J/AJ/168/143 Haro 5-2: new pre-MS quadruple stellar system (Reipurth+, 2024)
Haro 5-2: a new pre-main-sequence quadruple stellar system.
Reipurth B., Briceno C., Geballe T.R., Baranec C., Mikkola S., Cody A.M.,
Connelley M.S., Flores C., Skiff B.A., Armstrong J.D., Law N.M.,
Riddle R.
<Astron. J., 168, 143 (2024)>
=2024AJ....168..143R 2024AJ....168..143R
ADC_Keywords: Stars, pre-main sequence ; Stars, double and multiple ;
Spectra, infrared ; Optical ; Spectroscopy
Keywords: Pre-main sequence stars ; Binary stars ; Multiple stars ;
T Tauri stars ; Young stellar objects
Abstract:
We have discovered that the Hα emission-line star Haro 5-2,
located in the 3-6Myr old Ori OB1b association, is a young quadruple
system. The system has a 2+2 configuration, with an outer separation
of 2.6" and with resolved subarcsecond inner binary components. The
brightest component, Aa, dominates the A-binary; it is a weak-line T
Tauri star with spectral type M2.5±1. The two stars of the B
component are equally bright at J, but the Bb star is much redder.
Optical spectroscopy of the combined B pair indicates a rich
emission-line spectrum with a M3±1 spectral type. The spectrum is
highly variable and switches back and forth between a classical and a
weak-line T Tauri star. In the near-IR, the spectrum shows Paschen
β and Brackett γ in emission, indicative of active
accretion. A significant mid-IR excess reveals the presence of
circumstellar or circumbinary material in the system. Most multiple
systems are likely formed during the protostellar phase, involving
flybys of neighboring stars followed by an inspiraling phase driven by
accretion from circumbinary material and leading to compact
subsystems. However, Haro 5-2 stands out among young 2+2 quadruples,
as the two inner binaries are unusually wide relative to the
separation of the A and B pair, allowing future studies of the
individual components. Assuming the components are coeval, the system
could potentially allow stringent tests of pre-main-sequence
evolutionary models.
Description:
We observed the pre-main-sequence quadruple stellar system Haro 5-2,
with the NIRC2 instrument behind the Keck II adaptive optics system on
UT 2015 August 5. We obtained six 30s exposures with the Kp filter and
then five 30s exposures with the H filter.
Direct images of Haro 5-2 were obtained on UT 2015 August 27 at the
Gemini-North telescope with NIRI with adaptive optics. In the J and H
bands, a 3x3 mosaic was obtained with individual 3s exposures, in
total 81s, while in the K band the exposures totaled 162s.
Haro 5-2 was observed with GNIRS at the Gemini-North telescope on UT
2015 September 15. The two components could be resolved at H and K,
but not at J, and separate spectra were extracted in H and K.
We obtained spectroscopy of the Haro A and B components, separated by
2.62", with the Goodman High Throughput Spectrograph (GHTS) (Low
resolution: wavelength range ∼3600≲λ≲9000Å, R=830.
High-resolution: from 6140Å to 6705Å, R=11930) , installed on
the SOAR 4.1m telescope on Cerro Pachon, Chile. We used available
time slots during the engineering nights of 2021 October 19 and
November 18, 2022 November 9, and 2023 January 6 and March 9, for a
total time span of about 1.4yr.
On the same nights that we obtained optical spectra on SOAR, we also
obtained near-IR spectroscopy resolving the Haro 5-2A and B components
using the TripleSpec 4.1 (TSpec) near-IR spectrograph. The spectral
resolution is R ∼3500 across the six science orders.
Haro 5-2 was observed by TESS in its sector 6 (2018 December 11 to
2019 January 7) and sector 32 (2020 November 19 to 2020 December 17)
campaigns, which lasted approximately 27 days each.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
05 35 07.53 -02 48 59.6 Haro 5-2 = TIC 427380741
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 99 24 SOAR Goodman optical GHTS observations of Haro 5-2
table2.dat 83 10 Equivalent Widths in SOAR low-resolution spectra of
Haro 5-2
fig8.dat 72 8 List of SOAR TripleSpec NIR spectra
fig9a.dat 22 701 H-band spectra of the individual Ba component
resolved with adaptive optics and GNIRS at the
Gemini-North 8m telescope
fig9b.dat 22 701 H-band spectra of the individual Bb component
resolved with adaptive optics and GNIRS at the
Gemini-North 8m telescope
sp/* . 14 SOAR GHTS and TripleSpec spectra in FITS format
(Data behind Figure 4, 5 and 8)
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2020)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
J/AJ/106/1059 : Lithium in the Pleiades (Soderblom+, 1993)
J/A+A/478/667 : The Mayrit catalogue (Caballero, 2008)
J/A+A/485/931 : Young stars and brown dwarfs in Ori OB1b (Caballero+, 2008)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/A+A/526/A21 : Collinder 69 X-ray sources (Barrado+, 2011)
J/PASJ/63/S1 : Atlas & catalog 2MASS dark clouds (Dobashi+, 2011)
J/A+A/527/A24 : Spectra of low-mass stars in Upper Sco (Lodieu+, 2011)
J/AJ/146/85 : Spectral types of optical stars in ONC (Hillenbrand+, 2013)
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/ApJ/786/97 : Photospheric properties of T Tauri stars (Herczeg+, 2014)
J/ApJ/794/36 : σ Orionis cluster star population (Hernandez+, 2014)
J/A+A/570/A30 : Hα emission-line stars in M42 (Pettersson+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/AJ/147/87 : Binaries to multiples II. Statistical data (Tokovinin, 2014)
J/AJ/150/100 : WISE YSO candidates, σ & λ Ori (Koenig+, 2015)
J/ApJ/799/4 : Robo-AO observations of binary stars (Riddle+, 2015)
J/AJ/152/213 : Interferometry & spectroscopy: σ Ori (Schaefer+, 2016)
J/MNRAS/469/3881 : Embedded binaries and their dense cores (Sadavoy+, 2017)
J/AJ/154/14 : Low-mass stars in 25 Ori group & Orion OB1a (Suarez+, 2017)
J/AJ/156/84 : APOGEE-2 survey of Orion Complex. II. (Kounkel+, 2018)
J/AJ/157/85 : The CIDA Variab. Survey of Orion OB1. II. (Briceno+, 2019)
J/AJ/158/95 : V348 And & V572 Per: heliocentric min & RVs (Zasche+, 2019)
J/ApJ/925/21 : IRTF/iSHELL K-band sp. obs. of PMS stars (Flores+, 2022)
J/ApJS/259/66 : Eclipsing quadruple star candidates: TESS (Kostov+, 2022)
J/AJ/164/58 : Speckle Interferometry at SOAR in 2021 (Tokovinin+, 2022)
J/A+A/682/A164 : Double eclipsing binaries from ZTF (Vaessen+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Comp [AB] Haro 5-2 Component
3- 12 A10 "Y/M/D" Date Date of observation (UT)
14- 21 A8 --- Setup Instrument setup (1)
23- 26 A4 --- Res Resolution ("low" or "high");
column added by CDS for technical purpose (1)
28- 35 A8 arcsec Slit Slit width
37- 41 A5 --- Bin Binning
43 I1 --- Nexp [1/3] Number of exposure
45 A1 --- --- [x]
47- 50 I4 s Exp [120/1200] Exposure time
52- 99 A48 --- File Name of the FITS file in subdirectory "sp";
column added by CDS
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Note (1): We configured the spectrograph for both low- and high-resolution
setups.
For the low-resolution setup, we used the 400l/mm grating in its 400M1
and 400M2+GG 455 filter preset modes, with 2x2 binning. These two
configurations combined span the wavelength range
∼3600≲λ≲9000Å. We used the 1" wide long slit, which yields
an FWHM resolution =6.7Å (equivalent to R=830). We used exposure
times of 120s for the brighter Haro 5-2A and 300s for the fainter
Haro5-2B. A total of 21 low-resolution spectra were obtained for
Haro5-2A (13 in the 400M1 setup and eight with the 400M2 setup), while
25 spectra were obtained for Haro 5-2B (13 with the 400M1 setup and
12 with the 400M2 one).
For the higher-resolution spectra, we used the 2100l/mm grating
centered at 650nm, with the 0.45" long slit, and 1x2 binning. This
setup produces an FWHM resolution of 0.45Å (or R=11930), spanning
565Å, from 6140Å to 6705Å. We took a total of six
higher-resolution spectra for each of the A and B components, three
each on 2021 October 21 and three each on 2021 November 19.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 1 A1 --- Comp [AB] Haro 5-2 Component
3- 6 A4 --- SpT Spectral Type
8- 8 A1 --- TTS [CW] (C)lassical or (W)eak-lined T-Tauri star
10- 19 A10 "Y/M/D" Date UT Observation date
21- 25 F5.1 0.1nm EWHa [-37.5/-3.3] Equivalent Width, Hα
27- 29 F3.1 0.1nm e_EWHa [0.1/2.0] Uncertainty in EWHa
31- 35 F5.1 0.1nm EWHb [-12.0/-1.8] Equivalent Width, Hβ
37- 39 F3.1 0.1nm e_EWHb [0.1/2.0] Uncertainty in EWHb
41- 43 F3.1 0.1nm EWLi [0.2/0.4] Equivalent Width, Li
45- 47 F3.1 0.1nm e_EWLi [0.1/0.1] Uncertainty in EWLi
49- 51 F3.1 0.1nm EWNaI [1.2/1.8]? Equivalent Width, NaI (1)
53- 55 F3.1 0.1nm e_EWNaI [0.1/0.1]? Uncertainty in EWNaI (1)
57- 61 F5.2 0.1nm EWCaII84 [-2.34/0.6]? Equivalent Width, CaII 8498Å
63- 65 F3.1 0.1nm e_EWCaII84 [0.1/0.1]? Uncertainty in EWCaII84
67- 70 F4.1 0.1nm EWCaII85 [-1.6/1.3]? Equivalent Width, CaII 8542Å
72- 74 F3.1 0.1nm e_EWCaII85 [0.1/0.2]? Uncertainty in EWCaII85
76- 79 F4.1 0.1nm EWCaII86 [-1.3/1.0]? Equivalent Width, CaII 8662Å
81- 83 F3.1 0.1nm e_EWCaII86 [0.1/0.1]? Uncertainty in EWCaII86
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Note (1): For the Na I doublet we report the combined equivalent width of
the 8183Å and 8195Å lines.
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Byte-by-byte Description of file: fig8.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Comp [AB] Haro 5-2 Component
3- 12 A10 "Y/M/D" Date Date of observation (UT)
14- 60 A47 --- File Name of the FITS file in subdirectory "sp"
62- 66 F5.3 um lambda1 [0.9/1.9] Lower wavelength range
68- 72 F5.3 um lambda2 [1.2/2.5] Upper wavelength range
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Byte-by-byte Description of file: fig9*.dat
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Bytes Format Units Label Explanations
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1- 8 F8.6 um Wave [1.45/1.8] Wavelength, microns
10- 22 E13.7 W/m2/um Flux [1.6e-15/7.5e-15] Flux
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History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 20-May-2025