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Our knowledge of the populations and occurrence rates of planets orbiting evolved intermediate-mass stars lags behind that for solar-type stars by at least a decade. Some radial velocity surveys have targeted these low-luminosity giant stars, providing some insights into the properties of their planetary systems. Here, we present the final data release of the Pan-Pacific Planet Search (PPPS), a 5 yr radial velocity survey using the 3.9 m Anglo-Australian Telescope. We present 1293 precise radial velocity measurements for 129 stars, and highlight 6 potential substellar-mass companions, which require additional observations to confirm. Correcting for the substantial incompleteness in the sample, we estimate the occurrence rate of giant planets orbiting low-luminosity giant stars to be approximately 7.8 |$^{+9.1}_{-3.3}$|  per cent. This result is consistent with the frequency of such planets found to orbit main-sequence A-type stars, from which the PPPS stars have evolved. [ABSTRACT FROM AUTHOR]

We present criteria for the selection of M-dwarfs down to G  < 14.5 using all-sky survey data, with a view to identifying potential M-dwarfs, to be confirmed spectroscopically by the FunnelWeb survey. Two sets of criteria were developed. The first, based on absolute magnitude in the Gaia G passband, with MG  > 7.7, selects 76,392 stars, with 81.0 per cent expected to be M-dwarfs at a completeness of >97 per cent. The second is based on colour and uses Gaia, WISE , and 2MASS all-sky photometry. This criteria identifies 94,479 candidate M-dwarfs, of which between 29.4 per cent and 47.3 per cent are expected to be true M-dwarfs, and which contains 99.6 per cent of expected M-dwarfs. Both criteria were developed using synthetic galaxy model predictions, and a previously spectroscopically classified set of M- and K-dwarfs, to evaluate both M-dwarf completeness and false-positive detections (i.e. the non-M-dwarf contamination rate). Both criteria used in combination demonstrate how each excludes different sources of contamination. We therefore developed a final set of criteria that combines absolute magnitude and colour selection to identify 74,091 stars. All these sets of criteria select numbers of objects feasible for confirmation via massively multiplexed spectroscopic surveys like FunnelWeb. [ABSTRACT FROM AUTHOR]

We report the discovery of four transiting hot Jupiters from the HATSouth survey: HATS-39b, HATS-40b, HATS-41b, and HATS-42b. These discoveries add to the growing number of transiting planets orbiting moderately bright (12.5 ≲ V ≲ 13.7) F dwarf stars on short (2-5 d) periods. The planets have similar radii, ranging from $1.33^{+0.29}_{-0.20}$  RJ for HATS-41b to $1.58^{+0.16}_{-0.12}$  RJ for HATS-40b. Their masses and bulk densities, however, span more than an order of magnitude. HATS-39b has a mass of 0.63 ± 0.13 MJ, and an inflated radius of 1.57 ± 0.12 RJ, making it a good target for future transmission spectroscopic studies. HATS-41b is a very massive 9.7 ± 1.6 MJ planet and one of only a few hot Jupiters found to date with a mass over 5 MJ. This planet orbits the highest metallicity star ([Fe/H] = 0.470 ± 0.010) known to host a transiting planet and is also likely on an eccentric orbit. The high mass, coupled with a relatively young age ( $1.34^{+0.31}_{-0.51}$  Gyr) for the host star, is a factor that may explain why this planet's orbit has not yet circularized. [ABSTRACT FROM AUTHOR]

Analysis of T dwarfs using model atmospheres has been hampered by the absence of reliable line lists for methane and ammonia. Newly computed high-temperature line lists for both of these important molecules are now available, so it is timely to investigate the appearance of the various absorption features in T dwarfs in order to better understand their atmospheres and validate the new line lists. We present high-quality R ~ 5000 Gemini/NIFS 1.0-2.4 μm spectra of the T8 standard 2MASS 0415-0935 and the T9 standard UGPS 0722-0540. We use these spectra to identify numerous methane and ammonia features not previously seen and we discuss the implications for our understanding of T dwarf atmospheres. Among our results, we find that ammonia is the dominant opacity source between ~ 1.233-1.266 μm in UGPS 0722-0540, and we tentatively identify several absorption features in this wavelength range in the T9's spectrum which may be due entirely to ammonia opacity. Our results also suggest that water rather than methane is the dominant opacity source in the red half of the J band of the T8 dwarf. Water appears to be the main absorber in this wavelength region in the T9 dwarf until ~1.31 μm, when methane starts to dominate. [ABSTRACT FROM AUTHOR]

We present the discovery of a very cold, very low mass, nearby brown dwarf using data from the NASA Wide-field Infrared Survey Explorer (WISE). The object, WISE J064723.23–623235.5, has a very red WISE color of W1–W2 > 3.77 mag and a very red Spitzer Space Telescope color of ch1–ch2 = 2.82 ± 0.09 mag. In JMKO –ch2 color (7.58 ± 0.27 mag) it is one of the two or three reddest brown dwarfs known. Our grism spectrum from the Hubble Space Telescope (HST) confirms it to be the seventeenth Y dwarf discovered, and its spectral type of Y1 ± 0.5 makes it one of the four latest-type Y dwarfs classified. Astrometric imaging from Spitzer and HST, combined with data from WISE, provides a preliminary parallax of π = 115 ± 12 mas (d = 8.7 ± 0.9 pc) and proper motion of μ = 387 ± 25 mas yr–1 based on 2.5 yr of monitoring. The spectrum implies a blue J–H color, for which model atmosphere calculations suggest a relatively low surface gravity. The best fit to these models indicates an effective temperature of 350-400 K and a mass of ∼5-30 MJup. Kinematic analysis hints that this object may belong to the Columba moving group, which would support an age of ∼30 Myr and thus an even lower mass of <2 MJup, but verification would require a radial velocity measurement not currently possible for a J = 22.7 mag brown dwarf. [ABSTRACT FROM AUTHOR]

We present i and z photometry for 25 T dwarfs and 1 L dwarf. Combined with published photometry, the data show that the i -- z, z -- Y, and z -- J colors of T dwarfs are very red, and continue to increase through to the late-type T dwarfs, with a hint of a saturation for the latest types with Teff ≈ 600 K. We present new 0.7-1.0 µm and 2.8-.2 µm spectra for the very late type T dwarf UGPS J072227.51-054031.2, as well as improved astrometry for this dwarf. Examination of the spectral energy distribution using new and published data, with Saumon & Marley models, shows that the dwarf has Teff = 505 ± 10 K, a mass of 3-11 MJupiter, and an age between 60 Myr and 1 Gyr. This young age is consistent with the thin disk kinematics of the dwarf. The mass range overlaps with that usually considered to be planetary, despite this being an unbound object discovered in the field near the Sun. This apparently young rapid rotator is also undergoing vigorous atmospheric mixing, as determined by the IRAC and WISE 4.5 µm photometry and the Saumon & Marley models. The optical spectrum for this 500 K object shows clearly detected lines of the neutral alkalis Cs and Rb, which are emitted from deep atmospheric layers with temperatures of 900-1200 K. [ABSTRACT FROM AUTHOR]

We report the discovery of 47 new T dwarfs in the Fourth Data Release (DR4) from the Large Area Survey (LAS) of the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey with spectral types ranging from T0 to T8.5. These bring the total sample of LAS T dwarfs to 80 as of DR4. In assigning spectral types to our objects we have identified eight new spectrally peculiar objects, and divide seven of them into two classes. H2O- H-early have a H2O- H index that differs with the H2O- J index by at least two subtypes. CH4- J-early have a CH4- J index that disagrees with the H2 index by at least two subtypes. We have ruled out binarity as a sole explanation for both types of peculiarity, and suggest that they may represent hitherto unrecognized tracers of composition and/or gravity. Clear trends in and are apparent for our sample, consistent with weakening absorption in the red wing of the K i line at 0.77 μm with decreasing effective temperature. We have used our sample to estimate space densities for T6–T9 dwarfs. By comparing our sample to Monte Carlo simulations of field T dwarfs for various mass functions of the form , we have placed weak constraints on the form of the field mass function. Our analysis suggests that the substellar mass function is declining at lower masses, with negative values of α preferred. This is at odds with results for young clusters that have been generally found to have . [ABSTRACT FROM AUTHOR]

Abstract We report differential I-band photometry of four early L dwarfs, obtained to study variability. We detect variability on a time-scale of hours in two objects, 2MASS 0746425+200032 (at a level of 0.007 mag = 6.5σ) and 2MASS 1108307+683017 (0.012 mag; 5σ). We also place upper limits of 0.02 mag (1σ) on the variability of two others. [ABSTRACT FROM AUTHOR]

We have used methane imaging techniques to identify the near-infrared counterpart of the bright Wide-field Infrared Survey Explorer (WISE) source WISE J163940.83–684738.6. The large proper motion of this source (≈3.″0 yr–1) has moved it, since its original WISE identification, very close to a much brighter background star—it currently lies within 1.″5 of the J = 14.90 ± 0.04 star 2MASS 16394085–6847446. Observations in good seeing conditions using methane-sensitive filters in the near-infrared J band with the FourStar instrument on the Magellan 6.5 m Baade telescope, however, have enabled us to detect a near-infrared counterpart. We have defined a photometric system for use with the FourStar J2 and J3 filters, and this photometry indicates strong methane absorption, which unequivocally identifies it as the source of the WISE flux. Using these imaging observations we were then able to steer this object down the slit of the Folded-port Infrared Echellette spectrograph on a night of 0.″6 seeing, and so obtain near-infrared spectroscopy confirming a Y0-Y0.5 spectral type. This is in line with the object's near-infrared-to-WISEJ3 – W2 color. Preliminary astrometry using both WISE and FourStar data indicates a distance of 5.0 ± 0.5 pc and a substantial tangential velocity of 73 ± 8 km s–1. WISE J163940.83–684738.6 is the brightest confirmed Y dwarf in the WISEW2 passband and its distance measurement places it among the lowest luminosity sources detected to date. [ABSTRACT FROM AUTHOR]

The closet exoplanets to the Sun provide opportunities for detailed characterization of planets outside the Solar System. We report the discovery, using radial velocity measurements, of a compact multiplanet system of super-Earth exoplanets orbiting the nearby red dwarf star GJ 887. The two planets have orbital periods of 9.3 and 21.8 days. Assuming an Earth-like albedo, the equilibrium temperature of the 21.8-day planet is ~350 kelvin. The planets are interior to, but close to the inner edge of, the liquid-water habitable zone. We also detect an unconfirmed signal with a period of ~50 days, which could correspond to a third super-Earth in a more temperate orbit. Our observations show that GJ 887 has photometric variability below 500 parts per million, which is unusually quiet for a red dwarf. [ABSTRACT FROM AUTHOR]