J/AJ/162/44 Near-IR spectrum of HIP 109427 with SCExAO/CHARIS (Steiger+, 2021)
SCExAO/MEC and CHARIS Discovery of a Low-mass, 6au Separation Companion to
HIP109427 Using Stochastic Speckle Discrimination and High-contrast Spectroscopy
Steiger S., Currie T., Brandt T.D., Guyon O., Kuzuhara M., Chilcote J.,
Groff T.D., Lozi J., Walter A.B., Fruitwala N., Bailey III J.I., Zobrist N.,
Swimmer N., Lipartito I., Smith J.P., Bockstiegel C., Meeker S.R.,
Coiffard G., Dodkins R., Szypryt P., Davis K.K., Daal M., Bumble B.,
Vievard S., Sahoo A., Deo V., Jovanovic N., Martinache F., Doppmann G.,
Tamura M., Kasdin N.J., Mazin B.A.
<Astron. J., 162, 44 (2021)>
=2021AJ....162...44S 2021AJ....162...44S
ADC_Keywords: Stars, A-type; Exoplanets; Spectra, infrared
Keywords: Direct imaging ; Astronomy data analysis ;
Exoplanet detection methods ; Low mass stars
Abstract:
We report the direct imaging discovery of a low-mass companion to the
nearby accelerating A star, HIP109427, with the Subaru Coronagraphic
Extreme Adaptive Optics (SCExAO) instrument coupled with the Microwave
Kinetic Inductance Detector Exoplanet Camera (MEC) and CHARIS integral
field spectrograph. CHARIS data reduced with reference star point
spread function (PSF) subtraction yield 1.1-2.4µm spectra. MEC
reveals the companion in Y and J band at a comparable signal-to-noise
ratio using stochastic speckle discrimination, with no PSF subtraction
techniques. Combined with complementary follow-up Lp photometry from
Keck/NIRC2, the SCExAO data favors a spectral type, effective
temperature, and luminosity of M4-M5.5, 3000-3200K, and
log10(L/L☉)=-2.28-0.04+0.04, respectively. Relative
astrometry of HIP109427B from SCExAO/CHARIS and Keck/NIRC2, and
complementary Gaia-Hipparcos absolute astrometry of the primary favor
a semimajor axis of 6.55+3.0-0.48au, an eccentricity of
0.54-0.15+0.28, an inclination of 66.7-14+8.5degrees, and a
dynamical mass of 0.280-0.059+0.18M☉. This work shows the
potential for extreme AO systems to utilize speckle statistics in
addition to widely used postprocessing methods to directly image faint
companions to nearby stars near the telescope diffraction limit.
Description:
In three epochs between 2020 July and December, we observed HIP109427
with the Subaru Telescope using the Subaru Coronagraphic Extreme
Adaptive Optics (SCExAO) coupled to the Coronagraphic High Angular
Resolution Imaging Spectrograph (CHARIS) and the Microwave Kinetic
Inductance Detector Exoplanet Camera (MEC) and with the Keck II
telescope using the NIRC2 camera.
MEC data (2020 October 7) covers wavelengths over the Y and J
passbands (0.95-1.4µm) at a spectral resolution of ∼3.3. We
obtained CHARIS data in broadband (1.1-2.4µm; 2020 July 31) at a
resolution of ∼18 or in the H band at a higher resolution (∼70).
Objects:
--------------------------------------------------
RA (2000) DE Designation(s)
--------------------------------------------------
22 10 11.99 +06 11 52.3 HIP 109427 = HIP 109427
--------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
fig3a.dat 35 19 SCExAO/CHARIS spectra for HIP 109427 B from H-band
data
fig3b.dat 35 22 SCExAO/CHARIS spectra for HIP 109427 B extracted
from broadband data
--------------------------------------------------------------------------------
See also:
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
J/AJ/129/2420 : Proper motion derivatives of binaries (Makarov+, 2005)
J/AJ/132/161 : NStars project: The southern sample. I. (Gray+, 2006)
J/MNRAS/389/585 : Fundamental parameters of M dwarfs (Casagrande+, 2008)
J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)
J/MNRAS/437/1216 : VAST Survey. A-type stars multiplicity (De Rosa+, 2014)
J/ApJ/804/146 : Atmospheric parameters for nearby B-F stars (David+, 2015)
J/ApJS/219/33 : BANYAN. VII. Candidate YMG members from BASS (Gagne+, 2015)
J/other/Sci/350.64 : 51 Eri b near-infrared spectrum (Macintosh+, 2015)
J/A+A/605/L9 : NIR spectrum of exoplanet HIP 65426b (Chauvin+, 2017)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/AJ/156/286 : The LEECH exoplanet imaging survey (Stone+, 2018)
J/AJ/158/13 : The first 300 stars observed by the GPIES (Nielsen+, 2019)
Byte-by-byte Description of file: fig3[ab].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.7 um lambda Wavelength
11- 17 F7.4 mJy Flux Flux density
19- 26 F8.5 mJy e_Flux Mean error on flux density
28- 35 F8.5 --- SNR Signal to Noise Ratio
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 15-Nov-2021