Transit of Venus ObservationsFrom National Solar Observatory

National Solar Observatory Facilities

Dunn Solar TelescopeSunspot, New Mexico, USAD = 76cm, λ=380-1700 nm

McMath-Pierce TelescopeKitt Peak, Arizona, USA

D = 160 cm, λ=1000-5000 nm

Transit Conditions – Sacramento Peak

Interferometric BIdimensional Spectrometer (IBIS)

Dual Fabry-Perot Imaging SpectrometerP.I. - Fabio Cavallini (INAF/Arcetri)

Facility Instrument at the NSO/Dunn Solar Telescope since 2005

Publication List: http://tinyurl.com/ibis-pubs

Instrument Design: Cavallini, F., 2006, Solar Phys., 236, 415.Spectral Profile: Reardon, K., Cavallini, F., 2008, A & A, 481, 897.MTF: Righini, A., Cavallini, F., Reardon, K., 2010, A & A, 515, 85.

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Spectral Range: 5400 - 8600 ÅFWHM: 20-45 mÅFOV: 98 x 98 arcsecPixel Size: 0.098 arcsec2/pixelExposure Times: 20-50 msecStrehl Ratio: ~0.95Frame Rate: 8 – 12 frames/secData Rate: ≥ 100 GB/hour (two CCD’s)

Application of post-facto image correction techniques:• Destretching• Speckle Reconstruction• Multi-Object Multi-Frame Blind Deconvolution

Available Filters

Interferometric BIdimensional Spectrometer (IBIS)

Spectral resolution ~200,000 – 260,000

Mercury Transit – 06 November 2006Hα Imaging at Ingress

IBIS/DST

Mercury Transit – 06 November 2006 – IBIS/DST

Imaging Spectroscopy of planetary transit

Na D2 589.0 nm : Scan range = 1.5 Å : Δλ = 0.009 Å0.083 arcsec/pixel

EquivalentWidth

GaussianWidth

GaussianAmplitude

GaussianShift

Mercury Transit – 06 November 2006IBIS/DST Observations of Mercury Exosphere in Na

D2

IBIS Field of View

98 x 98 arcsecMercury

d=10”

98 x 98 arcsecVenusD=60”

IBIS Field of View

• Upper wavelength limit of 8700 Å• Need strongest line to improve SNR• Need to minimize contamination from other solar or

terrestrial spectral lines• Pascal Hedelt simulated Venus CO2 absorption

spectrum from 780 – 4500 nm• Compared simulated spectrum (corrected from

vacuum to air wavelengths!) to solar atlas

Spectral Line Selection for IBIS

Solar + terrestrial atlas spectrumSimulated Cytherian CO2 spectrum

Spectra at 870 nm – Noisy Continuum!

Solar, Terrestrial, Cytherian Spectra – 780 nm

Solar + terrestrial atlas spectrumSimulated Cytherian CO2 spectrum

Solar + terrestrial atlas spectrumSimulated Cytherian CO2 spectrum

IBIS Prefilter Profile

Solar, Terrestrial, Cytherian Spectra

Imaging of AureoleRapid Oscillations of the Solar Atmosphere

(ROSA)http://star.pst.qub.ac.uk/rosa/

Six Andor 1000 x 1000 pixel CCD’s, 30 frames/sec sustained+ image reconstruction techniques

Will use ROSA to take multiwavelength observations (380 – 500 nm) at high cadence during ingress

Look for wavelength dependence of aureole due to scattering processes

Possible addition of 2k x 2k, 50 fps detector

For higher cadence and resolution

Facility Infrared Imaging Spectrograph(FIRS)

Spectral coverage: ~60 Å (λ/250)

Slit length

Slit scanning

Full Stokes Spectropolarimetry

Observe same spectral interval as Hedelt et al. 2011?

McMath-Pierce TelescopeNSO Array Camera (NAC)

1024 x 1024, helium cooled, InSb array

Spectral Range: 1.6 –2.5 μm, 4.67 μmSpectral Resolution: ~50,000 – 70,000Spectral coverage: ~60 Å

Full Stokes Spectropolarimetry

Spectral interval(s) to observe?1.6 and/or 2.2 μm bands