Updated orbital monitoring and dynamical masses for nearby M-dwarf binaries

Abstract

Young M-type binaries are particularly useful for precise isochronal dating by taking advantage of their extended pre-main sequence evolution. Orbital monitoring of these low-mass objects becomes essential in constraining their fundamental properties, as dynamical masses can be extracted from their Keplerian motion. Here, we present the combined efforts of the AstraLux Large Multiplicity Survey, together with a filler sub-programme from the SpHere INfrared Exoplanet (SHINE) project and previously unpublished data from the FastCam lucky imaging camera at the Nordical Optical Telescope (NOT) and the NaCo instrument at the Very Large Telescope (VLT). Building on previous work, we use archival and new astrometric data to constrain orbital parameters for 20 M-type binaries. We identify that eight of the binaries have strong Bayesian probabilities and belong to known young moving groups (YMGs). We provide a first attempt at constraining orbital parameters for 14 of the binaries in our sample, with the remaining six having previously fitted orbits for which we provide additional astrometric data and updated Gaia parallaxes. The substantial orbital information built up here for four of the binaries allows for direct comparison between individual dynamical masses and theoretical masses from stellar evolutionary model isochrones, with an additional three binary systems with tentative individual dynamical mass estimates likely to be improved in the near future. We attained an overall agreement between the dynamical masses and the theoretical masses from the isochrones based on the assumed YMG age of the respective binary pair. The two systems with the best orbital constrains for which we obtained individual dynamical masses, J0728 and J2317, display higher dynamical masses than predicted by evolutionary models.

Speckle Interferometry at SOAR Telescope in 2023

“…05321−0305 (V1311 Ori) is a system of pre-main-sequence M-type dwarfs containing at least six stars (Tokovinin 2022). The updated 150 yr orbit of Aa,Ab uses measures near the periastron recently published by Calissendorff et al (2022) and the latest SOAR data, but it will remain loosely constrained until the binary approaches the apastron in a few decades. On the other hand, the tentative 8 yr orbit of the faster pair Ba,Bb discovered at SOAR in 2021 will become well defined in the next few years.…”

Direct Imaging Explorations for Companions around Mid–Late M Stars from the Subaru/IRD Strategic Program

“…Figure 7 shows a mass ratio (q) versus separation diagram of the resolved companions in our study compared with previous imaging studies and a histogram of the mass ratio. Note that the mass range of the primary star is different in each study: Calissendorff et al (2022), and M pri ∼ 0.5-0.6 M e in Biller et al (2022). As suggested in Reggiani & Meyer (2011), the mass ratios of the companions detected from our observations show consistency in the empirical mass ratio of M-type binary systems (e.g., peak at q = 0.63-1; Fischer & Marcy 1992) rather than the initial mass function for a single M-type star (peak at Note.…”

“…Since the systems are all nearby (∼10-30 pc) and the semimajor axes appear to be quite small (for example, LSPM J0825+6902, LSPM J1645+0444, and LSPM J2204 +1505 all have companions whose projected separations are close to 2-3 au), they are good candidates for obtaining both individual brightnesses and individual dynamical masses for each stellar component. Such system types remain rare, but they are important for calibrating evolutionary and isochronal models in the low-mass stellar regime (e.g., Calissendorff et al 2022).…”

“…From an observational viewpoint, unresolved binarity can lead to systematic errors or uncertainties in the measured properties of stars and planets (e.g., Daemgen et al 2009;Kopytova et al 2016). Conversely, a well-characterized stellar binary provides useful astrophysical information that would otherwise be difficult to attain, such as the dynamical masses of stars (e.g., Montet et al 2015;Calissendorff et al 2022). Simultaneous knowledge of both the brightness and the dynamical mass of stars is especially important for constraining isochronal and evolutionary models (e.g., Baraffe et al 1998;Feiden 2016), which remain uncertain, particularly for active M-type stars (e.g., Pecaut & Mamajek 2016;Janson et al 2018;Asensio-Torres et al 2019).…”

Detecting New Visual Binaries in Gaia DR3 with Gaia and Two Micron All Sky Survey (2MASS) Photometry. I. New Candidate Binaries within 200 pc of the Sun

“…Citation flags correspond to following studies: (1)Worley (1972), (2)Heintz (1975), (3)Heintz (1980), (4)Couteau (1982), (5)Couteau (1985), (6) McAlister et al (1987), (7) Heintz (1987), (8) Couteau et al (1993), (9) Hartkopf et al (1993), (10) Couteau & Gili (1994), (11) Poveda et al (1994), (12) Al-Shukri et al (1996), (13) Gili & Couteau (1997), (14) Fu et al (1997), (15) Heintz (1998), (16) Morlet et al (2000), (17) McCarthy et al (2001), (18) Fabricius et al (2002), (19) Strigachev & Lampens (2004), (20) Hartkopf et al (2008), (21) Docobo et al (2008), (22) Law et al (2008), (23) Hartkopf & Mason (2009), (24) Bergfors et al (2010), (25) Tokovinin et al (2010), (26) Raghavan et al (2010), (27) Orlov et al (2010), (28) Horch et al (2011), (29) Mason et al (2011), (30) Orlov et al (2011), (31) Horch et al (2012), (32) Hartkopf et al (2012), (33) Janson et al (2012), (34) Ginski et al (2012), (35) Mason et al (2013), (36) Jódar et al (2013), (37) Janson et al (2014), (38) Horch et al (2015b), (39) Tokovinin et al (2015), (40) Horch et al (2015a), (41) Ward-Duong et al (2015), (42) Gomez et al (2016), (43) Janson et al (2017), (44) Horch et al (2017), (45) Halbwachs et al (2018), (46) Mason et al (2018), (47) Kervella et al (2019), (48) Matson et al (2019), (49) Winters et al (2019), (50) Tokovinin et al (2019), (51) Bowler et al (2019), (52) Docobo et al (2019), (53) Lamman et al (2020), (54) Horch et al (2020), (55) Tokovinin et al (2020), (56) Jönsson et al (2020), (57) Vrijmoet et al (2020), (58) Horch et al (2021), (59) Mason et al (2021), (60) Salama et al (2021), (61) Mitrofanova et al (2021), (62) Brandt (2021), (63) Calissendorff et al (2022), (64) Vrijmoet et al (2022), (65) Salama et al (2022), and (66) Whiting et al (2023).…”