Letters of Intent for 2015

LoI 2015-209
Focus Meeting: Addressing Light Pollution/RFI Issues for Protection of Observatory & World Heritage Sites


4 August 2015 to 6 August 2015


Honolulu, Hawaii, United States


Constance Walker (cwalker@noao.edu)

Coordinating division:

Division B Facilities, Technologies and Data Science

Co-Chairs of SOC:

Richard Green (University of Arizona)
Richard Wainscoat (Institute for Astronomy/University of Hawaii)
Malcolm Smith (Cerro Tololo Inter-American Observatory)
Constance E. Walker (National Optical Astronomy Observatory)
See end of Rationale for 3 other SOC chairs. ()

Co-Chairs of LOC:

Bob McLaren (Institute for Astronomy/University of Hawaii)
Jim Crisafulli (Dept. of Business Development and Consumer Affairs, Hawaii)



T1. Faint object observational programs and requirements for dark skies
Dark Energy Survey
NEO Searches
T2. Advances in LED technology and options for spectral management
T3. Issues in Radio-Frequency Site Protection
T4. Progress in protection of specific OIR observing sites
T5. Astronomy, National Parks, and Dark Sky Protection
T6. Extending legal protection in an anti-regulatory environment
T7. Progress and Action Plan for implementing IAU 2009 Resolution B5
T8. Light Pollution’s Effect on Wildlife and Human Health
T9. Light Pollution Issues Related to Population Growth
T10. Communicating Awareness and Action with the Public



Protecting sites (including observatories and World Heritage sites) through slowing the encroachment of light pollution requires engaging IAU members and the public on several levels. These actions include producing long-term sky brightness data inter-comparable with broader public monitoring programs; taking opportunities to educate the public about the value of dark sky preservation; interacting with policy makers and public agencies ranging from localities to the UN to provide legal protection and enforcement for dark sky zones; and interacting with lighting engineers to define dark-sky preserving products and to encourage their deployment. Rapidly advancing technology and associated promotion is leading to deployment of blue-rich artificial light sources that threaten to impact a spectral region previously left relatively untouched. Exploring the nature, possible impact, and potential mitigation of this trend is a timely aspect of this session. With this in mind, the session includes key topics listed above.

Increasing use of artificial light at night has posed a growing threat to the visibility of the night sky, and will soon encroach on the best of the world’s observatory sites. A revolution is now taking place in the rapid acceptance of blue-rich LEDs and other light sources touted as being more energy efficient for outdoor lighting. Many such sources emit a substantial fraction of their energy in the 400-500 nm range, a spectral region previously spared major impact from the 600nm output of common sodium lamps. Some papers will survey the blue-rich sources now being selected for roadways, buildings, and automobiles, and explore the range of spectral energy distributions. This will be contrasted with the progress in Hawai`i County of replacing its streetlights with light-emitting diodes which are equipped to filter out blue light.

The urgency of site protection from blue-rich sources depends on the observational programs that rely on observations at wavelengths less than 500 nm. Selected observational papers will highlight key programs now underway, from stellar population studies to selection of faint galaxy populations in the range of 2<z<3.

Constructive dialogue with lighting engineers engaged in development of new lamps and luminaires holds the prospect of yielding products that could serve astronomy needs for site protection. Exploring specifications that could serve most needs for broad-band and narrow-band lamps can complement specific special needs that may vary by region. For this topic, we will engage the U.S. lighting engineering community (especially in Hawaii) as well as the U.S. National Committee to the CIE and will involve them in planning as well. We are connecting with them via Dr. Richard Wainscoat of the University of Hawaii in Hilo. We will also pursue the cross-linkage between IAU Commission 50 and the CIE (International Commission on Illumination).

It is valuable for those engaged in site protection to hear about successes and general experiences in engaging localities, regional, and national governments. The UNESCO World Heritage program may also have yielded some more results for specific sites by the time of this session. At the same time, other sites may be under particular threat – we note the current issues of lighting in remote areas from oil exploration in South Africa and copper mining in Northern Chile and the Southwestern US.

Site monitoring is critical to quantifying the impact of light pollution. Mature sites such as Kitt Peak and Cerro Tololo now have long time baselines. The last extreme solar minimum has created some of the darkest sky conditions during these time histories. Disentangling the solar cycle variations from the secular trends is critical to making the case for special protection of sites. Representatives from world sites will be encouraged to report on their programs.

Light pollution has effects beyond our right to view a starry night sky. Effects on energy consumption, human health and wildlife have risen to considerable importance in the last few years. Topics like these are of interest to the general public and in terms of the educational outreach we do as observatory or world heritage sites, it would behoove us to include presentations in these areas.

In particular, IAU 2009 Resolution B5 “in defence of the night sky and right to starlight” makes the broad case for protection of the dark night sky for socio-cultural and environmental reasons, as well as for the benefit of research astronomy. Commission 50 is one IAU group moving to implement an action plan to work toward the goals of the Resolution. A moderated discussion in this session would focus on technical solutions and site protection as an element of national and international policy.

The increase in Radio Frequency Interference (RFI) due to the explosive growth of modern telecommunications presents a challenge to radio astronomy observatories. Protection of radio astronomy from RFI encompasses measures from international regulations through the International Telecommunications Union (ITU) to national and local legislative protection. For RFI protection of the next generation radio telescopes like ALMA and the SKA, Radio Quiet Zones (RQZ) have been established via national legislation. Technological measures for RFI mitigation are also in development to minimize the impact of RFI on observations. The full range of these topics will be covered and lessons learned will be explored.

In summary, the topics in this session will draw on the expertise of members from 4 commissions (Commission 50 on Protection of Existing & Potential Observatory Sites, Commission 41 WG Astronomy and World Heritage, Commission 55 Communicating Astronomy with the Public and Commission 46 Astronomy Education & Development) as well as the Office of Astronomy for Development (which has a program on light pollution in 12 African countries) and CIE’s technical committee on roadway lighting. To increase the success of the session, the SOC chairs are drawn from the 4 commissions. The cross pollination of these topical areas during the session will advance our understanding of light pollution and radio interference and remedying their effects.

As a footnote to the SOC members, Anastasios Tzioumis (CSIRO, Australia), Margarita Metaxa (Inst.Arsakeio High School, Greece), and Beatriz Garcia (Observatorio Meteorologico, Argentina) have all accepted to be SOC chairs of this proposed session. Tasso is very involved with radio interference issues; Margarita and Beatriz are very involved with education aspects of light pollution. Malcolm Smith has been active in Astronomy and World Heritage issues, as well as instrumental in penning the B5 resolution in 2009. We have a short list of other members from the different commissions to add later.

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