA and MIT are closely collaborating. Participants include Latham, Sasselov, Torres, Bakos, Holman (CfA) as well as Ricker (PI), Seager, Winn, Elliot, Hewitt, and Vanderspek (MIT).

Other areas relevant for Cool Stars are the Magellan telescopes where CfA and MIT own a share and contribute instrumentation as well as the Kepler mission, which has been a cornerstone of cool star and planetary systems research in both institutions.

In addition to the Kavli Institute, MIT also has a very active planeteray science department. While this is not the traditional audience of the Cool Stars, an increasing number of exoplanets is physically characterized through observtations and, in the same way as we interpret stars with the sun in mind, exoplanet researchers will need closer contact with those groups that aim to understand the bodies on our own solar system through remote sensing and experiments physically located on comets or planets.

The third institution is Boston University. Astronomy was the first science to be taught systematically at Boston University (BU). Professor Judson Boardman Coit was hired as an Assistant Professor of Astronomy in 1882. Since BU did not yet have any telescopes, Coit led his students to Boston Common Observe stars. Early scientific work at BU included observations of sunspots. Much later, in 1957, a young astronomer from England, Gerald S. Hawkins, who had been working at the Smithsonian Astrophysical Observatory next to the Harvard Observatory in Cambridge, was hired by the Physics Department of Boston University to teach astronomy. In 1966, Hawkins, who had already become a full professor, published his famous book, Stonehenge Decoded, which brought him great publicity. He used this publicity to convince the University to establish a new Department of Astronomy, which formally became an independent department in the fall of 1966. Hawkins was named the first Chairman of the Astronomy Department, which had two other full-time members. Today, the BU Department of Astronomy consists of 15 full-time faculty, covering a wide range of research topics, including space physics, planetary science, star and planet formation, extrasolar planets, extragalactic studies and cosmology.

The Discovery Channel Telescope (the “DCT”) is a new, state-of-the art, 4.3-meter optical and near-infrared telescope located in Happy Jack, Arizona, approximately 40 miles southwest of Flagstaff. The DCT is owned and operated by Lowell Observatory with support from Discovery Communications, Inc., Boston University, the University of Maryland, the University of Toledo and Northern Arizona University. In October of 2011, BU and Lowell Observatory signed a formal agreement that grants BU astronomers access to the DCT in perpetuity. In addition to carrying out forefront astronomical science with the DCT, members of the BU Department of Astronomy in the College of Arts and Sciences will be working with their colleagues in the School of Education and the College of Communications to build a strong program of education and public outreach, centered on modern astronomical science and the DCT.

# Science Themes

The 20th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun (Cool Stars 20) is planned to take place in summer 2018.

This is the planned launch of JWST and a year that marks the start of our next expedition into the frontiers of astronomy. Between CS19 and CS20 we will also see a great move forward with the expected launched of TESS – the first all sky planet finder and CHEOPS – the first space mission intended to follow up and characterize super-Earths. Cool Stars 20 will serve as a perfect platform for refining the final details for proposals using these missions.

More important than mission that will be new in two years, are the missions and facilities that are new now and will be at their peak in terms of vitality energy and new discoveries. These include ALMA, JVLA, Astro-H Sofia and Gaia.

## List of possible science themes (unsorted)

### Bring the sun back into “Cool Stars, stellar systems and the sun”

In recent years, the communities of cool stars and solar physics have more and more diverged, as the stellar astronomers have concentrated on the great zoo of exoplanets, while solar astronomers have increasingly detailed spectral, spatial and temporal resolution in their observations that has simply no comparison in stellar astrophysics. Given the strong solar research groups at the CfA, a workshop in Cambrdige is uniquely suited to set an agenda with a strong solar component, that will attract solar astronomers to be presenters and workshop participants. Despite the different fashions in both fields, the old guiding principle that we understand cool stars from looking at the solar example in detail, and that we understand the sun by comparing to a more complex sample with e.g. different ages (sun in time), masses, or abundances is true. Even people talking about potential Star-planet-interaction always come back to the solar example. The last few CS workshops had invited solar talks, but very few participants from the solar community, thus there were no solar posters, no contributed solar talks and no discussion in the corridors with solar physics experts. Thus, I advocate for a 1-day theme focused entirely on the sun, strong enough in solar speakers and rooted in the CfA solar groups to draw attendance from the solar community worldwide.

### Mechanisms of Instability

Theory and observations of magnetic storage and release. The combination of 3D MHD modeling and a large array of multi-wavelength observations allows for direct testing of the storage and release mechanism in one start. This session will explore specific examples from well observed solar events and the implications of our new understanding for stars and stellar systems. [suggested by Ed DeLuca]

### The importance of the invisible

The importance of the invisible: A great advancement has been achieved in recent years in stellar observations (e.g, ZDI maps of the stellar magnetic field). However, these observation are still limited by a rather low-resolution. This session will discuss the implications and limitations of these observations to provide a physical insight of stellar systems. For example, we will discuss how crucial is the small scale magnetic field and the details about the stellar wind in defining the evolution of the stellar parameters.

### Modeling stellar spectra in the era of massive surveys.

The measurement of stellar parameters from spectra underpins much of our knowledge in topics ranging from the build up of the Milky Way to the mixing processes in the outer regions of stars. This field is undergoing rapid changes thanks both to a rapid growth in observational datasets (APOGEE, GALAH, Gaia-ESO, etc) and an explosion of new tools for analyzing such large and rich datasets. This session will bring together communities working on detailed (3D, NLTE) spectroscopic models, classic 1D models and data-driven models (e.g., the Cannon) and will explore the advantages and limitations of these techniques in the context of modern spectroscopic surveys.

### Star Formation

The last decade or more of observational star formation has been characterized by wide-field, multi-wavelength surveys. These studies have provided a rich database across star formation, from the collapse of filaments to the identification of transitional discs. For the first time GAIA will be a major contributor to our understanding of the structure of young cluster. While GAIA will change our understanding of the structure of young clusters and how they relate to the structure of the near by galaxy, High resolution observations, including those from ALMA have given stunning visual confirmation of structures hinted at with spectra and photometry. One the other hand new remarkable computer simulation predict that will have even more to find when JWST comes on line, soon after the conclusion of this meeting.

### Dynamically Changing Young Stars and their planetary systems

The K2 mission is giving us a new understanding of dynamical changes across several young clusters and millions of young stars. So far we am aware of 2 newly discovered planets around young stars in the Hyades and there is very active work on the Pleadies which will only be touched on in the Upsulla