High Altitude Observatory (HAO) – National Center for Atmospheric Research (NCAR) The National Center for Atmospheric Research is operated by the University Corporation for Atmospheric Research under sponsorship of the National Science Foundation. An Equal Opportunity/Affirmative Action Employer. The Coronal Solar Magnetism Observatory (COSMO)

Steven Tomczyk COSMO 23 April 2013 Motivation Our Vulnerability to Space Weather is Increasing  Manned Space Flight  Power Grids  Communications  GPS Navigation

Steven Tomczyk COSMO 23 April 2013 In response to society’s need to reduce our vulnerability to Space Weather, the goals of COSMO are to:  Understand processes that lead to solar eruptions  Support development of predictive capability  Monitor real-time eruptive events  Estimate event geo-effectiveness COSMO Goals

Steven Tomczyk COSMO 23 April 2013 Requirements Solar activity is Magnetically Driven Progress requires measurement of: Strength and direction of magnetic fields in the Solar Corona, Chromosphere and Photosphere Plasma properties Velocity, Temperature, Density Need Systems Approach LASCO

Steven Tomczyk COSMO 23 April 2013 COSMO is a proposed facility dedicated to studying solar magnetic fields and their role in driving solar activity such as coronal mass ejections Synoptically. It comprises:  1.5 m Aperture Coronagraph (Corona)  Disk Imager / Polarimeter - ChroMag (Chromosphere/Photosphere)  K-coronagraph (CME) 1.5-m coronagraph pictured here COSMO

Steven Tomczyk COSMO 23 April 2013 COSMO Facility Concept Large coronagraph and solar pointed spar will reside in adjacent domes. Spar can carry suite of instruments.

Steven Tomczyk COSMO 23 April 2013 K-Coronagraph  Measures coronal structure and evolution  Observes Coronal Mass Ejections in real-time  Observes shocks which produce energetic particles Fully funded ($2.2M, NSF special), construction nearly complete, deployment to MLSO late Summer

Steven Tomczyk COSMO 23 April 2013 Chromosphere and Prominence Magnetometer (ChroMag) ChroMag will make complete-Stokes observations of the entire solar disk at high temporal cadence in many spectral lines ( nm) that can be used to accurately infer the magnetic field and other plasma parameters from the photosphere through the chromosphere.

Steven Tomczyk COSMO 23 April 2013 ChroMag - Tunable Filter

Steven Tomczyk COSMO 23 April m refractive coronagraph 1º field-of-view Low scattered light Synoptic operation Will obtain measurements of Coronal B with 1 Gauss precision in 10 minutes, 5 arcsecond spatial resolution COSMO Large Coronagraph Would be largest refractive telescope in the world, $20M

Steven Tomczyk COSMO 23 April 2013 COSMO LC Design Drivers  Large aperture –Need to collect photons (V/I ~ / Gauss)  Low scattered light –Lens better than mirror (microroughness and dust)  High efficiency - no reflections –ATST 10, EST 14 reflections before coude instruments  Symmetrical on-axis optical system - Makes polarimetry easier  Large Field-of-View - Coronal structures are large - aberrations are easier to control with a lens than a mirror  Pressurized Dome Design –HEPA filtering - maintain cleanliness

Steven Tomczyk COSMO 23 April 2013 LSST will have a 1.6 m diameter lens and a 1.1 m lens! LSST has unique combination of aperture and FOV  Étendue light collecting power = collecting area x solid angle FOV = 319 m 2 deg 2 Large Synoptic Survey Telescope

Steven Tomczyk COSMO 23 April 2013 The COSMO coronagraph will have a light gathering power (étendue) that exceeds that of the ATST by a factor of 15. COSMO is Highly Complementary Most existing and planned solar telescopes have small FOV, will observe at high spatial resolution and are not synoptic. Sun ATST FOV COSMO FOV Sun Offset Mode

Steven Tomczyk COSMO 23 April 2013 COSMO LC Status  COSMO Large Coronagraph Conceptual Design, Feasibility Study Complete  COSMO Now an International Project –US/China Collaboration on Design Development  Preliminary Design Review – Feb 2014  Submit Proposals to Chinese and US Agencies for Construction of 2 Large Coronagraphs  COSMO Endorsed by 2012 Heliophysics Decadal Survey