`Alopeke

Nic Scott

Lead Research Scientist

BAERI/NASA ARC

nicscott.org

https://www.gemini.edu/node/21236 Credit: Gemini Observatory/NSF/AURA/Artwork by Joy Pollard

a single star, a circle representing the isoplanatic patch, and the small star shapes are "speckles"

a single star, a circle representing the isoplanatic patch, and the small star shapes are "speckles"

a single star, the smaller circles show worse seeing and smaller isoplanatic patches, each producing "speckles"

a single star, a circle representing the isoplanatic patch, and the small star shapes are "speckles"

a single star, the smaller circles show worse seeing and smaller isoplanatic patches, each producing "speckles"

a binary pair, close enough that they share an isoplanatic patch, producing "speckles" that correspond to their separation & position angle

a single star, a circle representing the isoplanatic patch, and the small star shapes are "speckles"

a single star, the smaller circles show worse seeing and smaller isoplanatic patches, each producing "speckles"

a binary pair, close enough that they share an isoplanatic patch, producing "speckles" that correspond to their separation & position angle

a binary pair, wherein the ratio of their separation to the isoplanatic patch size is such that their "speckles" are not correlated

a single star, a circle representing the isoplanatic patch, and the small star shapes are "speckles"

a single star, the smaller circles show worse seeing and smaller isoplanatic patches, each producing "speckles"

a binary pair, close enough that they share an isoplanatic patch, producing "speckles" that correspond to their separation & position angle

a binary pair, wherein the ratio of their separation to the isoplanatic patch size is such that their "speckles" are not correlated

Kepler-13AB

Labeyrie

1970

Text

a method to obtain diffraction-limited resolution across the full aperture of a large telescope

 long exposure

speckles blur

produce Airy pattern

true images are impossible, only centrosymmetric objects can be reconstructed

speckle pattern is the Fourier transform of telescope pupil

autocorrelation of speckles

(in Fourier space)

modulus

(time-averaged intensity)

In 1980’s bispectral analysis was found to have higher S/N and be less susceptible to systematic error.

Weigelt & Lohmann

1977-1983

double star simulation

bispectrum modulus

triple correlation

record PSF of object

produce synthetic reference star by shifting the speckle pattern

phase is preserved

Speckle masking/triple correlation theory/bispectral analysis, a 3rd order correlation

deconvolve

  true images

Fringe spacing

Fringe orientation

Fringe Depth

Binary separation

Binary position angle

Binary magnitude difference

1s

40s

20min

An aside on Lucky Imaging

  • reaches higher resolution than typical seeing
  • does not utilize Fourier analysis
  • not capable of reaching the diffraction limit
  • requires a very large number of  images

http://inspirehep.net/record/823349/plots

Fried

1978

record a large series of images

discard instances of poor resolution

combine the remainder through shift-and-add techniques

Can reach high angular resolution and is often confused with speckle imaging.

Science Programs

58 total proposals

138.3 total nights

(NOAO 2016A to 2019B)

  • Constrain NEA diameters. Image SS objects
  • Determine multiplicity of nearby K and M-dwarfs, does it vary across spectral type?
  • Imaging of brown dwarfs and distant large planets, particularly around M dwarfs
  • Investigate differences in planetary system architectures between multiple vs not (known) multiple host stars
  • Examine long-term RV trends/determine binarity of RV planet hosts.  
  • K2, TESS follow-up
  • Provide an unbiased sample for TESS, so statistical determinations of planet occurrence rates can be made
  • Occultations, transit photometry, pulsar time scales, observe pulsating WDs at high cadence

Some proposals:

DSSI/NESSI/`Alopeke/Zorro

Speckle

  • 10mas/pxl
  • mag limit ~17
  • contrast limit ~8

Wide Field

  • 73mas/pxl

Speckle

  • 18mas/pxl
  • mag limit ~14
  • contrast limit ~6

Wide Field

  • 81mas/pxl

0.011'' @u

0.026'' @832nm

0.025'' @u

0.060'' @832nm

6.7''

60''

19''

56''

Seeing-limited

Reconstructed

42''

Two-color wide-field speckle reconstruction

from NESSI

  • 0.25'' resolution from 500 frames (20s)
  • compromise b/t angres and contrast
  • Seeing ~ 0.85''

3-4x improvement over native seeing

Text

Text

M13

  • astrometry of clusters
  • very early results and little calibration or modelling over the FoV

Reconstructed

Seeing-limited

Abs astrometry residuals

~6-7 mas

4.2 mas

Further improvement possible to obtain ~0.02 pix (~0.4mas)

  • optics, dither, deeper obs

0.05 mag accuracy on aperture photometry

FWHM ~7pix (0.57'')

FWHM ~4pix (0.3'')

Online User Manual

Connecting

  • Power: open browser & go to boot bar IP
    • 4 plugs: pc, red camera, blue camera, power strip (zabers+filter wheels)
  • VNC: find Alopeke/Zorro in gemini VNC gui 

Starting Up

  • After PC starts
    1. power cycle the filter wheels (boot bar:power strip)
    2. Run permissions script
    3. Start Speckle Control Software
  • Once software is up
    1. Home the Zabers
    2. Speckle focus: extend
    3. Pickoff: extend
    4. Mode: Speckle

Speckle settings

  • Exp: 0.06s
  • Frames: 1000
  • Frame Transfer: on
  • Check file name 
  • Check data dir
  • Check TCS info
  • Check camera temps
  • Set Filters

On-sky

  1. Run video
  2. ROI: Full
  3. Allow SOS to center & lock
  4. Use mouse in ds9 to check counts & set EM gain for each channel
  5. target is 5k-14k counts
  6. to set gain > 300 check "high gain" DO NOT SATURATE w/ high gain enabled
  7. Abort video, set ROI: 256
  8. check num frames and num sets, filters, comments
  9. click Observe

V <9=3 sequences

V∼9-12=5 sequences

V∼12-14=7-9 sequences

V∼14-16=11-13 sequences

V∼16+ =15-17 sequences

Shutdown

  1. Set EM gain: 0
  2. Stow: pickoff
  3. Stow: Speckle focus
  4. File>Shutdown
  5. Turn off cameras in bootbar
  6. Run "endnight" script in ~/data/$UTdate$ directory
  7. Close VNC

Scripts

Tips

  • Do not forget to re-home the Zabers anytime there's a power cycle
    • Also check this first if anything looks strange, then send them to position
  • When you start the PC, the filter wheels must be power cycled after reboot and the "Device Permissions" script must be run

  • Pulldowns can be "torn out" of gui to stand-alone windows

  • EM gain can be changed while video mode is running. It will update in next series of frames taken

  • To move\adjust the ROI, select it from the buttom menu then in ds9

    go to edit→region and drag the region where you would like

    it to go. Click “OK" in the pop-up box

Additional References 

Brown, R. H. and Twiss, R. Q., Nature 177, 27{29 (Jan. 1956).
Hanbury Brown, R., Davis, J., and Allen, L. R., MNRAS 137, 375 (1967).
Labeyrie, A., A&A 6, 85 (May 1970).
Knox, K. T. and Thompson, B. J., ApJ 193, L45{L48 (Oct. 1974).
Weigelt, G., Scientifc Importance of High Angular Resolution at Infrared and Optical Wavelengths, Ulrich, M. H. and Kjaer, K., eds., 95{114 (1981).
Weigelt, G., Lowell Observatory Bulletin 9, 144{152 (1983).
Weigelt, G. P., Optics Communications 21, 55{59 (Apr. 1977).
Lohmann, A. W., Weigelt, G., and Wirnitzer, B., Appl. Opt. 22, 4028{4037 (Dec. 1983).

Fried, D. L., Journal of the Optical Society of America (1917-1983) 68, 1651–1658 (Dec. 1978).
Horch, E. P., Veillette, D. R., Baena Galle, R., Shah, S. C.,O'Rielly, G. V., and van Altena, W. F., AJ 137, 5057{5067 (June 2009).

Brugière, T., Mayer, F., Fereyre, P., Gu´erin, C., Dominjon, A., and Barbier, R.,  Nuclear Instruments and Methods in Physics Research A 787, 336–339 (July 2015).
Scott, N. J., Howell, S. B., Horch, E. P., and Everett, M. E., PASP 130, 054502 (May 2018).
Hofmann, K.-H. and Weigelt, G., A&A 278, 328-339 (Oct. 1993).
Law, N. M., Mackay, C. D., and Baldwin, J. E.,  A&A 446, 739{745 (Feb. 2006).
Tokovinin, A. and Cantarutti, R., PASP 120, 170 (Feb. 2008).
Andor, CCD, EMCCD and ICCDComparions & Minimizing Clock Induced Charge.
Howell, S. B., Everett, M. E., Sherry, W., Horch, E., and Ciardi, D. R., AJ 142, 19 (July 2011).

Furlan, E., Ciardi, D. R., Everett, M. E., Saylors, M., Teske, J. K., Horch, E. P., Howell, S. B., van Belle, G. T., Hirsch, L. A., Gautier, III, T. N., Adams, E. R., Barrado, D., Cartier, K. M. S., Dressing C. D., Dupree, A. K., Gilliland, R. L., Lillo-Box, J., Lucas, P. W., and Wang, J.,  AJ 153, 71 (Feb. 2017).
Furlan, E. and Howell, S. B., AJ 154, 66 (Aug. 2017).
Teske, J. K., Ciardi, D. R., Howell, S. B., Hirsch, L. A., and Johnson, R. A.,  ArXiv e-prints (Apr. 2018).
Fulton, B. J., Petigura, E. A., Howard, A. W., Isaacson, H., Marcy, G. W., Cargile, P. A., Hebb, L., Weiss, L. M., Johnson, J. A., Morton, T. D.,Sinuko , E., Cross eld, I. J. M., and Hirsch, L. A., AJ 154, 109 (Sept. 2017).
Hirsch, L. A., Ciardi, D. R., Howard, A. W., Everett, M. E., Furlan, E., Saylors, M., Horch, E. P., Howell, S. B., Teske, J., and Marcy, G. W., AJ 153, 117 (Mar. 2017).

Matson, R. A., Howell, S. B., Horch, E. P., Everett, M. E., ArXiv e-prints (May. 2018)

Alopeke training

By Nic Scott

Alopeke training

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