The orbital parameters of warm Jupiters serve as a record of their formation history, providing constraints on formation scenarios for giant planets on close and intermediate orbits. Here, we report ...the discovery of TIC 237913194b, detected in full frame images from Sectors 1 and 2 of TESS, ground-based photometry (CHAT, LCOGT), and FEROS radial velocity time series. We constrain its mass to \(M_\mathrm{P} = 1.942_{-0.091}^{+0.091}\,{\rm M_{J}} \), and its radius to \(R_\mathrm{P} = 1.117_{-0.047}^{+0.054}\,{\rm R_J}\), implying a bulk density similar to Neptune's. It orbits a G-type star (\({\rm M}_{\star} = 1.026_{-0.055}^{+0.057}\,{\rm M}_{\odot}\), \(V = 12.1\) mag) with a period of \(15.17\,\)d on one of the most eccentric orbits of all known warm giants (\(e \approx 0.58\)). This extreme dynamical state points to a past interaction with an additional, undetected massive companion. A tidal evolution analysis showed a large tidal dissipation timescale, suggesting that the planet is not a progenitor for a hot Jupiter caught during its high-eccentricity migration. TIC 237913194b further represents an attractive opportunity to study the energy deposition and redistribution in the atmosphere of a warm Jupiter with high eccentricity.
Astrophys.J.651:1256-1271,2006 We present infrared images and spectra of comets 2P/Encke,
67P/Churyumov-Gerasimenko, and C/2001 HT50 (LINEAR-NEAT) as part of a larger
program to observe comets inside ...of 5 AU from the sun with the Spitzer Space
Telescope. The nucleus of comet 2P/Encke was observed at two vastly different
phase angles (20 degrees and 63 degrees). Model fits to the spectral energy
distributions of the nucleus suggest comet Encke's infrared beaming parameter
derived from the near-Earth asteroid thermal model may have a phase angle
dependence. The observed emission from comet Encke's dust coma is best-modeled
using predominately amorphous carbon grains with a grain size distribution that
peaks near 0.4 microns, and the silicate contribution by mass to the sub-micron
dust coma is constrained to 31%. Comet 67P/Churyumov-Gerasimenko was observed
with distinct coma emission in excess of a model nucleus at a heliocentric
distance of 5.0 AU. The coma detection suggests that sublimation processes are
still active or grains from recent activity remain near the nucleus. Comet
C/2001 HT50 (LINEAR-NEAT) showed evidence for crystalline silicates in the
spectrum obtained at 3.2 AU and we derive a silicate-to-carbon dust ratio of
0.6. The ratio is an order of magnitude lower than that derived for comets
9P/Tempel 1 during the Deep Impact encounter and C/1995 O1 (Hale-Bopp).
Gaseous jets in Comet Hale-Bopp (1995 O1) Lederer, Susan M; Campins, Humberto; Osip, David J ...
Earth, moon, and planets,
01/1999, Letnik:
78, Številka:
1-3
Journal Article
We report the identification of gas jets in Comet Hale-Bopp in OH, NH, CN, C2, and C3. We also confirm the existence of CN jets as reported by Larson et al. (1997) and Mueller et al. (1998). Jet ...features can be seen in the March and April 1997 data sets, approximately a month before and after perihelion. Our results contribute to the understanding of both the chemical properties of the comet and the physical mechanisms necessary to produce these features. (Author)
Astrophys.J.611:200-207,2004 We present Keck/NIRSPEC near-IR images and Magellan/IMACS optical
spectroscopy of the host galaxy of GRB 031203. The host is an actively
star-forming galaxy at z=0.1055 ...+/- 0.0001. This is the lowest redshift GRB
to-date, aside from GRB 980425. From the hydrogen Balmer lines, we infer an
extinction of A_V = 3.62 +/- 0.25 or a total reddening E_T(B-V) = 1.17 +/- 0.1
toward the sightline to the nebular regions. After correcting for reddening, we
perform an emission-line analysis and derive an ISM temperature of
T=13400+/-2000K and electron density of n_e = 300 cm^(-3). These imply a
metallicity O/H=-0.72+/-0.15 dex and a roughly solar abundance pattern for N,
Ne, S, and Ar. Integrating Ha, we infer a dust-corrected star formation rate
(SFR) of > 11 Msol/yr. These observations have the following implications: (1)
the galaxy has a low K'-band luminosity L ~ L^*/5, typical of GRB host
galaxies; (2) the low redshift indicates GRB 031203 had an isotropic-equivalent
gamma-ray energy release smaller than all previous confirmed GRB events. The
burst discovery raises the likelihood of identifying many additional low z, low
flux events with Swift; (3) the large SFR, low metallicity, and the inferred
hard radiation field is suggestive of massive star formation, supporting the
collapsar model; (4) several lines of evidence argue against the identification
of GRB 031203 as an X-ray flash event.
We have measured the separations and position angles of the two components of the binary transneptunian object 1997 CQ29 at eight epochs. From these data we are able to constrain the orbit and mass ...of this binary system. The best fitting orbit has an orbital period of P = 312+/-3 days. The orbital eccentricity is e = 0.45+/-0.03 and the semimajor axis is a = 8,010+/-80 km. The mass of the system is surprisingly low at 0.42+/-0.02 x 10^18 kg. To account for the observed brightness consistent with the low mass and a range of plausible densities, the geometric albedo must be very high; for an assumed density of 1000 kg m^-3 we find a red geometric albedo of p_R = 0.37, an order of magnitude higher than has been generally assumed for transneptunian objects. If objects with comparably high albedos are common in the Kuiper belt, estimates of the mass of the belt must be significantly reduced. The semimajor axis of 1997 CQ29's orbit is 2.8% of the Hill radius of the primary, a value strikingly similar to this same ratio in other transneptunian binaries, main-belt binaries, and regular satellite systems.
We present the discovery of TYC9191-519-1b (TOI-150b, TIC 271893367) and HD271181b (TOI-163b, TIC 179317684), two hot Jupiters initially detected using 30-minute cadence Transiting Exoplanet Survey ...Satellite TESS photometry from Sector 1 and thoroughly characterized through follow-up photometry (CHAT, Hazelwood, LCO/CTIO, El Sauce, TRAPPIST-S), high-resolution spectroscopy (FEROS, CORALIE) and speckle imaging (Gemini/DSSI), confirming the planetary nature of the two signals. A simultaneous joint fit of photometry and radial velocity using a new fitting package juliet reveals that TOI-150b is a \(1.254\pm0.016\ R_J\), massive (\(2.61^{+0.19}_{-0.12}\ M_J\)) hot Jupiter in a \(5.857\)-day orbit, while TOI-163b is an inflated (\(R_P\) = \(1.478^{+0.022}_{-0.029} R_J\), \(M_P\) = \(1.219\pm0.11 M_J\)) hot Jupiter on a \(P\) = \(4.231\)-day orbit; both planets orbit F-type stars. A particularly interesting result is that TOI-150b shows an eccentric orbit (\(e=0.262^{+0.045}_{-0.037}\)), which is quite uncommon among hot Jupiters. We estimate that this is consistent, however, with the circularization timescale which is slightly larger than the age of the system. These two hot Jupiters are both prime candidates for further characterization --- in particular, both are excellent candidates for determining spin-orbit alignments via the Rossiter-McLaughlin (RM) effect and for characterizing atmospheric thermal structures using secondary eclipse observations considering they are both located closely to the James Webb Space Telescope (JWST) Continuous Viewing Zone (CVZ).
We present infrared images and spectra of comets 2P/Encke, 67P/Churyumov-Gerasimenko, and C/2001 HT50 (LINEAR-NEAT) as part of a larger program to observe comets inside of 5 AU from the sun with the ...Spitzer Space Telescope. The nucleus of comet 2P/Encke was observed at two vastly different phase angles (20 degrees and 63 degrees). Model fits to the spectral energy distributions of the nucleus suggest comet Encke's infrared beaming parameter derived from the near-Earth asteroid thermal model may have a phase angle dependence. The observed emission from comet Encke's dust coma is best-modeled using predominately amorphous carbon grains with a grain size distribution that peaks near 0.4 microns, and the silicate contribution by mass to the sub-micron dust coma is constrained to 31%. Comet 67P/Churyumov-Gerasimenko was observed with distinct coma emission in excess of a model nucleus at a heliocentric distance of 5.0 AU. The coma detection suggests that sublimation processes are still active or grains from recent activity remain near the nucleus. Comet C/2001 HT50 (LINEAR-NEAT) showed evidence for crystalline silicates in the spectrum obtained at 3.2 AU and we derive a silicate-to-carbon dust ratio of 0.6. The ratio is an order of magnitude lower than that derived for comets 9P/Tempel 1 during the Deep Impact encounter and C/1995 O1 (Hale-Bopp).
We present Keck/NIRSPEC near-IR images and Magellan/IMACS optical spectroscopy of the host galaxy of GRB 031203. The host is an actively star-forming galaxy at z=0.1055 +/- 0.0001. This is the lowest ...redshift GRB to-date, aside from GRB 980425. From the hydrogen Balmer lines, we infer an extinction of A_V = 3.62 +/- 0.25 or a total reddening E_T(B-V) = 1.17 +/- 0.1 toward the sightline to the nebular regions. After correcting for reddening, we perform an emission-line analysis and derive an ISM temperature of T=13400+/-2000K and electron density of n_e = 300 cm^(-3). These imply a metallicity O/H=-0.72+/-0.15 dex and a roughly solar abundance pattern for N, Ne, S, and Ar. Integrating Ha, we infer a dust-corrected star formation rate (SFR) of > 11 Msol/yr. These observations have the following implications: (1) the galaxy has a low K'-band luminosity L ~ L^*/5, typical of GRB host galaxies; (2) the low redshift indicates GRB 031203 had an isotropic-equivalent gamma-ray energy release smaller than all previous confirmed GRB events. The burst discovery raises the likelihood of identifying many additional low z, low flux events with Swift; (3) the large SFR, low metallicity, and the inferred hard radiation field is suggestive of massive star formation, supporting the collapsar model; (4) several lines of evidence argue against the identification of GRB 031203 as an X-ray flash event.
