News on Developing Dome A as an International Astronomical Observatory and Progress on the Successful

Traverse (driving in!) by the

Polar Research Institute of China

and the

Chinese Center for Antarctic Astronomy

HOU Teacher Conference, June, 2008

Carl Pennypacker, LBNL, UCB

Lifan WangLifan Wang Texas A and M, USA/ Chinese Center for Antarctic Astronomy, (Director), Nanjing, Texas A and M, USA/ Chinese Center for Antarctic Astronomy, (Director), Nanjing, ChinaChina

Huigen Yang , Huigen Yang , Y. LiPolar Research Institute of ChinaPolar Research Institute of China

Xiangqun Cui, Xiangqun Cui, Xiangyan Yuan Xiangyan Yuan Nanjing Institute of Astronomical Optics and Technology, ChinaNanjing Institute of Astronomical Optics and Technology, China

Jingyao Hu, Zhaoji Jiang, Xu Zhou Jingyao Hu, Zhaoji Jiang, Xu Zhou National Astronomical Observatories of ChinaNational Astronomical Observatories of China

Feng Longlong, Jun Yan, Zhu Zhenxi Feng Longlong, Jun Yan, Zhu Zhenxi Purple Mountain Observatory, China Purple Mountain Observatory, China

Zhaohui Shang Zhaohui Shang Tianjin Normal University, ChinaTianjin Normal University, China

Michael Ashley, Colin Bonner, Jon Everett, Jon Lawrence, Daniel Luong-Van, Suzanne Kenyon, Michael Ashley, Colin Bonner, Jon Everett, Jon Lawrence, Daniel Luong-Van, Suzanne Kenyon, Shane Hengst, John StoreyShane Hengst, John Storey University of New South Wales, AustraliaUniversity of New South Wales, Australia

Anna Moore, Reed Riddle, Tony TravouillonAnna Moore, Reed Riddle, Tony Travouillon California Institute of Technology, USACalifornia Institute of Technology, USA

Craig Kulesa, Chris Walker Craig Kulesa, Chris Walker University of Arizona, USAUniversity of Arizona, USA

Don YorkDon York University of Chicago, USA University of Chicago, USA

  Nick Tothill Nick Tothill University of Exeter, UKUniversity of Exeter, UK

  Bob Tripp Bob Tripp LBNL, USALBNL, USA

Carl PennypackerCarl Pennypacker LBNL, LBNL, Space Sciences Laboratory, USASpace Sciences Laboratory, USA

Collaboration

Outline

1) More rationale on goals of this traverse

2) The Traverse itself

3) Closer inspection of some of the instruments on this traverse.

4) Antarctic Schmidt Telescope Progress

From Lifan’s Talk:

Chinese Center for Antarctic Astronomy

• Dome A Site Survey-Pilot system

- 2007 and 2008 Traverse

- Survey site, determine height of boundary layer, measure seeing

- Do Science with C-STAR -- limiting magnitudes of about 17 (five sigma) in ten

seconds, stack images,

• Antarctic Schmidt Telescopes x 3 (AST3) -- being built now for 2009 traverse!

- 3x 0.5 meter telescopes, 10K x 10K CCD’s,

1”per pixel- ~ 100 good SNe per year, ~1 earth mass

planet a year due to micro lensing, hello-seismology, etc.

• Dome A Survey Telescope (4 - 6 meters ~> 12 - 18 meter in Chile or Mauna Kea) 10,000’s SNe per year, etc.

• Infrared Telescopes -- e.g., very high redshift studies.

(Breath-taking) Timeline of Astronomy Ideas:

June, 2006: Beijing Dome C - Dome A meeting

January 2007: Go decision from Purple Mtn. Observatory, PRIC, NAOC, and Chinese National Academy of Sciences -- Astronomy becomes part of China’s PANDA IPY proposal

November, 2007: Xue Long leaves Shanghai, loaded for traverse (mostly --> on to Freemantle

November 30, 2007: Departs Freemantle, Australia to load PLATO

December 10, 2007: Arrive at Zhongshan Station

December 17: PLATO airlifted to Progress Airfield, tank filled

December 22: Begin Traverse

January 12 : Arrive at Dome A

February 21 , Depart Dome A

Why is the excitement? Example 1

Above A boundary Layer(at Dome C ~ 30 meters) seeing is amazing :

From Poisson Statistics:

Easy arithmetic, for point sources against a sky background, ignoring detector noise:

“Effective” Aperture diameter 1/(seeing disk diamter)

Hence, a 5 meter at Dome A should behave like a 15 meter in Chile.

How to Rise Above the Boundary Layer (if needed) with a translation-only tower ~ 1 micron rotational movement/tilt due to wind -- two studies by Robert Hammerschlag, Netherlands -- based on Dutch Open Telescope Tower on La Palma

With Good Seeing and 4-meter optics, you can do pretty well:

Exposure time -- seconds

Seeing Review:

Ground-based Astronomical Seeing, due to high frequency temperature fluctuations in the path of the beam is often sub-divided into three components, with different physical heights along path:

1) Dome Seeing

2) Boundary Layer seeing

3) “Free atmosphere seeing in Jet Stream

Dome A:

1) No Dome Seeing

2) Boundary layer is low

3) No Jet Stream (polar vortex protects us!)

Characteristics of the Collaboration:

• Support a wide and useful set of astronomy projects, in the price range of $0.001M to $100M

• Do amazing science at lower cost than other sites or orbits (planet finding, deep imaging, infrared imaging, sub-millimeter astronomy, etc.)

• Be a nimble collaboration, that can change goals, science, detectors, many times in response to science and technology opportunities -- aim for Evolution ---> Revolution!

• Do projects with 2 to five year horizons

• Build on the profound commitment of China to Dome A (both for Polar Work and astronomy -- “Dome A is the Best Mountain in China”)

• Good governance, collaboration rules, clear path to joining collaboration

• Very respectful, smart collaboration with good resources, moving incrementally and carefully.

• China’s National Funding agencies, Academy of Science, broader government. In addition, many people of China are supportive of this effort, along with their support for science and technology in general. (hint, hint US Congress)

More Details and Familiar Landmarks

Google Earth View (rotated)

Google Earth View (close-up and rotated)

Progress

Nov 30: Xuelong departs Fremantle

Dec 10: Xuelong arrives Zhongshan

Dec 17: PLATO airlifted to Progress airfield

Dome A Office

Goodbye ‘til Next January

Height of Boundary Layer and Ground Seeing vs. Wind Speeds from Swain/Gallee simulation

Dome A

Courtesy A. Monaghan, Byrd Polar Research Centre

The annual vector mean winds from Polar MM5Dome A

4100 altitude

highest driestcoldest calmest

Wind speed (m/s)

How much better is Dome A than South Pole, Dome C??? PLATO

South Pole Temperature Profile

Temperature

Dome A Temperature Profile

Atmospheric parameters for astronomy Turbulence (SNODAR)

Boundary layer height, distribution and variability Upper atmospheric distribution

Sky emission (Gattini) Auroral spectral intensity and distribution, (visible and infrared) sky

background versus sun/moon elevation

Sky transmission (Pre-HEAT) Transparency and noise in long wave (sub-millimetre) windows

Cloud (Gattini ASC) Cloud cover statistics and distribution

Science (C-STAR) Optical transients: variable stars, transits, micro-lensing, GRB, etc

Site testing

PLATO

PLATO (PLATeau Observatory)PLATO (PLATeau Observatory)

Deployment Jan 2008 via PRIC traverse Completely autonomous and self powered High reliability control system Low bandwidth communications Set up 2 weeks 2 people Dual module design

Instrument moduleInstrument moduleengine moduleengine module

solar panel arraysolar panel array

30 m tilt tower30 m tilt tower

2 m2 m50 m50 m

Concept design Feb 07Concept design Feb 07

PLATO

PLATO (PLATeau Observatory)PLATO (PLATeau Observatory)

Deployment Jan 2008 via PRIC traverse Completely autonomous and self powered High reliability control system Low bandwidth communications Set up 2 weeks 2 people Dual module design

Instrument moduleInstrument moduleengine moduleengine module

solar panel arraysolar panel array

30 m tilt tower30 m tilt tower

2 m2 m

Delivery Nov 07Delivery Nov 07

Provides Power, Shelter, and Control for Antarctic instrumentation Two modules:

Power module Instrument module Separated by 50 meters Modified shipping containers

Shipping containers? Logistics Manufacture Durability

Two modules? Manufacture and testing Diesel contamination Acoustic Water vapour Expansion

PLATO design

MASSMASSportport

Pre-HEATPre-HEAT

Gattini SBCGattini SBC

Nigel portNigel portGattini all-skyGattini all-sky

Iridium antennasIridium antennas

webcamswebcams

Instrument module

sparespareportsports

CSTAR, SNODAR, CSTAR, SNODAR, Sonics located Sonics located externally on snow externally on snow surfacesurface

IM layout

Supervisor nodes (x2)

PC104 computer:

400 MHz Celeron

256MB SDRAM

2 x 4 GB USB flashdisc with read only filesystem on master

Lithium back-up battery

CAN microcontroller:

ATMEL development board

Software wakey-wakey and handshaking

Custom power-switching interface PCB

Iridium L band transceiver

SDB and direct-ssh

Externally located low-temperature antenna

Thermally regulated enclosure

IM Control

SNODAR Surface layer Non-Doppler Acoustic Radar

Designed and built by UNSW / Univ Aukland

high frequency piezo-electric transducer with 1.2 m dish

Measures: high resolution (1 m) Cn2 in boundary layer (5-100/800 m)

Mounting: externally on snow surface

Power: 30 W (internal) + 100 W (external)

Weight: 300 kg (total)

Installation: 1 day

SNODAR

outputSouth Pole 2001…

… Dome C 2003

…and Dome A 2008 ???

Collaborators…Collaborators…

E. Aristidi E. Aristidi Uni. NiceUni. Nice M. AshleyM. Ashley Uni. NSWUni. NSW R. BriguglioR. Briguglio Roma/La SapienzaRoma/La Sapienza M. BussoM. Busso Uni. PerugiaUni. Perugia M. CandidiM. Candidi PNRAPNRA G. CutispotoG. Cutispoto CataniaCatania E. DistefanoE. Distefano CataniaCatania J. EverettJ. Everett Uni. NSWUni. NSW S. KenyonS. Kenyon Uni. NSWUni. NSW J. LawrenceJ. Lawrence Uni. NSW (co-PI)Uni. NSW (co-PI) D, Luong-VanD, Luong-Van Uni. NSWUni. NSW A. PhillipsA. Phillips Uni. NSWUni. NSW B. Le RouxB. Le Roux INAF:ArcetriINAF:Arcetri R. RagazzoniR. Ragazzoni INAF:PerugiaINAF:Perugia L. SabbatiniL. Sabbatini Roma/La SapienzaRoma/La Sapienza P. SalinariP. Salinari INAF:ArcetriINAF:Arcetri J. StoreyJ. Storey Uni. NSWUni. NSW M TaylorM Taylor Uni. NSWUni. NSW G. TostiG. Tosti Uni. PerugiaUni. Perugia T. TravouillonT. Travouillon CaltechCaltech

Gattini-DomeC are part of the IRAIT site testing campaign (Tosti et al)

Dome C

Dome A G. AllenG. Allen Solar MobilitySolar Mobility M. AshleyM. Ashley Uni. NSWUni. NSW T. BeddingT. Bedding Uni SydneyUni Sydney C. BeichmanC. Beichman JPL/MSCJPL/MSC D. CiardiD. Ciardi MSCMSC X. CuiX. Cui Nanjing/NAONanjing/NAO P. EspyP. Espy BASBAS J. EverettJ. Everett Uni. NSWUni. NSW L. FengL. Feng Purple Mountain ObsPurple Mountain Obs J. HuJ. Hu NAO/BeijingNAO/Beijing Z. JiangZ. Jiang NAO/BeijingNAO/Beijing C. KulesaC. Kulesa Steward ObsSteward Obs J. LawrenceJ. Lawrence Uni. NSWUni. NSW Y. LiY. Li PRICPRIC D. Luong-VanD. Luong-Van Uni. NSWUni. NSW W. QinW. Qin PRICPRIC C. PennypackerC. Pennypacker Livermore/BerkeleyLivermore/Berkeley R. RiddleR. Riddle TMT (co-PI)TMT (co-PI) W. SaundersW. Saunders AAOAAO Z. ShangZ. Shang TianjinTianjin D. StelloD. Stello Uni SydneyUni Sydney J. StoreyJ. Storey Uni. NSWUni. NSW B. SunB. Sun PRICPRIC N. SuntzeffN. Suntzeff Texas A&MTexas A&M N. TothillN. Tothill Uni Exeter (co-PI)Uni Exeter (co-PI) T. TravouillonT. Travouillon Caltech (co-PI)Caltech (co-PI) G. van BelleG. van Belle ESOESO K von BraunK von Braun MSCMSC L. WangL. Wang Texas A&MTexas A&M J. YanJ. Yan Purple Mountain ObsPurple Mountain Obs H. YangH. Yang Purple Mountain ObsPurple Mountain Obs X. YuanX. Yuan Nanjing/NAONanjing/NAO Z. ZhenxiZ. Zhenxi Purple Mountain ObsPurple Mountain Obs X. ZhouX. Zhou NAO/BeijingNAO/Beijing

Why Gattini?Why Gattini?

0.27” mean seeing (=550nm) above boundary layer at Dome C (Lawrence et al, Agabi et al) and likely Dome A

Groups want to take the next step2m+ aperture OIR at Dome C

BUT optical sky brightness (including twilight and aurora) largely unquantified GATTINI cameras are giving first estimate of these

parameters essential for ““BIG OPTICAL ASTRONOMY”BIG OPTICAL ASTRONOMY”

Gattini DomeA SBC camera(SBC=Sky Brightness Camera)

Transit camera pointed to South Pole

General features• 2.8 deg x 2.8 deg FoV• 5.1 arsec/pix• Sloan g’, r’, I’ filters

Technical features• Apogee Alta USB CCD camera • 2000x2000 pixels• Thermally controlled to ~ -40C• Objective aperture : 75 mm • Objective focal length: 300 mmSelf-calibrating on stars

Gattini-DomeA Allsky

Transit camera pointed to Zenith

General features• ~90deg x ~90 deg FoV• Bessell B, V, R and long pass red for

OH emission

Technical features• Apogee Alta USB CCD camera • 2000x2000 pixels• Thermally controlled to ~ -40 0C• Objective aperture : ~3.5 mm Self-calibrating on stars

SBC camera works!

Raw image of April 8th 2006 at 23:4840sec exposure

Raw image of July 2nd 2006 at 00:03

40sec exposure

Allsky works !

Raw image of March 29th 200640sec exposure

Satellite trail

SMC

LMC

Field coverage of SBCField coverage of SBC

SBC images 6deg by 4deg centered on SP

~40 sec exp time – no star trails (though not mandatory)

Identify bright stars and use for flux calibration of sky pixel intensity

Produce 2D sky brightness map every 20 mins

Side project- variable star monitoring?

Gattini-Allsky

Transit camera pointed to Zenith

General features• 110deg x 80 deg FoV• Limiting magnitude: mV16/arcsec2

• Full CCD spectral response, no filter

Technical features• Apogee Alta USB CCD camera • 1600x1200 pixels• Thermally controlled to ~ -30 0C• Objective aperture : ~3.5 mm

Self-calibrating on stars

Sky Brightness

• 6.5 months continuous data from the all sky camera gave initial brightness estimates (2006 winter season)

• Brightness values are uncalibrated values across the visual spectrum (this is changed for 2007 data)

• Icing issues with the SBC meant the all sky camera was more appropriate for preliminary analysis (solved for 2007 data)

• Sky brightness with no moon contribution

•M(θ) = Ms - 10(20.32 - 11.66θ)

The sun!

Astronomical darknesssun elevation < -18˚

Astronomical twilightsun elevation > -18˚

UNFILETERED Magnitude

(mag/arcsec2)

sun zenith distance (rad)

moon zenith distance (rad)

-18deg-13deg

(-13deg)

(-39deg)

• Sky brightness with no sun contribution

•M(θ, Φ) = Mm - Φ10(-0.97 - 0.58θ)

The Moon!

Moon phase:Φ = 0%Φ = 50%Φ = 100%

below horizonabove horizon

Magnitude (mag/arcsec2)

moon zenith distance (rad)

moon phase (%)

(+46deg ZD) (-39deg ZD)

MechanicalInterface to PLATO

Gattini DomeA allsky Gattini DomeA SBC

Camera enclosures

OUR HERO!

So, are there clouds or what?

•Photometric images: 83%

•Low extinction images: 85%

•Photometric, low extinction images: 79%

These numbers provide a lower bound on the number of cloud free images for the period April 1 - Oct 12, 2006

CSTAR

Yuanxiang YanTelescopes

Design/Manufacture

Xu ZhouCCD/Computers

All hardware/software modifications

Shang Zhaohui/Zhu ZhenxiProject ManagersIntegration of CSTAR with PLATO

NIAOT/Zhenxi ZhuWinterization

Low temperature experiments

PLATO PRIC

C-STAR: Rapid Response Camera for Wide-Field Imaging

• 10 second exposures• ~ 16th magnitude limit in 10 seconds• ~ 5 degs x 5 Degs fov• 15.77” pixel

Optical Layout: 14.5 cm telescopes x 3

C-STAR Science

• Variables with high temporal resolution photometry in four colours,

• SNe, Novae, Orphan afterglows of bursts.

• Search for extrasolar planets using micro-lensing

• Best light curves of variable objects (stars, AGNs, etc.)

• Statistics of the bright variables

Enabling Technology for the Dome A Survey Telescopes: the STA 10K x 10K CCD

Carl Pennypacker, Berkeley

Don York, Univ. of Chicago

Lifan Wang, Texas A&M

Dick Bredthauer, STA

• 0.5 meter aperture

• 1” pixels (on surface for now)

• 5 deg x 5 deg field of view

Telescope Design: 3x Schmidt Telescopes,

10K x 10K STA on USNO Telescope

Similar CCD’s are on Telescopes Now!

Experienced and Successful CCD Team:

STA (San Juan Capistrano, California) is presently :

• developing CCD's for the LSST

• the Wynn ODI instrument.

• STA President Dick Bredthauer has developed CCD’s for Space Telescope and many planetary missions.

• Uses 1000 Ohm-cm silicon (medium resistivity -- Dalsa is Foundry.

New Read-out Architecture for Drift Scan and Shutter-less Equatorial Tracking (to be built for Dome A AST’s)

Existing Readout Architecture and CCD Quantum Efficiency

Features, etc.:

Dark Current: negligible

Read Noise: ~ electrons at 1 MHz readout

Camera to be developed can work at Ambient of Antarctica (low or no power

on Peltier coolers) or testing in mid-latitudes

What it Looks Like:

Camera Detail:

Camera Detail:

• 100 Supernovae a year, with exquisite light curves

• One ~ Earth mass planet per year, through micro-lensing (in Baade’s window)

• Astro-seismology

• Lots of other variables of interest.

AST3 Science

AST3 Micro-lensing