DOCSLIB.ORG

A Planetary-Mass Companion Candidate 2M1207

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Planetary-Mass Companion Candidate 2M1207 2M1207_PR file:///d3/gschneid/EONSWEB/10176/2M1207_AAS/2M1207_PR.html EMBARGOED -- FOR RELEASE: 09:20 A.M. PST, January 10, 2005 To Be Presented at: AAS 205th Meeting, San Diego, California Session 11.14 - Brown Dwarfs and Exoplanets -- Monday, January 10, 2005 NICMOS Imaging of 2MASSWJ 1207334-393254 - A Planetary-Mass Companion Candidate Paper Presented by: Glenn Schneider (Steward Observatory, University of Arizona) Inseok Song (Gemini Observatory) Ben Zuckerman, E. Becklin (UCLA), Patrick Lowrance (Caltech) Bruce Macintosh (Lowrance Livermore National Laboratory) Michael Bessell (Australian National University) Christophe Dumas, Gail Chauvin (European Southen Observatory) Contact: Glenn Schneider, 520-621-5865, [email protected] Click for ABSTRACT OF PAPER to be subtracted. Available via the web after the embargo date: http://nicmosis.as.arizona.edu:8000/AAS_JAN_2004/PR_11_14.html 2M1207 - Closing in on an Extra-Solar Planet: the HST/AO Symbiosis 2MASSWJ 1207334-393254 (aka 2M1207) is a young brown dwarf (estimated age 8 million years) approximately 70 parsecs (225 light years) from the Earth. In April 2004 , using an infra-red camera on the Very Large Telescope (VLT) in Chile augmented with an adaptive optics (AO) system, astronomers spotted a feeble point of light (1/100th as bright as 2M1207 itself at the wavelengths of their observations) in close angular proximity to 2M1207, 778 thousandths of an arc second (less than a mile at the distance of the moon) away. Those observations suggested the possibility of the object being a giant planet companion to 2M1207, as recently reported in Astronomy & Astrophysics by Chauvin et al. If confirmed 2M1207"b" would represent the first image of a planetary mass object gravitationally bound to a star - other than the Sun. Contemporaneously, the Hubble Space Telescope (HST) was preparing to execute an imaging survey of 116 comparably young and nearby stars (then to begin in July 2004 and now under way) to search for such objects - a survey that also included 2M1207. The HST survey team was advised by the VLT researchers of the Giant Planet Companion Candidate (GPCC) they had detected, and the HST observation of this star was re-planned from a survey/detection mode to one of characterization and, to the extent possible on a very short timescale, confirmation. "Second epoch" observations were carried out with HST's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) in August 2004. Those observations of 2M1207 and its GPCC provided high resolution images at the short wavelength end of the near-infrared spectrum which cannot be obtained from the ground. Ground-based AO, though a potentially powerful technique to sharpen "fuzzy" infra- red images blurred by the Earth's atmosphere, degrades in capability with decreasing wavelength, specifically at those wavelengths where key "color" diagnostics would specifically inform on the physical nature of 2M1207's GPCC. Thus, HST/NICMOS images were obtained at three "short" near-IR wavelengths: 0.9 microns where the GPCC was 44 times fainter than the shortest (1.6 micron) wavelength where it was detected with VLT, 1.1 microns to provide a second color diagnostic (also undetectable with 1 of 6 12/23/04 3:59 PM 2M1207_PR file:///d3/gschneid/EONSWEB/10176/2M1207_AAS/2M1207_PR.html VLT), and also longer 1.6 micron (H-band) images to compare directly with the shortest wavelength VLT image in the same spectral region. These observations found the object to be extremely "red" and relatively much brighter at longer wavelengths - both within the NICMOS spectral bands but also in comparison to the even longer wavelength VLT observations. The multi-band color indices and wavelength-dependent brightnesses (flux densities) match theoretical expectations for an 8 million year old object about five times as massive as Jupiter. Earlier, the VLT researchers had also obtained a low-resolution spectrum of the GPCC longward of appx 1.4 microns. That spectrum, similar in many respects to what one might expect from an L-dwarf star with a temperature of approximately 1250 degrees on the Kelvin scale, included a broad spectral absorption feature which is attributed to water thus further implicating the possibility of a the object's true nature as a hot giant planet. Additional broad spectral diagnostics at shorter wavelengths could not be obtained due to the limitations of ground-based AO, hence the need for space observations. Conservatively, the colors, flux densities, and possibility of H2O cannot unambiguously identify the GPCC as a planet. The ultimate arbiter is the establishment of common proper motion of 2M1207 and the GPCC - i.e., if both objects are seen to move through space as a gravitationally bound pair. 2M1207 has the spectral signature of a very low mass star which, because of its youth, belies its true nature as a brown dwarf only 25 times the mass of Jupiter. The GPCC, if gravitationally bound is at a projected (minimum) distance of approximately 54 Astronomical Units from 2M1207 (about 1/3 again further away than Pluto is from the Sun). Given the mass of 2M1207 (appx 2.4% that of the Sun), as inferred from its spectral type (M8.5) and age, the GPCC would have an orbital period of at least 2500 years. Hence, any relative motion seen between the two on much shorter time scales would reveal the GPCC to be a background interloper. The very high precision relative position measures obtained with the HST/NICMOS images observations were used in combination with the earlier VLT observations to test the possibility of physical companionship by common proper motion. The August 28, 2004 NICMOS observation placed the GPCC 773.7 +/- 2.2 thousands of an arcsecond from 2M1207. Despite the only four months between the VLT and NICMOS observations the likelihood of the object being not being an ill-placed background object (without invoking the implications of colors and flux densities indicative of a planetary mass object) was confirmed at the 99.1% level of confidence. But, even those "odds" are not good enough for conservative astronomers to claim victory. The precision of this measurement with the images now in hand is predominantly limited by the systemic astrometric calibration of the VLT/NACO AO observations and our current knowledge of the proper motion of 2M1207 itself. The uncertainty in follow-up differential position measures would naturally decline with a sufficiently longer temporal baseline. Such follow-up HST/NICMOS observations are planned for April 2005 (the next possible scheduling opportunity). If the 2nd/3rd epoch (NICMOS/NICMOS) differential proper motions continue to track as suggested by the 1st/2nd epoch (VLT/NICMOS) observations a differential measure would be secured to reject the possibility of a the GPCC being a background source at greater than the 7 sigma level (i.e., effectively at the 100% confidence level). The HST/NICMOS and VLT/NACO observations of 2M1207 and its GPCC clearly demonstrate the complementary nature and symbiosis between space and ground-based astronomy using state of the art observing techniques and instrumentation. Each is contributing importantly where uniquely suited to assembling the pieces of the jigsaw puzzle in the quest for images of extrasolar planets. FIGURE 1 2 of 6 12/23/04 3:59 PM 2M1207_PR file:///d3/gschneid/EONSWEB/10176/2M1207_AAS/2M1207_PR.html Figure 1 Caption - NICMOS Camera 1 images of 2M1207's GPCC at three increasingly longer near-infrared wavelengths. Left to right 0.9, 1.1, and 1.6 microns. The light from 2M1207 itself has been greatly reduced by subtracting a second image of the star taken with HST rolled to a different orientation in the sky. Imperfections in the "differential roll" subtraction technique give rise to optical artifacts at the location of 2M1207 which is centered in the red circle of 0.2 arc second radius. In subtraction, a negative imprint of the GPCC also arises (see Figure 3) which has been removed from these images in the differential roll image recombination process. 2M1207, a young brown dwarf of spectral type M8.5 is itself quite red -- 11 times fainter at 0.9 microns than it is at 1.6 microns. The GPCC at 0.9 microns is significantly redder in comparison, 44 times fainter at 1.6 microns than it is at 0.9 microns where, at that shorter wavelength, it is also 720 times fainter than 2M1207. Technical notes: 1. Each image is stretched to show the brightness of the GPCC with respect to the noise in the image background at the -2 sigma (from zero) level. 2. In the 1.1 and 1.6 micron images the first Airy ring, arising the HST diffraction pattern of an unresolved point source which scales linearly with wavelength, around the GPCC is seen. 3. Each image is 2.5" x 2.5". 4. Before subtraction, for images were obtained at each of the two field orientations in each filter and combined to provide better image sampling. 5. Total exposure times are as follows: 0.9 microns = 2560 seconds, 1.1 microns = 2048 seconds, 1.6 microns = 448 seconds. FIGURE 2 3 of 6 12/23/04 3:59 PM 2M1207_PR file:///d3/gschneid/EONSWEB/10176/2M1207_AAS/2M1207_PR.html Figure 2 Caption - Three spectral band "color" composite image of the GPCC. The background light due to 2M1207 in the individually filtered images has been greatly reduced by the differential roll subtraction and image recombination technique. Red = 1.6 microns (F160W filter), Green = 1.1 microns (F110M filter), Blue = 0.90 microns (F090M filter). The magnitude of the image processing artifacts within the gray masked region (inside the red circle) and extending to an angular distance of 0.2 arc seconds from the 2M1207 (at the location of the "+" sign) at the shorter (bluer) wavelengths dominate the roll-subtraction residuals and represents a "here be dragons" regions which cannot be probed in this manner.
Load more

Recommended publications
  • Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
    Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born.
    [Show full text]
  • The Copernican Principle Rules out BLC1 As a Technological Radio Signal from the Alpha Centauri System
    Draft version January 13, 2021 Typeset using LATEX twocolumn style in AASTeX62 The Copernican Principle Rules Out BLC1 as a Technological Radio Signal from the Alpha Centauri System Amir Siraj1 and Abraham Loeb1 1Department of Astronomy, Harvard University, 60 Garden Street, Cambridge, MA 02138, USA ABSTRACT Without evidence for occupying a special time or location, we should not assume that we inhabit privileged circumstances in the Universe. As a result, within the context of all Earth-like planets orbiting Sun-like stars, the origin of a technological civilization on Earth should be considered a single outcome of a random process. We show that in such a Copernican framework, which is inherently optimistic about the prevalence of life in the Universe, the likelihood of the nearest star system, Alpha Centauri, hosting a radio-transmitting civilization is ∼ 10−8. This rules out, a priori, Breakthrough Listen Candidate 1 (BLC1) as a technological radio signal from the Alpha Centauri system, as such a scenario would violate the Copernican principle by about eight orders of magnitude. We also show that the Copernican principle is consistent with the vast majority of Fast Radio Bursts being natural in origin. Keywords: technosignatures; astrobiology; search for extraterrestrial intelligence; biosignatures 1. INTRODUCTION lihood of searches for primitive and intelligent life, us- The Copernican principle asserts that we are not priv- ing a Drake-type approach. Westby & Conselice(2020) ileged observers of the Universe. Successes of its appli- applied the Copernican principle to the search for intel- cation include the rejection of Ptolemaic geocentrism ligent life, but in forms that featured strict boundaries and the adoption of the modern cosmological princi- in time, thereby not reflecting a truly random process.
    [Show full text]
  • YETI – Search for Young Transiting Planets
    YETI – search for young transiting planets Ronny Errmann, Astrophysikalisches Institut und Universitäts-Sternwarte Jena, in collaboration with: Ralph Neuhäuser, AIU Jena Gracjan Maciejewski, Centre for Astronomy of the Nicolaus Copernicus University Ronald Redmer, University of Rostock Martin Seeliger, AIU Jena YETI Observers, all over the world Mercury transit Hot Planets and Cool Stars 8. Nov. 06 (SOHO) Garching 12. November 2012 Venus transit 6. June 12 Motivation youngest transiting planets: ●Corot 2: 130 – 500 Myr (from star spots) 30 – 40 Myr (from planet radius) ●Corot 20: 100 – 800 Myr (from Li-abundance) M = 1 MJup ●Wasp 10: 200 – 350 Myr (from gyro-chronology) → younger transiting planets (Radius+true Mass) needed, to test models, and planet formation scenarios Observation strategies increase probability for transiting planet: monitoring of many young stars -> Young open clusters orbital periods: ~1 to ~10 days transit duration: ~1 to few hours → 1 to 5% of orbit in transit phase observation with single telescope: data gaps because of daytime, weather, ... increase probability for observing transit signal: long continuous observation -> YETI YETI-network (Young Exoplanet Transit Initiative) Tenagra II Llano del Gettysburg Sierra Nevada Jena Stara Lesna Byurakan Xinglong Gunma Hato Astrophysical 0.8-m telescope Observatory Collage Astronomical 1.0 and 2.6 Observatory Astronomical 1.5-m telescope Institute Observatory Institute telescopes 90/60 cm Observatory 0.9/0.6-m 0.6-m telescope 1.5-m telescope 1-m Schmidt 0.4-m telescope
    [Show full text]
  • Naming the Extrasolar Planets
    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
    [Show full text]
  • Observing Exoplanets
    Observing Exoplanets Olivier Guyon University of Arizona Astrobiology Center, National Institutes for Natural Sciences (NINS) Subaru Telescope, National Astronomical Observatory of Japan, National Institutes for Natural Sciences (NINS) Nov 29, 2017 My Background Astronomer / Optical scientist at University of Arizona and Subaru Telescope (National Astronomical Observatory of Japan, Telescope located in Hawaii) I develop instrumentation to find and study exoplanet, for ground-based telescopes and space missions My interest is focused on habitable planets and search for life outside our solar system At Subaru Telescope, I lead the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument. 2 ALL known Planets until 1989 Approximately 10% of stars have a potentially habitable planet 200 billion stars in our galaxy → approximately 20 billion habitable planets Imagine 200 explorers, each spending 20s on each habitable planet, 24hr a day, 7 days a week. It would take >60yr to explore all habitable planets in our galaxy alone. x 100,000,000,000 galaxies in the observable universe Habitable planets Potentially habitable planet : – Planet mass sufficiently large to retain atmosphere, but sufficiently low to avoid becoming gaseous giant – Planet distance to star allows surface temperature suitable for liquid water (habitable zone) Habitable zone = zone within which Earth-like planet could harbor life Location of habitable zone is function of star luminosity L. For constant stellar flux, distance to star scales as L1/2 Examples: Sun → habitable zone is at ~1 AU Rigel (B type star) Proxima Centauri (M type star) Habitable planets Potentially habitable planet : – Planet mass sufficiently large to retain atmosphere, but sufficiently low to avoid becoming gaseous giant – Planet distance to star allows surface temperature suitable for liquid water (habitable zone) Habitable zone = zone within which Earth-like planet could harbor life Location of habitable zone is function of star luminosity L.
    [Show full text]
  • Introduction to High Contrast Imaging
    Observing Exoplanets with High contrast imaging techniques nulling interferometry & coronagraphy High contrast imaging science and challenges Exoplanets – Exoplanet types: Giants, rocky planets – Contrast ratio, Angular separation: why is it difficult ? – Visible vs. Infrared – Complementarities between direct imaging and indirect techniques – Life finding Disks – Planetary formation – Debris disks Brief introduction to approaches to the high contrast imaging challenge – Why don't normal telescopes work for high contrast imaging ? – Coronagraphy – Nulling interferometry – Ground vs. space Exoplanet discoveries New but very active research topic Most planets are discovered with indirect techniques → limited ability to characterize them, and strong need for direct imaging to learn more about the planets and their environments Exoplanet discoveries Techniques to detect exoplanets around main sequence stars (many of them covered in this course): Radial velocity: measure small shift in star's spectra to compute its speed along line of sight. Astrometry: measure accurate position of star on sky to identify if a planet is pulling the star in a small periodic orbit around the center of mass Transit photometry: if planet passes in front of its star, the star apparent luminosity is reduced Microlensing: planet can bend light, and amplify background starlight through gravitational lensing Direct imaging (with telescope or interferometer): capture high contrast image of the immediate surrounding of a star Habitable planets Potentially habitable planet : – Planet mass sufficiently large to retain atmosphere, but sufficiently low to avoid becoming gaseous giant – Planet distance to star allows surface temperature suitable for liquid water (habitable zone) Habitable zone = zone within which Earth-like planet could harbor life Location of habitable zone is function of star luminosity L.
    [Show full text]
  • Florian Rodler (ESO) Introduction
    Exoplanets Florian Rodler (ESO) Introduction The first exoplanet was discovered in 1995. Florian Rodler - ESO La Silla Observing School Introduction The first exoplanet was discovered in 1995. WRONG ✗ Florian Rodler - ESO La Silla Observing School Early beginnings First alleged exoplanets were reported in the 1940s ... (Strand, 1944, AJ, 51, 12) ✗ Florian Rodler - ESO La Silla Observing School Early beginnings The observational concepts were laid out that ~40 years later led to exoplanet discoveries ... (Struwe, 1952, Obs, 72, 199) Florian Rodler - ESO La Silla Observing School Early beginnings Early claims of exoplanet discoveries (with astrometry): (van de Kamp, 1982, Vistas in Ast., 26, 141) ✗ Florian Rodler - ESO La Silla Observing School Exoplanets found, but not claimed 1988: γ Cep b Campbell, Walker &Yang (ApJ 331, 902) Radial velocities ⇒ no firm discovery claim “Probable third-body variation of 25 m s-1 amplitude, 2.7 yr period” ⇒ in 2003 confirmed by Hatzes et al. (ApJ 599, 1383) ✓ 1989: HD114762b Latham et al. (Nature 339, 38) Radial velocities ⇒ no firm discovery claim “The unseen companion of HD114762 - A probable brown dwarf” ... P = 84 d, m ≥ 11 MJupiter ✓ Florian Rodler - ESO La Silla Observing School Planets around Pulsars 1991: PSR 1829-10 Lyne (Nature 352, 537) Pulsar Timing: Radio pulses arrive earlier and later at Earth time Problem: P = ½ yr ⇒ Error in the correction of the eccentricity of the Earth’s movement. ✗ Florian Rodler - ESO La Silla Observing School Planets around Pulsars 1992: PSR 1257+12 Wolszczan & Frail (Nature
    [Show full text]
  • Planets and Exoplanets
    NASE Publications Planets and exoplanets Planets and exoplanets Rosa M. Ros, Hans Deeg International Astronomical Union, Technical University of Catalonia (Spain), Instituto de Astrofísica de Canarias and University of La Laguna (Spain) Summary This workshop provides a series of activities to compare the many observed properties (such as size, distances, orbital speeds and escape velocities) of the planets in our Solar System. Each section provides context to various planetary data tables by providing demonstrations or calculations to contrast the properties of the planets, giving the students a concrete sense for what the data mean. At present, several methods are used to find exoplanets, more or less indirectly. It has been possible to detect nearly 4000 planets, and about 500 systems with multiple planets. Objetives - Understand what the numerical values in the Solar Sytem summary data table mean. - Understand the main characteristics of extrasolar planetary systems by comparing their properties to the orbital system of Jupiter and its Galilean satellites. The Solar System By creating scale models of the Solar System, the students will compare the different planetary parameters. To perform these activities, we will use the data in Table 1. Planets Diameter (km) Distance to Sun (km) Sun 1 392 000 Mercury 4 878 57.9 106 Venus 12 180 108.3 106 Earth 12 756 149.7 106 Marte 6 760 228.1 106 Jupiter 142 800 778.7 106 Saturn 120 000 1 430.1 106 Uranus 50 000 2 876.5 106 Neptune 49 000 4 506.6 106 Table 1: Data of the Solar System bodies In all cases, the main goal of the model is to make the data understandable.
    [Show full text]
  • Searching For, Finding, and Imaging Young Extrasolar Planets with HST
    Searching for, Finding, and Imaging Young Extrasolar Planets with HST/NICMOS 2MASSWJ 1207-334-393254b (2M1207b): A Common Proper Motion Companion of Planetary Mass to a Young Brown Dwarf G. Schneider (Steward Obs., UofA), I. Song, J. Farihi, (Gemini Obs.), B. Zuckerman, E. Becklin (UCLA), P. Lowrance (Caltech), B. Macintosh (LLNL), M. Bessell (ANU) ABSTRACT: Imaging discovery and subsequent characterization of extrasolar planet NICMOS CORONAGRAPHY DETECTION LIMITS & UNCERTAINTIES (EP) mass companions to stars has been observationally challenging due to the severe planet-to-star contrast ratios. Since the detection of the extrasolar giant planet (EGP) The ability to detect faint point sources near bright objects (e.g., planetary mass SINGLE ORBIT observations which roll the telescope about the target axis companion to 51 Peg [1], continuing discoveries of 1 – 10 Jupiter mass companions by companions to stars) is instrumentally enhanced by reducing the brightness of the (unfortunately, technically unfeasible with HST's soon to be implemented two-gyro indirect methods have revealed an unanticipated diversity in mass ranges, dynamical central star. To enable such observations, HST has provided unique resources for high guiding mode) are highly efficient and permit optimal self-subtraction of the properties, and primary-star characteristics. The past decade has seen an explosion of contrast imaging with its panchromatic complement of coronagraphically augmented underlying coronagraphic point-spread function. Such observations yield total indirect detections of EGP companions to solar-like stars through radial velocity imagers: NICMOS (near-IR), ACS (UV/Optical) and, until recently, STIS (broadband integration times of, typically, ~ 1300s. Highly repeatable point source detection limits surveys [2] and more recently, in much smaller numbers, via photometric transits [e.g., Optical).
    [Show full text]
  • THE DISTANCE to the YOUNG EXOPLANET 2M1207 B in the TW HYA ASSOCIATION. E. E. Mamajek, Harvard- Smithsonian Center for Astrophys
    Protostars and Planets V 2005 8522.pdf THE DISTANCE TO THE YOUNG EXOPLANET 2M1207 B IN THE TW HYA ASSOCIATION. E. E. Mamajek, Harvard- Smithsonian Center for Astrophysics, 60 Garden St., MS-42, Cambridge MA 02138, USA, ([email protected]). Introduction: Results: Recently, a faint companion to the young brown dwarf ² The proper motion and radial velocity of 2M1207 are statisti- 2MASSW J1207334-393254 (2M1207) was imaged [1], and cally consistent with TWAmembership (quantitatively strength- found to have common proper motion with its primary [2]. ening claims by [1,4]). The brown dwarf and companion are purported to be members ² The moving cluster method predicts a distance of 53 § 6 pc of the »10 Myr-old TW Hya Association (TWA) [3,4]. As- to the 2M1207 system. suming a distance of 70 § 20 pc and age of 10 Myr, the brown ² The improved distance roughly halves the previously cal- dwarf and companion are consistent with masses of »25 MJup culated luminosities for 2M1207 A and B, and reduces their » » and »5 MJup [1]. There is currently little constraint on the inferred masses to 21 MJup and 3 MJup using modern distance to this astrophysically interesting system (with the evolutionary tracks [9]. The current projected separation be- secondary possibly being the first imaged extrasolar planet). tween A and B is 41 § 5 AU. Although a trigonometric parallax is not yet available, it is pos- ² Objects in the literature with the “TWA” acronym seem to sible to use the proper motion and putative cluster membership be segregated by distance into at least two groups, with TWA of the 2M1207 system to estimate the distance using the mov- 12, 17, 18, 19, 24 appearing to be more distant (d ' 100- ing cluster method.
    [Show full text]
  • A Moving Cluster Distance to the Exoplanet 2M1207 B in the TW Hya
    accepted to Astrophysical Journal, 18 July 2005 A Moving Cluster Distance to the Exoplanet 2M1207 B in the TW Hya Association Eric E. Mamajek1 Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-42, Cambridge, MA 02138 [email protected] ABSTRACT A candidate extrasolar planet companion to the young brown dwarf 2MASSW J1207334-393254 (2M1207) was recently discovered by Chauvin et al. They find that 2M1207 B’s temperature and luminosity are consistent with being a young, ∼5 MJup planet. The 2M1207 system is purported to be a member of the TW Hya association (TWA), and situated ∼70 pc away. Using a revised space mo- tion vector for TWA, and improved proper motion for 2M1207, I use the moving cluster method to estimate the distance to the 2M1207 system and other TWA members. The derived distance for 2M1207 (53 ± 6 pc) forces the brown dwarf and planet to be half as luminous as previously thought. The inferred masses for 2M 1207 A and B decrease to ∼21 MJup and ∼3-4MJup, respectively, with the mass of B being well below the observed tip of the planetary mass function and the theoretical deuterium-burning limit. After removing probable Lower arXiv:astro-ph/0507416v1 18 Jul 2005 Centaurus-Crux (LCC) members from the TWA sample, as well as the prob- able non-member TWA 22, the remaining TWA members are found to have distances of 49 ± 3 (s.e.m.) ± 12(1σ) pc, and an internal 1D velocity dispersion of +0.3 −1 0.8−0.2 km s . There is weak evidence that the TWA is expanding, and the data are consistent with a lower limit on the expansion age of 10 Myr (95% confidence).
    [Show full text]
  • Imaging Young Jupiters Down to the Snowline A
    SPHERE+: Imaging young Jupiters down to the snowline A. Boccaletti, G. Chauvin, D. Mouillet, O. Absil, F. Allard, S. Antoniucci, J.-C. Augereau, P. Barge, A. Baruffolo, J.-L. Baudino, et al. To cite this version: A. Boccaletti, G. Chauvin, D. Mouillet, O. Absil, F. Allard, et al.. SPHERE+: Imaging young Jupiters down to the snowline. 2020. hal-03020449 HAL Id: hal-03020449 https://hal.archives-ouvertes.fr/hal-03020449 Preprint submitted on 13 Dec 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. SPHERE+ Imaging young Jupiters down to the snowline White book submitted to ESO, Feb. 2020 A. Boccaletti1, G. Chauvin2, D. Mouillet2, O. Absil3, F. Allard4, S. Antoniucci5, J.-C. Augereau2, P. Barge6, A. Baruffolo7, J.-L. Baudino8, P. Baudoz1, M. Beaulieu9, M. Benisty2, J.-L. Beuzit6, A. Bianco10, B. Biller11, B. Bonavita11, M. Bonnefoy2, S. Bos15, J.-C. Bouret6, W. Brandner12, N. Buchschache13, B. Carry9, F. Cantalloube12, E. Cascone14, A. Carlotti2, B. Charnay1, A. Chiavassa9, E. Choquet6, Y. Clenet´ 1, A. Crida9, J. De Boer15, V. De Caprio14, S. Desidera7, J.-M. Desert16, J.-B. Delisle13, P. Delorme2, K. Dohlen6, D.
    [Show full text]