SUNRISE

A balloon-borne solar telescope

The SUNRISE project aims at high-resolution spectro-polarimetric observations of the solar atmosphere on the intrinsic spatial scale of its magnetic structure. The SUNRISE telescope with 1 m aperture and its instruments will provide spectra and images resolving spatial scales down to 35 km on the Sun. The main scientific goal of the mission is to understand the formation of magnetic structures in the solar atmosphere and to study their interaction with the convective plasma flows.

	Science objectives
	MPS contribution
	Related links
	SUNRISE Science Blog (Internet Tagebuch)
	SUNRISE Documentation Database for team-internal usage only.
	SUNRISE Team Address List for team-internal usage only.
	SUNRISE MPS Team Calendar for team-internal usage only.
	SUNRISE home page
	SUNRISE publications by MPS members

Science objectives

Solar magnetism provides one of the great challenges of astrophysics. Its intricate field structure exemplifies cosmic magnetic fields. Its modulation affects the human environment. The universe abounds with objects that are dominated by magnetohydrodynamical and plasma processes, but of all astronomical objects only the Sun offers the possibility to directly and quantitatively investigate these processes with sufficient resolution.

The central aim of the SUNRISE project is to understand the structure and dynamics of the magnetic field in the solar atmosphere. The magnetic field is the source of solar activity, controls the space environment of the Earth and causes the variability of solar irradiance, which may be a significant driver of long-term changes of the terrestrial climate. Interacting with the convective flow field, the magnetic field in the solar photosphere develops intense field concentrations on scales below 100 km, which are crucial for the dynamics and energetics of the whole solar atmosphere. These spatial scales cannot be studied systematically from the ground because of image distortion by turbulence in the lower atmosphere of the Earth. The balloon-borne SUNRISE telescope will, for the first time, provide measurements of the magnetic structure of the solar atmosphere on its intrinsic spatial and temporal scales.

The SUNRISE instrumentation consists of a light-weight solar telescope of 1 m aperture, a spectrograph-polarimeter (SUPOS) for high-precision spectral line measurements in the linearly and circularly polarized light, a filtergraph (SUFI) for high-resolution images in the visible and UV spectral ranges, and a magnetograph (IMaX) providing two-dimensional maps of the complete magnetic field vector and the line-of-sight velocity. The telescope is kept aligned and focussed by an innovative control system based upon a wavefront sensor. Image stabilisation is achieved with a correlation tracker controlling a high-speed steering mirror.

Beginning in 2009, the telescope will be operated during a series of stratospheric balloon flights in order to obtain diffraction-limited image quality and to study the UV spectral region down to 220 nm, which is not accessible from the ground. The facilities of the National Scientific Balloon Facility of NASA and, when available, Ultra Long Duration Balloons will be used. The experience gained by successful balloon flights will put SUNRISE in a good position to become the central element of a future space borne solar observatory.

MPS contribution

MPS is the PI institution and coordinates the SUNRISE project (PI: S.K. Solanki, Project Manager: P. Barthol, Project Engineer: R. Meller, Project Scientist: A. Gandorfer). The SUNRISE main telescope will be built through an industry contract by Kayser-Threde under supervision of MPS. Main parts of the postfocus instrumentation (PFI) will be built at MPS, i.e. the PFI structure, the light distribution and image stabilisation unit (ISLiD), the filtergraph (SUFI), and the spectro-polarimeter (SUPOS). Further hardware contributions of MPS are the instrument control unit (central computer, ICU) and the data storage system.

Related links

SUNRISE is a joint project of

	Max Planck Institute for Solar System Research (MPS), Katlenburg-Lindau
	Kiepenheuer-Institut für Sonnenphysik (KIS), Freiburg
	High Altitude Observatory (HAO), Boulder
	Lockheed-Martin Solar and Astrophysics Laboratory (LMSAL), Palo Alto
	Instituto de Astrofisica de Canarias (IAC), Teneriffa