The 1.6 m Clear Aperture Optical Solar Telescope in Big Bear – The NST

Summary

The first facility-class solar observatory in the US in more than a generation is presently in operation at Big Bear Solar Observatory (BBSO). The telescope is producing diffraction limited images with its 1.6 m clear aperture. This largest aperture solar telescope will provide an essential complement to SDO, Hinode and other satellite data, especially as a probe of the origins of space weather.

Center for Solar-Terrestrial Research (CSTR) -- New Jersey Institute of Technology (NJIT)

Big Bear Solar Observatory (BBSO) of New Jersey Institute of Technology (NJIT) is located high in the San Bernardino Mountains of Southern California. BBSO operates a 1.6 m off-axis solar telescope (the NST) that is world’s largest aperture solar telescope. BBSO is collaborating with NSO in building multi-conjugate adaptive optics hardware and a fully cryogenic near infrared spectrograph for the NST. Both of these instruments will be unique. The NST is also the ideal solar telescope to provide the NASA solar community leading-edge observations to complement NASA observations of the Sun, especially for the low solar atmosphere to provide the most precise, observational lower boundary condition for all studies of the heliosphere and most especially the origin of space weather.

The essential improvement is resolution that is needed in probing the origins of solar dynamics is already available from the NST. In Fig. 1, the NST clearly reveals individual bright points that are the fundament scale of solar magnetism. The small scale turns out to be much more dynamic than imagined.

Fig. 1 Hinode (right) and NST (left) intensity images at the same time and place.

Fig. 2. NST (left) and SDO (right) line-of-sight magnetograms at the same place and a few minutes apart.

Fig.2 shows how sharp NST magnetograms can be. In particular they show small magnetic sources that are otherwise invisible but also highly dynamic. Such information is critical in space weather studies and an essential complement to NASA missions to probe the heliosphere.

The primary mission of the CSTR is to observe and model the solar system environment from the Sun to the Earth. To accomplish its mission, CSTR operates several significant and unique ground-based facilities, including Big Bear Solar Observatory (BBSO), the Owens Valley Solar Array (OVSA) and Automated Geophysical Observatories (AGO) across Antarctica. As well, CSTR is involved as co-investigators or principal investigators in other ground-based and space projects. NJIT is designated as New Jersey’s Science and Technology University. CSTR’s recent postdoctoral associates and graduate students have gone on to make their marks in universities, NASA, national centers and industry. Our successes have made NJIT one of the most significant universities in the U.S. in solar astrophysics and space sciences.

Fig.3. The NST showing its active mirror cell BBSO is located in Big Bear Lake, California in the San Bernardino Mountains of Southern California. The mountain lake is characterized by sustained atmospheric stability, which is essential for BBSO’s primary interests of measuring and understanding solar complex phenomena utilizing our dedicated telescopes and instruments. BBSO new solar telescope is a 1.6 m clear aperture, off-axis telescope, the NST. Roger Angel has pointed out that the NST is also a pathfinder for a new generation of nighttime telescopes like the Giant Magellan Telescope with huge off-axis mirrors

The broad scientific goals of the NST are to (i) make high cadence, high resolution studies of solar flares, (ii) measure the structure and evolution of magnetic fields and flow fields in flaring active regions and (iii) observe the dynamics of kilogauss “flux-tubes”. To accomplish these goals, sophisticated post-focus instrumentation is required.

Early in the three year commissioning phase, Adaptive Optics (AO) and the near- infrared (IRIM) polarimeter were brought on line. TiO and Halpha images from the NST are shown in Figure 4.

Fig. 4.An active region (NOAA 1084) taken on July 2, 2010 in TiO (706 nm) using the1.6 m aperture New Solar Telescope in Big Bear Solar Observatory with realtime correction for atmospheric distortion (adaptive optics). For perspective, the Earth is slightly smaller than the whole sunspot including the dark umbra and the daisy petal-like penumbra. The spot is surrounded by the Sun’s ubiquitous granular field in which the small individual bright points in intergranular lanes are near the diffraction limit of the telescope. Halpha off-band image of the same active region taken a day earlier reveals dynamics in the chromospheric layer overlying the surface region shown in the full sunspot image. Most apparent are long dark streaks across the image that are ~50km/s “jets” arising from the bright magnetic areas immediately outside the main body of the penumbra.

NJIT was founded in 1882 and is currently the Science and Technology University of New Jersey. It is one of two state universities of New Jersey. NJIT’s efforts in astronomy and astrophysics focused in CSTR directed by Phil Goode. The Center was founded in 1997 and has graduated more than twenty PhD’s since its founding. As well, more than ten of our former postdoctoral associates have moved on to tenure/track positions at universities or national centers.