Publications (143)
MagAO-X: project status and first laboratory results
Jared R. Males, Laird M. Close, Kelsey Miller +32
MagAO-X is an entirely new "extreme" adaptive optics system for the Magellan Clay 6.5 m telescope, funded by the NSF MRI program starting in Sep 2016. The key science goal of MagAO…
An Enigmatic Pointlike Feature within the HD 169142 Transitional Disk
Beth A. Biller, Jared Males, Timothy Rodigas +13
We report the detection of a faint pointlike feature possibly related to ongoing planet-formation in the disk of the transition disk star HD 169142. The pointlike feature has a $Î…
Detection of Nine M8.0-L0.5 Binaries: The Very Low Mass Binary Population and its Implications for Brown Dwarf and VLM Star Formation
Laird M. Close, Nick Siegler, Melanie Freed +1
Use of the highly sensitive Hokupa'a/Gemini curvature wavefront sensor has allowed direct adaptive optics (AO) guiding on very low mass (VLM) stars with SpT=M8.0-L0.5. A survey of…
The Gemini NICI Planet-Finding Campaign: The Offset Ring of HR 4796 A
Zahed Wahhaj, Michael C. Liu, Beth A. Biller +7
We present J, H, CH_4 short (1.578 micron), CH_4 long (1.652 micron) and K_s-band images of the dust ring around the 10 Myr old star HR 4796 A obtained using the Near Infrared Coro…
WIde Separation Planets In Time (WISPIT): A Gap-clearing Planet in a Multi-ringed Disk around the Young Solar-type Star WISPIT 2
Richelle F. van Capelleveen, Christian Ginski, Matthew A. Kenworthy +17
In the past decades several thousand exoplanet systems have been discovered around evolved, main-sequence stars, revealing a wide diversity in their architectures. To understand ho…
Very high contrast IFU spectroscopy of AB Doradus C: 9 mag contrast at 0.2" without a coronagraph using spectral deconvolution
Niranjan Thatte, Roberto Abuter, Matthias Tecza +3
We present an extension of the spectral deconvolution method (Sparks & Ford 2002) to achieve very high contrast at small inner working radii. We apply the method to the specific ca…
An Adaptive Optics Survey of M6.0-M7.5 Stars: Discovery of Three Very Low Mass Binary Systems Including Two Probable Hyades Members
Nick Siegler, Laird M. Close, Eric E. Mamajek +1
A survey of 30 nearby M6.0-M7.5 dwarfs with Ks<12 mag utilizing the Hokupa'a adaptive optics system at the Gemini North Telescope has discovered 3 new binary systems. All 3 systems…
Contrast Enhancement of Binary Star System Using an Optical Vortex Coronagraph
Grover A. Swartzlander, Erin L. Ford, Rukiah S. Abdul-Malik +4
Using an optical vortex coronagraph and simple adaptive optics techniques we have made the first convincing demonstration of an optical vortex coronagraph that is coupled to a star…
Wide Separation Planets In Time (WISPIT): Discovery of a Gap H Protoplanet WISPIT 2b with MagAO-X
Laird M. Close, Richelle F. van Capelleveen, Gabriel Weible +34
Excellent (<25 mas) H images of the star TYC 5709-354-1 led to the discovery of a rare H protoplanet. This star was discovered by the WISPIT survey to have a large multi-…
Design of the MagAO-X Pyramid Wavefront Sensor
Lauren H. Schatz, Jared R. Males, Laird M. Close +11
Adaptive optics systems correct atmospheric turbulence in real time. Most adaptive optics systems used routinely correct in the near infrared, at wavelengths greater than 1 micron.…
HST/WFC3 H Direct-Imaging Detection of a Point-like Source in the Disk Cavity of AB Aur
Yifan Zhou, Aniket Sanghi, Brendan P. Bowler +8
Accreting protoplanets enable the direct characterization of planet formation. As part of a high-contrast imaging search for accreting planets with the Hubble Space Telescope (HST)…
The Gemini NICI Planet-Finding Campaign: The Frequency of Planets around Young Moving Group Stars
Beth A. Biller, Michael C. Liu, Zahed Wahhaj +18
We report results of a direct imaging survey for giant planets around 80 members of the Beta Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra moving groups, observed as pa…
The Gemini NICI Planet-Finding Campaign: Discovery of a Close Substellar Companion to the Young Debris Disk Star PZ Tel
Beth A. Biller, Michael C. Liu, Zahed Wahhaj +24
We report the discovery of a tight substellar companion to the young solar analog PZ Tel, a member of the Beta Pictoris moving group observed with high contrast adaptive optics ima…
Data-driven subspace predictive control of adaptive optics for high-contrast imaging
Sebastiaan Y. Haffert, Jared R. Males, Laird M. Close +11
The search for exoplanets is pushing adaptive optics systems on ground-based telescopes to their limits. One of the major limitations at small angular separations, exactly where ex…
An Advanced Atmospheric Dispersion Corrector: The Magellan Visible AO Camera
Derek Kopon, Laird M. Close, Victor Gasho
In addition to the BLINC/MIRAC IR science instruments, the Magellan adaptive secondary AO system will have an EEV CCD47 that can be used both for visible AO science and as a wide-f…
The Gemini NICI Planet-Finding Campaign
Michael C. Liu, Zahed Wahhaj, Beth A. Biller +21
Our team is carrying out a multi-year observing program to directly image and characterize young extrasolar planets using the Near-Infrared Coronagraphic Imager (NICI) on the Gemin…
An ALMA and MagAO Study of the Substellar Companion GQ Lup B
Ya-Lin Wu, Patrick D. Sheehan, Jared R. Males +6
Multi-wavelength observations provide a complementary view of the formation of young directly-imaged planet-mass companions. We report the ALMA 1.3 mm and Magellan adaptive optics…
A Survey of Close, Young Stars with the Simultaneous Differential Imager (SDI) at the VLT and MMT
Beth A. Biller, Laird M. Close, Elena Masciadri +6
We discuss the preliminary results of a survey of young (<300 Myr), close (<50 pc) stars with the Simultaneous Differential Extrasolar Planet Imager (SDI) implemented at the VLT an…
MagAO-X: Commissioning Results and Status of Ongoing Upgrades
Jared R. Males, Laird M. Close, Sebastiaan Y. Haffert +20
MagAO-X is the coronagraphic extreme adaptive optics system for the 6.5 m Magellan Clay Telescope. We report the results of commissioning the first phase of MagAO-X. Components now…
A Revised Orbital Ephemeris for HAT-P-9b
Jason A. Dittmann, Laird M. Close, Louis J. Scuderi +2
We present here three transit observations of HAT-P-9b taken on 14 February 2010, 18 February 2010, and 05 April 2010 UT from the University of Arizona's 1.55 meter Kuiper telescop…
XPipeline: Starlight subtraction at scale for MagAO-X
Joseph D. Long, Jared R. Males, Sebastiaan Y. Haffert +15
MagAO-X is an extreme adaptive optics (ExAO) instrument for the Magellan Clay 6.5-meter telescope at Las Campanas Observatory in Chile. Its high spatial and temporal resolution can…
Adaptive Optics imaging of VHS 1256-1257: A Low Mass Companion to a Brown Dwarf Binary System
Jordan M. Stone, Andrew J. Skemer, Kaitlin M. Kratter +9
Recently, Gauza et al. (2015) reported the discovery of a companion to the late M-dwarf, VHS J125601.92-125723.9 (VHS 1256-1257). The companion's absolute photometry suggests its m…
Characterizing deformable mirrors for the MagAO-X instrument
Kyle Van Gorkom, Jared R. Males, Laird M. Close +11
The MagAO-X instrument is a new extreme adaptive optics system for high-contrast imaging at visible and near-infrared wavelengths on the Magellan Clay Telescope. A central componen…
Sirius B Imaged in the Mid-Infrared: No Evidence for a Remnant Planetary System
Andrew J. Skemer, Laird M. Close
Evidence is building that remnants of solar systems might orbit a large percentage of white dwarfs, as the polluted atmospheres of DAZ and DBZ white dwarfs indicate the very recent…
Observing Strategies for the NICI Campaign to Directly Image Extrasolar Planets
Beth Biller, Etienne Artigau, Zahed Wahhaj +7
We discuss observing strategy for the Near Infrared Coronagraphic Imager (NICI) on the 8-m Gemini South telescope. NICI combines a number of techniques to attenuate starlight and s…
GMagAO-X: A First Light Coronagraphic Adaptive Optics System for the GMT
Maggie Kautz, Jared R. Males, Laird M. Close +17
GMagAO-X is a visible to NIR extreme adaptive optics (ExAO) system that will be used at first light for the Giant Magellan Telescope (GMT). GMagAO-X is designed to deliver diffract…
The Gemini NICI Planet-Finding Campaign: The Frequency of Giant Planets Around Debris Disk Stars
Zahed Wahhaj, Michael C. Liu, Eric L. Nielsen +17
We have completed a high-contrast direct imaging survey for giant planets around 57 debris disk stars as part of the Gemini NICI Planet-Finding Campaign. We achieved median H-band…
The Gemini NICI Planet-Finding Campaign: Discovery of a Multiple System Orbiting the Young A Star HD 1160
Eric L. Nielsen, Michael C. Liu, Zahed Wahhaj +22
We report the discovery by the Gemini NICI Planet-Finding Campaign of two low-mass companions to the young A0V star HD 1160 at projected separations of 81 +/- 5 AU (HD 1160 B) and…
Discovery of a 66 mas Ultracool Binary with Laser Guide Star Adaptive Optics
Nick Siegler, Laird M. Close, Adam J. Burgasser +4
We present the discovery of 2MASS J21321145+1341584AB as a closely separated (0.066") very low-mass field dwarf binary resolved in the near-infrared by the Keck II Telescope using…
The Intricate Structure of HH 508, the Brightest Microjet in the Orion Nebula
Ya-Lin Wu, Laird M. Close, Jinyoung Serena Kim +2
We present Magellan adaptive optics H imaging of HH 508, which has the highest surface brightness among protostellar jets in the Orion Nebula. We find that HH 508 actually has…
The Holographic Dispersed Fringe Sensors (HDFS): phasing the Giant Magellan Telescope
Sebastiaan Y. Haffert, Laird M. Close, Alexander D. Hedglen +14
The next generation of Giant Segmented Mirror Telescopes (GSMT) will have large gaps between the segments either caused by the shadow of the mechanical structure of the secondary m…
SEEDS Adaptive Optics Imaging of the Asymmetric Transition Disk Oph IRS 48 in Scattered Light
Katherine B. Follette, Carol A. Grady, Jeremy R. Swearingen +60
We present the first resolved near infrared imagery of the transition disk Oph IRS 48 (WLY 2-48), which was recently observed with ALMA to have a strongly asymmetric sub-millimeter…
NICI: combining coronagraphy, ADI, and SDI
Etienne Artigau, Beth A. Biller, Zahed Wahhaj +9
The Near-Infrared Coronagraphic Imager (NICI) is a high-contrast AO imager at the Gemini South telescope. The camera includes a coronagraphic mask and dual channel imaging for Spec…
Dense Molecular Gas In A Young Cluster Around MWC 1080 -- Rule Of The Massive Star
Shiya Wang, Leslie W. Looney, Wolfgang Brandner +1
We present CS , CO , and CO , observations with the 10-element Berkeley Illinois Maryland Association (BIMA) Array toward the y…
Evidence Against an Edge-On Disk Around the Extrasolar Planet 2MASS 1207 b and a New Thick Cloud Explanation for its Under-Luminosity
Andrew J. Skemer, Laird M. Close, László Szűcs +3
(Abridged) Since the discovery of the first directly-imaged, planetary-mass object, 2MASS 1207 b, several works have sought to explain a disparity between its observed temperature…
An Adaptive Optics Survey of M8-M9 Stars: Discovery of 4 Very Low mass Binaries With at Least One System Containing a Brown Dwarf Companion
Laird M. Close, Nick Siegler, Dan Potter +2
Use of the highly sensitive Hokupa'a/Gemini curvature wavefront sensor has allowed for the first time direct adaptive optics (AO) guiding on M8-M9 very low mass (VLM) stars. An ini…
HD 106906 b: A planetary-mass companion outside a massive debris disk
Vanessa Bailey, Tiffany Meshkat, Megan Reiter +14
We report the discovery of a planetary-mass companion, HD 106906 b, with the new Magellan Adaptive Optics (MagAO) + Clio2 system. The companion is detected with Clio2 in three band…
Companion Mass Limits for 17 Binary Systems Obtained with Binary Differential Imaging and MagAO/Clio
Logan A. Pearce, Jared R. Males, Alycia J. Weinberger +4
Improving direct detection capability close to the star through improved star-subtraction and post-processing techniques is vital for discovering new low-mass companions and charac…
Discovery of H Emission from a Protoplanet Candidate Around the Young Star 2MASS J16120668-3010270 with MagAO-X
Jialin Li, Laird M. Close, Feng Long +32
2MASS J16120668-3010270 (hereafter 2MJ1612) is a young M0 star that hosts a protoplanetary disk in the Upper Scorpious star-forming region. Recent ALMA observations of 2MJ1612 show…
Magellan Adaptive Optics Imaging of PDS 70: Measuring the Mass Accretion Rate of a Young Giant Planet within a Gapped Disk
Kevin Wagner, Katherine B. Follette, Laird M. Close +11
PDS 70b is a recently discovered and directly imaged exoplanet within the wide (40 au) cavity around PDS 70 (Keppler et al. 2018, Müller et al. 2018). Ongoing accretion o…
A locking clamp that enables high thermal and vibrational stability for kinematic optical mounts
Maggie Kautz, Laird M. Close, Jared R. Males
One of the main pursuits of the MagAO-X project is imaging planets around nearby stars with the direct detection method utilizing an extreme AO system and a coronagraph and a large…
The conceptual design of GMagAO-X: visible wavelength high contrast imaging with GMT
Jared R. Males, Laird M. Close, Sebastiaan Y. Haffert +10
We present the conceptual design of GMagAO-X, an extreme adaptive optics system for the 25 m Giant Magellan Telescope (GMT). We are developing GMagAO-X to be available at or shortl…
Optical and mechanical design of the extreme AO coronagraphic instrument MagAO-X
Laird M. Close, Jared R. Males, Olivier Durney +9
Here we review the current optical mechanical design of MagAO-X. The project is post-PDR and has finished the design phase. The design presented here is the baseline to which all t…
ALMA Discovery of a Disk around the Planetary-mass Companion SR 12 c
Ya-Lin Wu, Brendan P. Bowler, Patrick D. Sheehan +6
We report an Atacama Large Millimeter/submillimeter Array 0.88 mm (Band 7) continuum detection of the accretion disk around SR 12 c, an 11 planetary-mass compan…
High-contrast imaging in the Hyades with snapshot LOCI
Katie M. Morzinski, Bruce A. Macintosh, Laird M. Close +3
To image faint substellar companions obscured by the stellar halo and speckles, scattered light from the bright primary star must be removed in hardware or software. We apply the "…
The Optical and Mechanical Design for the 21,000 Actuator ExAO System for the Giant Magellan Telescope: GMagAO-X
Laird M. Close, Jared R. Males, Olivier Durney +9
GMagAO-X is the near first light ExAO coronagraphic instrument for the 25.4m GMT. It is designed for a slot on the folded port of the GMT. To meet the strict ExAO fitting and servo…
Status of MagAO and review of astronomical science with visible light adaptive optics
Laird M. Close, Jared R. Males, Katie M. Morzinski +10
We review astronomical results in the visible (lambda <1 micron) with adaptive optics and note the status the MagAO system and the recent upgrade to visible camera's Simultaneous/S…
Phasing the Giant Magellan Telescope: Lab Experiments and First On-sky Demonstration
Maggie Y. Kautz, Sebastiaan Y. Haffert, Laird M. Close +21
The large apertures of the upcoming generation of Giant Segmented Mirror Telescopes will enable unprecedented angular resolutions that scale as /D and higher sensitiv…
The Magellan Adaptive Secondary VisAO Camera: Diffraction- Limited Broadband Visible Imaging and 20mas Fiber Array IFS
Derek Kopon, Laird M. Close, Jared R. Males +2
The Magellan Adaptive Secondary AO system, scheduled for first light in the fall of 2011, will be able to simultaneously perform diffraction limited AO science in both the mid-IR,…
Approaches to lowering the cost of large space telescopes
Ewan S Douglas, Greg Aldering, Greg W. Allan +26
New development approaches, including launch vehicles and advances in sensors, computing, and software, have lowered the cost of entry into space, and have enabled a revolution in…
The Gemini NICI Planet-Finding Campaign : Discovery of a Substellar L Dwarf Companion to the Nearby Young M Dwarf CD-35 2722
Zahed Wahhaj, Michael C. Liu, Beth A. Biller +23
We present the discovery of a wide (67 AU) substellar companion to the nearby (21 pc) young solar-metallicity M1 dwarf CD-35 2722, a member of the ~100 Myr AB Doradus association.…
Design, implementation, and on-sky performance of an advanced apochromatic triplet atmospheric dispersion corrector for the Magellan adaptive optics system and VisAO camera
Derek Kopon, Laird M. Close, Jared R. Males +1
We present the novel design, laboratory verification, and on-sky performance of our advanced triplet atmospheric dispersion corrector (ADC), an important component of the Magellan…
Constraints on Extrasolar Planet Populations from VLT NACO/SDI and MMT SDI and Direct Adaptive Optics Imaging Surveys: Giant Planets are Rare at Large Separations
Eric L. Nielsen, Laird M. Close, Beth A. Biller +2
We examine the implications for the distribution of extrasolar planets based on the null results from two of the largest direct imaging surveys published to date. Combining the mea…
A Reflective Gaussian Coronagraph for ExAO: Laboratory Performance
Ryeojin Park, Laird M. Close, Nick Siegler +2
We report laboratory results of a coronagraphic test bench to assess the intensity reduction differences between a "Gaussian" tapered focal plane coronagraphic mask and a classical…
A Multiband Study of the HR 4796A Disk in the Optical Using MagAO-X
Jay K. Kueny, Alycia J. Weinberger, Zhe-Yu Daniel Lin +18
We present total intensity images of the debris disk around HR 4796A from observations spanning 2023 to 2025 with the Magellan extreme adaptive optics instrument (MagAO-X). We dete…
Status Update and Closed-Loop Performance of the Magellan Adaptive Optics VisAO Camera
Derek Kopon, Laird M. Close, Jared Males +3
We present laboratory results of the closed-loop performance of the Magellan Adaptive Optics (AO) Adaptive Secondary Mirror (ASM), pyramid wavefront sensor (PWFS), and VisAO visibl…
The Gemini NICI Planet-Finding Campaign: The Companion Detection Pipeline
Zahed Wahhaj, Michael C. Liu, Beth A. Biller +7
We present the high-contrast image processing techniques used by the Gemini NICI Planet-Finding Campaign to detect faint companions to bright stars. NICI (Near Infrared Coronagraph…
The Giant Magellan Telescope high contrast adaptive optics phasing testbed (p-HCAT): lab tests of segment/petal phasing with a pyramid wavefront sensor and a holographic dispersed fringe sensor (HDFS) in turbulence
Alexander D. Hedglen, Laird M. Close, Sebastiaan Y. Haffert +14
The Giant Magellan Telescope (GMT) design consists of seven circular 8.4-m diameter mirror segments that are separated by large > 30 cm gaps, creating the possibility of fluctuatio…
Follow-up Observations of the Neptune Mass Transiting Extrasolar Planet HAT-P-11b
Jason A. Dittmann, Laird M. Close, Elizabeth M. Green +2
We have confirmed the existence of the transiting super Neptune extrasolar planet HAT-P-11b. On May 1, 2009 UT the transit of HAT-P-11b was detected at the University of Arizona's…
Advanced wavefront sensing and control demonstration with MagAO-X
Sebastiaan Y. Haffert, Jared R. Males, Kyle Van Gorkom +13
The search for exoplanets is pushing adaptive optics systems on ground-based telescopes to their limits. Currently, we are limited by two sources of noise: the temporal control err…
New Spatially Resolved Observations of the T Cha Transition Disk and Constraints on the Previously Claimed Substellar Companion
S. Sallum, J. A. Eisner, Laird M. Close +11
We present multi-epoch non-redundant masking observations of the T Cha transition disk, taken at the VLT and Magellan in H, Ks, and L' bands. T Cha is one of a small number of tran…
HIP 67506 C: MagAO-X Confirmation of a New Low-Mass Stellar Companion to HIP 67506 A
Logan A. Pearce, Jared R. Males, Sebastiaan Y. Haffert +17
We report the confirmation of HIP 67506 C, a new stellar companion to HIP 67506 A. We previously reported a candidate signal at 2/D (240~mas) in L in MagAO/Clio imag…
The Multiplicity of M-Dwarfs in Young Moving Groups
Yutong Shan, Jennifer C. Yee, Brendan P. Bowler +11
We image 104 newly identified low-mass (mostly M-dwarf) pre-main sequence members of nearby young moving groups with Magellan Adaptive Optics (MagAO) and identify 27 binaries with…
On-sky performance analysis of the vector Apodizing Phase Plate coronagraph on MagAO/Clio2
Gilles P. P. L. Otten, Frans Snik, Matthew A. Kenworthy +9
We report on the performance of a vector apodizing phase plate coronagraph that operates over a wavelength range of m and is installed in MagAO/Clio2 at the 6.5 m Magellan…
Applying a temporal systematics model to vector Apodizing Phase Plate coronagraphic data: TRAP4vAPP
Pengyu Liu, Alexander J. Bohn, David S. Doelman +10
The vector Apodizing Phase Plate (vAPP) is a pupil plane coronagraph that suppresses starlight by forming a dark hole in its point spread function (PSF). The unconventional and non…
Concept for the GMT High-Contrast Exoplanet Instrument GMagAO-X and the GMT High-Contrast Phasing Testbed with MagAO-X
Laird M. Close, Jared R. Males, Alex Hedglen +2
Here we review the current conceptual optical mechanical design of GMagAO-X --the extreme AO (ExAO) system for the Giant Magellan Telescope (GMT). The GMagAO-X tweeter deformable m…
Direct Exoplanet Detection with Binary Differential Imaging
Timothy J. Rodigas, Alycia Weinberger, Eric E. Mamajek +5
Binaries are typically excluded from direct imaging exoplanet surveys. However, the recent findings of Kepler and radial velocity programs show that planets can and do form in bina…
MagAO: Status and Science
Katie M. Morzinski, Laird M. Close, Jared R. Males +10
"MagAO" is the adaptive optics instrument at the Magellan Clay telescope at Las Campanas Observatory, Chile. MagAO has a 585-actuator adaptive secondary mirror and 1000-Hz pyramid…
The Gemini NICI Planet-Finding Campaign: The Frequency of Giant Planets around Young B and A Stars
Eric L. Nielsen, Michael C. Liu, Zahed Wahhaj +22
We have carried out high contrast imaging of 70 young, nearby B and A stars to search for brown dwarf and planetary companions as part of the Gemini NICI Planet-Finding Campaign. O…
Imaging protoplanets: observing transition disks with non-redundant masking
Steph Sallum, Josh Eisner, Laird M. Close +17
Transition disks, protoplanetary disks with inner clearings, are promising objects in which to directly image forming planets. The high contrast imaging technique of non-redundant…
Magellan Adaptive Optics first-light observations of the exoplanet Pic b. I. Direct imaging in the far-red optical with MagAO+VisAO and in the near-IR with NICI
Jared R. Males, Laird M. Close, Katie M. Morzinski +20
We present the first ground-based CCD (m) image of an extrasolar planet. Using MagAO's VisAO camera we detected the extrasolar giant planet (EGP) Pictoris b in -sh…
Discovery and Validation of a High-Density sub-Neptune from the K2 Mission
Néstor Espinoza, Rafael Brahm, Andrés Jordán +12
We report the discovery of BD+20594b, a high density sub-Neptune exoplanet, made using photometry from Campaign 4 of the two-wheeled Kepler (K2) mission, ground-based radial veloci…
High-Contrast Imaging at First-Light of the GMT: The Preliminary Design of GMagAO-X
Jared R. Males, Laird M. Close, Sebastiaan Y. Haffert +15
We present the preliminary design of GMagAO-X, the first-light high-contrast imager planned for the Giant Magellan Telescope. GMagAO-X will realize the revolutionary increase in sp…
The Visible Integral-field Spectrograph eXtreme (VIS-X): high-resolution spectroscopy with MagAO-X
Sebastiaan Y. Haffert, Jared R. Males, Laird M. Close +9
MagAO-X system is a new adaptive optics for the Magellan Clay 6.5m telescope. MagAO-X has been designed to provide extreme adaptive optics (ExAO) performance in the visible. VIS-X…
The Separation and H-alpha Contrasts of Massive Accreting Planets in the Gaps of Transitional Disks: Predicted H-alpha Protoplanet Yields for Adaptive Optics Surveys
Laird M. Close
We present a massive accreting gap (MAG) planet model that ensures large gaps in transitional disks are kept dust free by the scattering action of three co-planar quasi-circular pl…
Discovery of a Tight Brown Dwarf Companion to the Low Mass Star LHS 2397a
Melanie Freed, Laird M. Close, Nick Siegler
Using the adaptive optics system, Hokupa'a, at Gemini-North, we have directly imaged a companion around the UKIRT faint standard M8 star, LHS 2397a (FS 129) at a separation of 2.96…
Improved companion mass limits for Sirius A with thermal infrared coronagraphy using a vector-apodizing phase plate and time-domain starlight-subtraction techniques
Joseph D. Long, Jared R. Males, Sebastiaan Y. Haffert +12
We use observations with the infrared-optimized MagAO system and Clio camera in 3.9 m light to place stringent mass constraints on possible undetected companions to Sirius A. W…
Direct imaging of exoplanets in the habitable zone with adaptive optics
Jared R. Males, Laird M. Close, Olivier Guyon +16
One of the primary goals of exoplanet science is to find and characterize habitable planets, and direct imaging will play a key role in this effort. Though imaging a true Earth ana…
High-contrast observations of brown dwarf companion HR 2562 B with the vector Apodizing Phase Plate coronagraph
Ben J. Sutlieff, Alexander J. Bohn, Jayne L. Birkby +8
The vector Apodizing Phase Plate (vAPP) is a class of pupil plane coronagraph that enables high-contrast imaging by modifying the Point Spread Function (PSF) to create a dark hole…
Direct Imaging in the Habitable Zone and the Problem of Orbital Motion
Jared R. Males, Andrew J. Skemer, Laird M. Close
High contrast imaging searches for exoplanets have been conducted on 2.4-10 m telescopes, typically at H band (1.6 microns) and used exposure times of ~1 hr to search for planets w…
MagAO Imaging of Long-period Objects (MILO). I. A Benchmark M Dwarf Companion Exciting a Massive Planet around the Sun-like Star HD 7449
Timothy J. Rodigas, Pamela Arriagada, Jackie Faherty +17
We present high-contrast Magellan adaptive optics (MagAO) images of HD 7449, a Sun-like star with one planet and a long-term radial velocity (RV) trend. We unambiguously detect the…
The very nearby M/T dwarf binary SCR 1845-6357
Markus Kasper, Beth A. Biller, Adam Burrows +3
The recently discovered star SCR 1845-6357 is the first late M/T dwarf binary discovered. SCR 1845 is a particular object due to its tight orbit (currently around 4 AU) and its pro…
Multiwavelength Observations of NaSt1 (WR 122): Equatorial Mass Loss and X-rays from an Interacting Wolf-Rayet Binary
Jon C. Mauerhan, Nathan Smith, Schuyler D. Van Dyk +5
NaSt1 (aka Wolf-Rayet 122) is a peculiar emission-line star embedded in an extended nebula of [N II] emission with a compact dusty core. This object was characterized by Crowther &…
Resolving the Dusty Circumstellar Structure of the Enigmatic Symbiotic Star CH Cygni with the MMT Adaptive Optics System
Beth A. Biller, Laird M. Close, Aigen Li +6
We imaged the symbiotic star CH Cyg and two PSF calibration stars using the unique 6.5m MMT deformable secondary adaptive optics system. Our high-resolution (FWHM=0.3"), very high…
On-sky, real-time optical gain calibration on MagAO-X using incoherent speckles
Eden A. McEwen, Jared R. Males, Olivier Guyon +15
The next generation of extreme adaptive optics (AO) must be calibrated exceptionally well to achieve the desired contrast for ground-based direct imaging exoplanet targets. Current…
Dust Grain Evolution in Spatially Resolved T Tauri Binaries
Andrew J. I. Skemer, Laird M. Close, Thomas P. Greene +3
Core-accretion planet formation begins in protoplanetary disks with the growth of small, ISM dust grains into larger particles. The progress of grain growth, which can be quantifie…
Five New Sirius-Like White Dwarf + Main Sequence Star Systems with MagAO-X
Logan A. Pearce, Jared R. Males, Sebastiaan Y. Haffert +20
Most known white dwarfs in multiple systems with main sequence stars have been discovered with M-type companions, because the white dwarf causes detectable UV excess and bluer colo…
Three-sided pyramid wavefront sensor. II. Preliminary demonstration on the new CACTI testbed
Lauren Schatz, Johanan Codona, Joseph D. Long +17
The next generation of giant ground and space telescopes will have the light-collecting power to detect and characterize potentially habitable terrestrial exoplanets using high-con…
An Optical/near-infrared investigation of HD 100546 b with the Gemini Planet Imager and MagAO
Julien Rameau, Katherine B. Follette, Laurent Pueyo +52
We present H band spectroscopic and Halpha photometric observations of HD 100546 obtained with GPI and MagAO. We detect H band emission at the location of the protoplanet HD 100546…
A planetary-mass candidate imaged in the Young Suns Exoplanet Survey
Pengyu Liu, Matthew A. Kenworthy, Beth A. Biller +26
Directly imaged exoplanets in wide orbits challenge current gas giant formation theories. They need to form quickly and acquire enough material before the disk dissipates, which ca…
Low-amplitude solar-like oscillations in the K5 V star Indi A
Mia S. Lundkvist, Hans Kjeldsen, Timothy R. Bedding +17
We have detected solar-like oscillations in the mid K-dwarf Indi A, making it the coolest dwarf to have measured oscillations. The star is noteworthy for harboring a…
MagAO: Status and on-sky performance of the Magellan adaptive optics system
Katie M. Morzinski, Laird M. Close, Jared R. Males +19
MagAO is the new adaptive optics system with visible-light and infrared science cameras, located on the 6.5-m Magellan "Clay" telescope at Las Campanas Observatory, Chile. The inst…
ffortissimo: A Freeform Forward-Modeling Pipeline for High-Contrast Images of Circumstellar Disks Based on Automatic Differentiation
Jay K. Kueny, Joseph D. Long, Jared R. Males +16
Modeling circumstellar disks in the traditional sense carries the assumption that the dust density distribution can be accurately described with a fixed parametric form. Furthermor…
The Gemini NICI Planet-Finding Campaign: The Orbit of the Young Exoplanet beta Pictoris b
Eric L. Nielsen, Michael C. Liu, Zahed Wahhaj +12
We present new astrometry for the young (12--21 Myr) exoplanet beta Pictoris b taken with the Gemini/NICI and Magellan/MagAO instruments between 2009 and 2012. The high dynamic ran…
Phase-Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC) on-sky demonstration with MagAO-X
Elena Tonucci, Sebastiaan Haffert, Warren Foster +18
Advancing the technological development of small inner working angle (IWA) coronagraphs is essential to enabling high-contrast imaging of temperate exoplanets with future extremely…
The hunt for Sirius Ab: Comparison of algorithmic sky and PSF estimation performance in deep coronagraphic thermal-IR high contrast imaging
Joseph D. Long, Jared R. Males, Katie M. Morzinski +7
Despite promising astrometric signals, to date there has been no success in direct imaging of a hypothesized third member of the Sirius system. Using the Clio instrument and MagAO…
A Tentative Detection of a Starspot During Consecutive Transits of an Extrasolar Planet from the Ground: No Evidence of a Double Transiting Planet System Around TrES-1
Jason A. Dittmann, Laird M. Close, Elizabeth M. Green +1
There have been numerous reports of anomalies during transits of the planet TrES-1b. Recently, Rabus and coworkers' analysis of HST observations lead them to claim brightening anom…
Improved Orbital Constraints and H Photometric Monitoring of the Directly Imaged Protoplanet Analog HD 142527 B
William O. Balmer, Katherine B. Follette, Laird M. Close +9
Companions embedded in the cavities of transitional circumstellar disks have been observed to exhibit excess luminosity at H, an indication that they are actively accreting. We…
Enabling Technologies for Visible Adaptive Optics: The Magellan Adaptive Secondary VisAO Camera
Derek Kopon, Jared R. Males, Laird M. Close +1
Since its beginnings, diffraction-limited ground-based adaptive optics (AO) imaging has been limited to wavelengths in the near IR (λ > 1 micron) and longer. Visible AO (λ < 1 mi…
The Gemini NICI Planet-Finding Campaign: Asymmetries in the HD 141569 disc
Beth A. Biller, Michael C. Liu, Ken Rice +8
We report here the highest resolution near-IR imaging to date of the HD 141569A disc taken as part of the NICI Science Campaign. We recover 4 main features in the NICI images of th…