Caballero identified the star 2MASS 19281982-2640123 as a potential Sun-like star from which the WOW! signal could have originated. We conducted a search for artificial narrowband (2.79 Hz/1.91 Hz), drifting (±4 Hz s−1) technosignatures from this source using the turboSETI pipeline, from 1–2 GHz, using simultaneous multi-telescope observations with both the Robert C. Byrd Green Bank Telescope and the newly refurbished Allen Telescope Array on 2022 May 21. Both telescope observations had an overlap of 580 s. While blind searches using radio telescopes have been conducted in the general field of view in which the WOW! signal was first detected, this is the first time a targeted search has been done. No technosignature candidates were detected.
The American Astronomical Society (AAS), established in 1899 and based in Washington, DC, is the major organization of professional astronomers in North America. Its membership of about 7,000 individuals also includes physicists, mathematicians, geologists, engineers, and others whose research and educational interests lie within the broad spectrum of subjects comprising contemporary astronomy. The mission of the AAS is to enhance and share humanity's scientific understanding of the universe.
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ISSN: 2515-5172
Research Notes of the AAS is a non-peer reviewed, indexed and secure record of works in progress, comments and clarifications, null results, or timely reports of observations in astronomy and astrophysics.
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Karen I. Perez et al 2022 Res. Notes AAS 6 197
A. Loeb et al 2024 Res. Notes AAS 8 39
We have conducted an extensive towed-magnetic-sled survey during the period 2023 June 14–28, over the seafloor about 85 km north of Manus Island, Papua New Guinea, centered around the calculated path of the bolide CNEOS 2014 January 8 (IM1). We found about 850 spherules of diameter 0.05–1.3 mm in our samples. They were analyzed by microXRF, Electron Probe Microanalyzer and ICP Mass spectrometry. We identified 22% of the spherules as the product of planetary igneous differentiation and labeled them as D-type spherules. A small portion of the D-spherules show an excess of Be, La and U, by up to three orders of magnitude relative to the solar system standard of CI chondrites, and a composition pattern that is distinctly different from coal fly ash.
Sanja Lazarević et al 2024 Res. Notes AAS 8 107
We report the Australian Square Kilometre Array Pathfinder discovery of a new Galactic supernova remnant (SNR) candidate G308.73+1.38, which we name Raspberry. This new SNR candidate has an angular size of 207 × 167, and we measure a total integrated flux of 407 ± 50 mJy. We estimate Raspberry's most likely diameter of 10–30 pc which would place it at a distance 3–5 kpc, in the near side of the Milky Way's Scutum–Centaurus Arm. We also find a Stokes-V point source close to the center of Raspberry with a ∼5σ significance. This point source may be the remaining compact source, a neutron star, or possibly a pulsar, formed during the initial supernova event.
Julie Moquin et al 2024 Res. Notes AAS 8 138
Magnetic reconnection is the underlying cause of stellar flares which are linked to regions of high magnetic activity, like star spots. To understand trends in stellar activity, we need to study how it is heightened by rapid rotation and deep convection in young low-mass stars. We analyze light curves of such stars observed by the Transiting Exoplanet Survey Satellite to investigate trends in flare timing with starspot modulation signals. Trends in flare properties and spot modulation can provide a means to "localize" which face of a star flares more frequently and better understand their association with active regions. We present an analysis of light curves from M and K dwarfs with no companions from five nearby and young moving groups spanning ages ∼20–150 Myr. We discuss a technique to analyze the distribution of flares and star spots and describe our results, which reveal a tentative correlation.
Sangeeta Kumar and Maïssa Salama 2024 Res. Notes AAS 8 123
We present mass estimates and companion demographics on stellar multiples within 25 pc, using a survey of stars of all spectral types done by Robo-AO and supplemented by Gaia. The survey combined direct imaging by Robo-AO, a robotic adaptive optics instrument for 2 m class telescopes, to detect tight companions (<4'' separation) and with Gaia astrometry to detect wider co-moving companions. We estimated the masses for 267 companions using empirical relations and, for a subset of 97, dynamical mass estimates. We utilized previous mass–magnitude models using contrasts measured from Gaia and Robo-AO to estimate the mass and also used the orvara python package, a Markov Chain Monte Carlo orbit fitter using the companion astrometry and Hipparcos-Gaia proper motion accelerations, to estimate dynamical masses. We compare agreements and discrepancies in mass estimates from these two methods.
Carmen Choza et al 2024 Res. Notes AAS 8 37
We describe archival observations and analysis of the HD 110067 planetary system using the Green Bank Telescope (GBT) as part of the Breakthrough Listen search for technosignatures. The star hosts six sub-Neptune planets in resonant orbits, and we tune the drift rate range of our search to match the properties of the system derived by Luque et al. Our observations cover frequencies from 1 to 11.2 GHz, using the GBT's L, S, C, and X-band receivers, to an equivalent isotropic radiated power limit of ∼3 × 1012 W. No technosignatures were found, but this unusual system remains an interesting target for future technosignature searches.
John E. Moores et al 2024 Res. Notes AAS 8 120
A complete understanding of methane in the atmosphere of Mars requires information on putative sources. Organic carbon derived from meteoritic sources, such as interplanetary dust particles (IDPs), over geologic time is the best-defined source of organic carbon on the surface of Mars. Here we examine two different mechanisms for degrading this material to produce methane (1) Ultraviolet photolysis and (2) thermal decomposition. Neither of these mechanisms can produce sufficient methane under realistic assumptions to explain observed methane at Gale Crater, suggesting that IDPs are not the primary source material producing methane on Mars.
Efrain Alvarado III et al 2024 Res. Notes AAS 8 134
The atmospheres of Ultracool Dwarfs (UCDs) are dominated by molecular chemistry, which makes their spectra and photometry particularly sensitive to elemental abundances. With lifespans in excess of the age of the universe, UCDs serve as chemical tracers in every component of the Milky Way. In this study, we present the Spectral ANalog of Dwarfs (SAND) grid of low-temperature model atmospheres that span Teff from 700 to 4000 K, from 4.0 to 6.0, [Fe/H] from −2.4 to +0.3, and a range of [α/Fe] that matches the Galactic distribution inferred from earlier spectroscopic surveys. The SAND grid primarily aims to model the spectra of brown dwarfs in the halo and thick disk of the Milky Way, and metal-poor UCDs in globular clusters.
Lewis Ballard et al 2024 Res. Notes AAS 8 127
SMC3 and Lin358 are super-soft X-ray sources (SSS) in symbiotics of the Small Magellanic Cloud. They have been observed as SSS for over 30 yr. We present new observations done in 2014, 2021 and in 2023 with XMM-Newton, NICER, and Chandra. Lin358 is modeled with an effective temperature around 200,000 K, and a maximum flux value around 8.25 × 10−13 erg cm−2 s−1 in 2021. An observation close to periastron revealed hardening of the source. SMC3 is known to undergo an X-ray obscuration approximately every 4.5 yr; we measured the peak X-ray flux of 4.12 × 10−13 in 2014 with the Chandra Low Energy Transmission Grating. Models indicate an effective temperature of about 500,000 K, consistent with previous findings, and increasing luminosity excursion between maxima and minima. We suggest that with such high effective temperature, indicative of steady shell burning, the possibility these systems are on the path to type Ia supernova is worth considering.
Marcel Drechsler et al 2023 Res. Notes AAS 7 1
We report the discovery of a broad, 15 long filamentary [O iii] emission nebulosity some 12 southeast of the M31 nucleus. This nebulosity is not detected in Hα and has no obvious emission counterparts in X-ray, UV, optical, infrared, and radio surveys. To our knowledge, this emission feature has not been previously reported in the literature. We briefly discuss its possible origin.
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Thayne Currie 2024 Res. Notes AAS 8 146
Recently, Biddle et al. claimed a non-detection of the protoplanet AB Aurigae b in Keck/NIRC2 Paβ imaging. I reprocess these newly public data and compare them to data from the extreme AO platform (SCExAO/CHARIS) used to discover AB Aur b. AB Aur b is decisively imaged with SCExAO/CHARIS at wavelengths covering Paβ. The Biddle et al. non detection of AB Aur b results from a far poorer image quality that is non competitive with SCExAO/CHARIS. Their contrast limits and thus constraints on accretion are overestimated due to an inaccurate AB Aur b source model. Irrespective of image quality, single-band Paβ imaging is ill suited to conclusively identify accretion onto AB Aur b. Instead, high-resolution Hα spectroscopy may provide accretion signatures. Aside from PDS 70, AB Aurigae remains the system with the strongest evidence for having a directly imaged protoplanet.
Bryanne McDonough and Reuben Dsouza 2024 Res. Notes AAS 8 148
An important test of the Λ Cold Dark Matter model is the degree to which galaxy dark matter halos follow the predicted, characteristic density profile. In this Note, we explore the use of satellite galaxies as luminous tracers of halo mass density profiles as a function of the time since they joined the halos. We perform this investigation in the TNG100 simulation, where we can obtain precise locations of satellite galaxies and dark matter particles. We find that, by adopting a more accurate definition of joining redshift compared to a previous investigation, the oldest satellites are better, but not perfect tracers of the dark matter distribution.
Roméo Veyry and Richard Monier 2024 Res. Notes AAS 8 147
High resolution high signal-to-noise UVES spectra of the late B-type chemically peculiar star, HD 87240, a member of the NGC 3114 open cluster, have been synthesized to measure the abundance of chlorine, an element which is rarely found in late B-type stars. Sixteen lines of Cl ii are found and the mean chlorine overabundance is about 2.1 dex higher than the solar abundance, which is slightly lower than the chlorine excess in HR 1094, another chlorine-rich late B-type star.
Tongtian Ren et al 2024 Res. Notes AAS 8 145
Project Hephaistos recently identified seven M-dwarfs as possible Dyson Spheres (DS) candidates. We have cross-matched three of these candidates (A, B and G) with radio sources detected in various all-sky surveys. The radio sources are offset from the Gaia stellar positions by ∼4.9, ∼0.4 and ∼50 for candidates A, B, and G respectively. We propose that Dust obscured galaxies (DOGs) lying close to the line-of-sight of these M-dwarf stars significantly contribute to the measured WISE mid-IR flux densities in the WISE W3 and W4 wave bands. These three stars have therefore been misidentified as DS candidates. We also note that with an areal sky density of 9 × 10−6 per square arcsecond, Hot DOGs can probably account for the contamination of all 7 DS candidates drawn from an original sample of 5 million stars.
Naga Varun Yelagandula 2024 Res. Notes AAS 8 142
This is to address the criticism expressed in the article (Goedbloed & Poedts 2024) referred to as GP[24] about the work (Yelagandula 2023) referred to as Y[23]. It will be shown that the dispersion relation obtained in Y[23] is indeed correct within the framework of the ZSER model discussed in Y[23] despite the correct criticism of GP[24] about the electrodynamic boundary condition.