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We present the validation of two planets orbiting M dwarfs, TOI-1696b and TOI-2136b. Both planets are mini-Neptunes orbiting nearby stars, making them promising prospects for atmospheric characterization with the James Webb Space Telescope (JWST). We validated the planetary nature of both candidates using high-contrast imaging, ground-based photometry, and near-infrared radial velocities. Adaptive optics images were taken using the ShARCS camera on the 3 m Shane Telescope. Speckle images were taken using the NN-Explore Exoplanet Stellar Speckle Imager on the WIYN 3.5 m telescope. Radii and orbital ephemerides were refined using a combination of the Transiting Exoplanet Survey Satellite, the diffuser-assisted Astrophysical Research Consortium (ARC) Telescope Imaging Camera (ARCTIC) imager on the 3.5 m ARC telescope at Apache Point Observatory, and the 0.6 m telescope at Red Buttes Observatory. We obtained radial velocities using the Habitable-Zone Planet Finder on the 10 m Hobby–Eberly Telescope, which enabled us to place upper limits on the masses of both transiting planets. TOI-1696b (P = 2.5 days; R p = 3.24 R ⊕; M p < 56.6 M ⊕) falls into a sparsely populated region of parameter space considering its host star’s temperature (T eff = 3168 K, M4.5), as planets of its size are quite rare around mid- to late-M dwarfs. On the other hand, TOI-2136b (P = 7.85 days; R p = 2.09 R ⊕; M p < 15.0 M ⊕) is an excellent candidate for atmospheric follow-up with the JWST.

We confirm the planetary nature of TOI-532b, using a combination of precise near-infrared radial velocities with the Habitable-zone Planet Finder, TESS light curves, ground based photometric follow-up, and high-contrast imaging. TOI-532 is a faint (J$\sim 11.5$) metal-rich M dwarf with Teff = $3957\pm69$ K and [Fe/H] = $0.38\pm0.04$; it hosts a transiting gaseous planet with a period of $\sim 2.3$ days. Joint fitting of the radial velocities with the TESS and ground-based transits reveal a planet with radius of $5.82\pm0.19$ R$_{\oplus}$, and a mass of $61.5_{-9.3}^{+9.7}$ M$_{\oplus}$. TOI-532b is the largest and most massive super Neptune detected around an M dwarf with both mass and radius measurements, and it bridges the gap between the Neptune-sized planets and the heavier Jovian planets known to orbit M dwarfs. It also follows the previously noted trend between gas giants and host star metallicity for M dwarf planets. In addition, it is situated at the edge of the Neptune desert in the Radius--Insolation plane, helping place constraints on the mechanisms responsible for sculpting this region of planetary parameter space., 19 pages, 9 figures, 4 tables. arXiv admin note: text overlap with arXiv:2006.14546

We report the discovery of a previously unknown massive Galactic star cluster at l=29.22, b=-0.20. Identified visually in mid-IR images from the Spitzer GLIMPSE survey, the cluster contains at least 8 late-type supergiants, based on followup near-IR spectroscopy, and an additional 3-6 candidate supergiant embers having IR photometry consistent with a similar distance and reddening. The cluster lies at a local minimum in the 13-CO column density and 8 micron emission. We interpret this feature as a hole carved by the energetic winds of the evolving massive stars. The 13-CO hole seen in molecular maps at V_LSR ~95 km/s corresponds to near/far kinematic distances of 6.1/8.7+/-1 kpc. We calculate a mean spectrophotometric distance of 7.0^+3.7_-2.4 kpc, broadly consistent with the kinematic distances inferred. This location places it near the northern end of the Galactic bar. For the mean extinction of A_V=12.6+/-0.5 mag (A_K=1.5+/-0.1 mag), the color-magnitude diagram of probable cluster members is well fit by isochrones in the age range 18-24 Myr. The estimated cluster mass is ~20,000 Msun. With the most massive original cluster stars likely deceased, no strong radio emission is detected in this vicinity. As such, this RSG cluster is representative of adolescent massive Galactic clusters that lie hidden behind many magnitudes of dust obscuration. This cluster joins two similar red supergiant clusters as residents of the volatile region where the end of our Galaxy's bar joins the base of the Scutum-Crux piral arm, suggesting a recent episode of widespread massive star formation there., Comment: 26 pages; Accepted for publication in The Astronomical Journal 2009 March 13; Submitted 2008 November 6. Reports a concurrent discovery of the star cluster investigated by Clark et al. in arXiv:0903.1754

We present the orbital solutions for four OB spectroscopic binaries, MT145, GSC 03161-00815, 2MASS J20294666+4105083, and Schulte 73, and the partial orbital solution to the B spectroscopic binary, MT372, as part of an ongoing study to determine the distribution of orbital parameters for massive binaries in the Cygnus OB2 Association. MT145 is a new, single-lined, moderately eccentric (e=0.291+/-0.009) spectroscopic binary with period of 25.140+/-0.008 days. GSC 03161-00815 is a slightly eccentric (e=0.10+/-0.01), eclipsing, interacting and double-lined spectroscopic binary with a period of 4.674+/-0.004 days. 2MASS J20294666+4105083 is a moderately eccentric (e=0.273+/-0.002) double-lined spectroscopic binary with a period of 2.884+/-0.001 days. Schulte 73 is a slightly eccentric (e=0.169+/-0.009), double-lined spectroscopic binary with a period of 17.28+/-0.03 days and the first "twin" in our survey with a mass ratio of q=0.99+/-0.02. MT372 is a single-lined, eclipsing system with a period of 2.228 days and low eccentricity (e~0). Of the now 18 known OB binaries in Cyg OB2, 14 have periods and mass ratios. Emerging evidence also shows that the distribution of log(P) is flat and consistent with Oepik's Law., Accepted to Astronomical Journal

We report the discovery of a probable new globular cluster in the disk of the Milky Way. Visible in 2MASS and the GLIMPSE survey, it has an estimated foreground extinction of A_V ~ 24 mag. The absolute magnitude of the cluster and the luminosity function of the red giant branch are most consistent with that of an old globular cluster with a mass of a few times 10^5 solar masses at a distance of 4-8 kpc., Comment: 13 pages, submitted to AJ on 10 July 2008

VLA and Parkes 64 m radiotelescope 21-cm observations of the starburst dwarf galaxy NGC 5253 reveal a multi-component non-axisymmetric HI distribution. The component associated with the stellar body shows evidence for a small amount of rotational support aligned with the major axis, in agreement with optically measured kinematics and consistent with the small galaxian mass. Approximately 20-30% of the HI emission is associated with a second component, an HI "plume" extending along the optical minor axis to the southeast. We consider outflow, inflow, and tidal origins for this feature. Outflow appears improbable, inflow is a possibility, and tidal debris is most consistent with the observations. These observations also reveal a filamentary third component that includes an 800 pc diameter HI shell or bubble to the west of the nucleus, coinciding with an Halpha shell. The mass of HI in the shell may be as large as ~4x10^6 Msun. This large mass, coupled with the lack of expansion signatures in the neutral and ionized gas (v, 36 pages, 12 figures; Accepted for Publication in the Astronomical Journal ; a postscript version with high resolution figures can be found at http://physics.uwyo.edu/~chip/Papers/

Arcuate infrared nebulae are ubiquitous throughout the Galactic Plane and are candidates for partial shells, bubbles, or bowshocks produced by massive runaway stars. We tabulate infrared photometry for 709 such objects using images from the Spitzer Space Telescope (SST), Wide-Field Infrared Explorer (WISE), and Herschel Space Observatory (HSO). Of the 709 objects identified at 24 or 22 microns, 422 are detected at the HSO 70 micron bandpass. Of these, only 39 are detected at HSO 160 microns. The 70 micron peak surface brightnesses are 0.5 to 2.5 Jy/square arcminute. Color temperatures calculated from the 24 micron to 70 micron ratios range from 80 K to 400 K. Color temperatures from 70 micron to 160 micron ratios are systematically lower, 40 K to 200 K. Both of these temperature are, on average, 75% higher than the nominal temperatures derived by assuming that dust is in steady-state radiative equilibrium. This may be evidence of stellar wind bowshocks sweeping up and heating --- possibly fragmenting but not destroying --- interstellar dust. Infrared luminosity correlates with standoff distance, R_0, as predicted by published hydrodynamical models. Infrared spectral energy distributions are consistent with interstellar dust exposed to a either single radiant energy density, U=10^3 to 10^5 (in more than half of the objects) or a range of radiant energy densities U_min=25 to U_max=10^3 to 10^5 times the mean interstellar value for the remainder. Hence, the central OB stars dominate the energetics, making these enticing laboratories for testing dust models in constrained radiation environments. SEDs are consistent with PAH fractions q_PAH, Accepted for publication in the Astrophysical Journal

The [O II] λ3727 emission lines and absorption features from stellar Balmer and Ca H and K lines are the most accessible kinematic diagnostics in galaxies at z ~ 1. We investigate the kinematics of 22 local late-type galaxies using these spectral features, and we compare the results with 21 cm neutral hydrogen spectra in order to assess the utility of each diagnostic for measuring galaxy masses. In order to simulate data at high redshift, where only one-dimensional velocity profiles are normally available, we study spatially integrated, as well as spatially resolved, spectra. Although the studied galaxies span a wide range of morphological types, inclinations, and star formation rates, we find that the gaseous and stellar kinematic tracers yield comparable kinematic line widths and systemic velocities. The [O II] and H I line widths correlate most strongly, showing an intrinsic dispersion of ~20 km s-1, or ~10% for a typical galaxy with a kinematic width of 200 km s-1. In a few extreme cases, the [O II] line widths underestimate the neutral hydrogen width by 50%. Reliable velocity widths can also be obtained from the stellar Balmer and Ca H and K absorption lines, even for some of the very late type galaxies that have strong emission lines. The intrinsic dispersion is ≤10% between the stellar absorption and H I line widths. We provide a prescription for using these strong stellar absorption and [O II] emission features to measure the kinematics, and thus masses, of galaxies in the distant universe.

We combine these new observations with data from the literature to form a sample of dwarf galaxies that all have CO observations and measured oxygen abundances. No known galaxies with 12 + log (O/H) 8.1] metallicities are detected at similar or higher ICO surface brightnesses. The data are consistent with a strong dependence of the ICO/M ≡ XCO conversion factor on ambient metallicity. The strikingly low upper limits on some metal-poor galaxies lead us to predict that the conversion factor is nonlinear, increasing sharply below ~1/10 of the solar metallicity [12 + log (O/H) ≤ 7.9].

We present a spectroscopic and photometric determination of the distance to the young Galactic open cluster Westerlund 2 using WFPC2 imaging from the Hubble Space Telescope and ground-based optical spectroscopy. HST imaging in the F336W, F439W, F555W, and F814W filters resolved many sources previously undetected in ground-based observations and yielded photometry for 1136 stars. We identified fifteen new O-type stars, along with two probable binary systems, including MSP 188 (O3 + O5.5). We fit reddened SEDs based on the Padova isochrones to the photometric data to determine individual reddening parameters $R_{V}$ and $A_{V}$ for O-type stars in Wd2. We find average values $\langle R_{V} \rangle = 3.77 \pm 0.09$ and $\langle A_{V} \rangle = 6.51 \pm 0.38$ mag, which result in a smaller distance than most other spectroscopic and photometric studies. After a statistical distance correction accounting for close unresolved binaries (factor of 1.08), our spectroscopic and photometric data on 29 O-type stars yield that Westerlund 2 has a distance $\langle d \rangle = 4.16 \pm 0.07$ (random) $+0.26$ (systematic) kpc. The cluster's age remains poorly constrained, with an upper limit of 3 Myr. Finally, we report evidence of a faint mid-IR PAH ring surrounding the well-known binary candidate MSP~18, which appears to lie at the center of a secondary stellar grouping within Westerlund 2., 58 pages, 20 figures

We present photometry and linear polarimetry of Cygnus X-3 at K (2.2 micrometers) obtained over a 5 yr period. Photometry and polarimetry at J, H, and K of nearby field stars is also presented. From an analysis of these data we find: (1) Using the x-ray ephemeris of Kitamoto et al. (ApJ, 384, 263 (1992), including the first and second derivatives of the period, the leading edge of the decline to minimum in the quiescent K light curve has not changed in phase since 1974. The duration of the minimum in the light curve has changed significantly between different epochs, becoming much broader in 1993 than it was previously. (2) In addition to an interstellar polarization component, it is likely Cyg X-3 has an intrinsic polarization component that is variable. The variations in the polarization do not show any diagnostic pattern with orbital phase. A crude analysis of the polarization suggests the intrinsic polarization of Cyg X-3 has a mean position angle of approximately 12 deg, nearly the same as the direction of the expanding radio lobes. This is consistent with circumstellar electrons scattering in an equatorial disk that is perpendicular to the lobe axis. (3) The mean position angle for the interstellar polarization in the direction of Cyg X-3 is 150 deg. This is nearly perpendicular to the axis of interstellar radio scattering seen in the extended (Very Long Baseline Inteferometry (VLBI) images. Since the position angle of interstellar polarization is the same as the projected magnetic field direction, this suggests the interstellar (not circumstellar) scattering must be taking place perpendicular to the interstellar magnetic field lines. (4) Cyg X-3 was observed at K during a flare on 1992 September 30 with a temporal resolution of 6 s. The flaring had rise and fall times of approximately 50 s with peak intensities up to 80 mJy. The flux between individual flare events never dropped to quiescent levels for the duration of our observations (approximately 2000 s).