Mission Critical Risk Taking: The Hubble Deep Field by Robert Williams

The document describes creating a 3D graph of the orbits of the 24 known trans-Neptunian objects (TNOs) that have been named. It extracts orbital parameter data for these 24 TNOs from the Minor Planet Center's website and uses a Python program and SPICE toolkit to plot their orbits in 3D. The resulting graph shows that the orbits have varying inclinations and many are nearly circular, while some elliptical orbits are obscured due to scale differences.

σT 4 where σ is the Stefan-Boltzmann constant. 1) The document discusses a computer simulation called Starsmasher that astrophysicists use to model binary star mergers like that of V1309 Scorpii. 2) Starsmasher uses smoothed particle hydrodynamics (SPH) which treats fluids as interacting parcels to efficiently simulate gas dynamics in stellar events. 3) The document provides details on how Starsmasher simulations work and the goals of modeling the light curve and visual appearance of V1309 Scorpii's merger event.

This document discusses three key questions in cosmology: dark matter, inflation, and dark energy. It provides evidence for dark matter from early observations of galaxy rotation curves and clusters. It also summarizes modern evidence from Planck for the matter content of the universe. Regarding inflation, it discusses the generic predictions and open questions about the inflaton field. For dark energy, it reviews evidence from supernovae and Planck and discusses theoretical challenges like the fine-tuning and coincidence problems. It also outlines proposed and ongoing experiments to better understand dark matter, inflation, and dark energy.

Asteroseismic constraints on K giants make it possible to infer radii, masses and ages of tens of thousands of field stars. Tests against independent estimates of these properties are however scarce, especially in the metal-poor regime. Here, we report the detection of solar-like oscillations in 8 stars belonging to the red-giant branch and red-horizontal branch of the globular cluster M4. The detections were made in photometric observations from the K2 Mission during its Campaign 2. Making use of independent constraints on the distance, we estimate masses of the 8 stars by utilising different combinations of seismic and non-seismic inputs. When introducing a correction to the Δν scaling relation as suggested by stellar models, for RGB stars we find excellent agreement with the expected masses from isochrone fitting, and with a distance modulus derived using independent methods. The offset with respect to independent masses is lower, or comparable with, the uncertainties on the average RGB mass (4 − 10%, depending on the combination of constraints used). Our results lend confidence to asteroseismic masses in the metal poor regime. We note that a larger sample will be needed to allow more stringent tests to be made of systematic uncertainties in all the observables (both seismic and non-seismic), and to explore the properties of RHB stars, and of different populations in the cluster.

This document discusses observations of six lensed starburst galaxies at redshift ~2.5 using the Atacama Large Millimeter/submillimeter Array (ALMA). The key findings are: 1) ALMA detected emission and absorption lines of the CH+ molecule in the spectra of five out of the six galaxies, indicating dense shocks and highly turbulent reservoirs of cool gas extending over 10 kiloparsecs outside the starburst regions. 2) The broad CH+ emission lines trace shocks moving at ~40 km/s within dense gas, while the absorption lines reveal turbulent reservoirs with velocities of ~400 km/s. 3) The turbulent reservoirs have radii of 10-20 kilopar

Studying the atmospheres of a statistically significant number of rocky, terrestrial exoplanets - including the search for habitable and potentially inhabited planets - is one of the major goals of exoplanetary science and possibly the most challenging question in 21st century astrophysics. However, despite being at the top of the agenda of all major space agencies and ground-based observatories, none of the currently planned projects or missions worldwide has the technical capabilities to achieve this goal. In this talk we present new results from the LIFE Mission initiative, which addresses this issue by investigating the scientific potential of a mid infrared nulling interferometer observatory. Here we will focus on the mission's yield estimates, our simulator software as well as various exemplary science cases such as observing Earth- and Venus-twins or searching for phosphine in exoplanetary atmospheres.

The APACHE Project is a long-term photometric survey aimed at discovering transiting exoplanets around hundreds of nearby M dwarf stars using an array of 400-mm telescopes. The project has conducted a pilot study and is now carrying out its long-term survey. It has already discovered several new variable stars and eclipsing binary systems. The survey works closely with other programs like GAPS and will benefit from precise Gaia parallax measurements of target stars.

- The authors detected an acceleration in the rotation rate of asteroid (25143) Itokawa through photometric observations spanning 2001 to 2013. - By measuring rotational phase offsets between observed and modeled lightcurves, they found a YORP acceleration of 3.54 ± 0.38 × 10−8 rad day−2, equivalent to a decrease in the asteroid's rotation period of about 45 ms per year. - Thermophysical modeling of the detailed shape model from the Hayabusa spacecraft could not reconcile the observed YORP strength unless the asteroid's center of mass is shifted by about 21 m along its long axis. This suggests Itokawa has two components with different densities that merged, either from a

This document describes an activity involving Hubble's law and the use of Cepheid variables as standard candles to measure distances to galaxies. It contains the following key points: 1) Cepheid variables have a direct relationship between their period and luminosity, allowing their distance to be estimated. Images show a Cepheid in galaxy M100 with an estimated period of [blank days]. 2) Galaxies' recessional velocities can be measured via redshift and are plotted against distance. A linear relationship is found, described by Hubble's law as v=Hd, where H is the Hubble constant. 3) Estimating H from the graph gives a value of [blank] km/s/Mpc, consistent with current estimates

This document describes observations of the pre-cataclysmic variable binary star system NN Serpentis using a CCD sensor. Light curve data of the system's apparent magnitude over time was collected, extracted from files, and calibrated. The light curve showed periodic fluctuations due to the orbit as well as a deep eclipse when the red dwarf passed in front of the white dwarf. By fitting a sine wave to the light curve, the orbital period was calculated to be 3.206 ± 0.023 hours. Additional parameters of the binary system were also determined from the observations and prior literature.

The document discusses the twin paradox of special relativity. It describes how one twin stays on Earth while the other travels to Alpha Centauri at 0.8 the speed of light and returns. When they reunite, the traveling twin is younger due to time dilation effects predicted by Einstein's theory of special relativity. The document uses vectors and an inner product defined on Minkowski spacetime to mathematically model the twins' trajectories and show that the traveling twin ages only 6 years while the Earth twin ages 10 years. It explains how special relativity introduces a new geometry where the shortest distance between points may not be a straight line.

The document summarizes research on the Kepler-9 planetary system. It finds that Kepler-9b and Kepler-9c are Saturn-sized planets with orbital periods of 19.24 and 39.08 days, respectively. Kepler-9d is a super-Earth with a period of 1.59 days. The Kepler-9 system was the first discovered using the transit method to have transit time variations (TTVs) detected for its planets. The research uses transit and radial velocity data to determine various properties of the three planets, including radius, orbital period, TTV, semi-major axis, mass, and density. It finds the first multi-planetary system where TTVs were detected, adding scientific value.

1) The Chandra X-ray Observatory was used to observe the supermassive black hole at the center of the Milky Way, Sgr A*, for a total of 3 megaseconds. 2) The observations revealed extended X-ray emission around Sgr A* that aligns spatially with a surrounding disk of massive stars. 3) Spectral analysis ruled out low-mass stars as the origin of the X-ray emission and instead found evidence that the emission is from a radiatively inefficient accretion flow onto the black hole, with an outflow present.

This document contains an 18-question multiple choice test on astronomy. The questions cover topics like the duration of seasons in the northern and southern hemispheres, the location of Polaris relative to the North Pole, how to calculate the magnifying power of a refracting telescope, factors that influence tidal amplitudes, the definition of right ascension and azimuth, conditions for a star to be circumpolar at a given latitude, factors that limit the light a telescope can collect, the definition of synodic period, factors that determine a star's color, conditions for a superior planet to appear to retrograde, conditions for an inferior planet to be at inferior conjunction, the best time of day to see an inferior planet at greatest eastern elongation, calculating

Progress in a group of investigations designed to discover some of the structural details in individual galaxies and in the Metagalaxy is reported in the following pages. (a) The first section is concerned with the distribution of cluster-type Cepheids in high galactic latitude. To the 169 already known in latitudes, greater than or equal to ± 20o , the systematic variable star programme carried on at Harvard has added 312, mostly fainter than magnitude 13-0. With allowance for absorption and for uncertainties yet remaining in the mean absolute magnitude of these stars, the thickness of the Milky Way, so far as this type of star is concerned, is not less than twenty-five kiloparsecs ; he extent of the Milky Way in its own plane, by the same criterion, is more than thirty kiloparsecs, perhaps much more. (b) The extent of the Milky Way in the anti-centre quadrant is considered on the basis of classical and cluster-type Cepheids ; provisionally it is found that the galactic system reaches to a distance of at least ten kiloparsecs in longitude 150o . (r) More than six hundred new variables have been found in the Large Magellanic Cloud and measured for position, ranges and median magnitudes ; the frequency of periods is not unlike that for the classical Cepheids in the galactic system ; the light curves also are comparable in all details. The Magellanic Cepheids, like the galactic classical Cepheids, are concentrated in regions of high star-density. (d) Further study of the period-luminosity relation in the Large Magellanic Cloud permits its revision and strengthening for the Cepheids of highest absolute magnitude. An observed deviation from the relation that had previously been found for the Small Cloud is probably to be attributed to scale error in the magnitude system. No seriously disturbing

Further analysis of the References- part 2. Some further analyses about directional recoil, cross sections, galaxy Physics and experiment-optimizations techniques. VIA Forum Astroparticle Physics Forum COSMOVIA Author: O.M. Lecian. Title: LHAASO Further references- part2. 28/03/2020 http://viavca.in2p3.fr/2010c_o_s_m_o_v_i_a__forum_sd24fsdf4zerfzef4ze5f4dsq34sdteerui45788789745rt7yr68t4y54865h45g4hfg56h45df4h86d48h48t7uertujirjtiorjhuiofgrdsqgxcvfghfg5h40yhuyir/viewtopic.php?f=73&t=3705&sid=c56cbf76f87536fc4c3ff216d9edaba2

This document reports the discovery of a newly discovered optical Einstein ring (ER) called the "Canarias Einstein Ring". It was discovered serendipitously in imaging data from the Dark Energy Camera. Follow-up spectroscopy with the Gran Telescopio CANARIAS confirmed the nature of the system, with the lens being an early-type galaxy at a redshift of z=0.581 and the source being a starburst galaxy at z=1.165. Analysis of the system determined the Einstein radius to be 2.16 arcseconds and the total enclosed mass producing the lensing effect to be 1.86 ± 0.23 × 1012 solar masses.

van Dokkum et al. (2023) reported the serendipitous discovery of a thin linear object interpreted as the trail of star-forming regions left behind by a runaway supermassive black hole (SMBH) kicked out from the center of a galaxy. Despite the undeniable interest in the idea, the actual physical interpretation is not devoid of diculty. The wake of a SMBH produces only small perturbations on the external medium, which has to be in exceptional physical conditions to collapse gravitationally and form a long (40 kpc) massive (3  109M) stellar trace in only 39 Myr. Here we oer a more conventional explanation: the stellar trail is a bulgeless galaxy viewed edge-on. This interpretation is supported by the fact that its position–velocity curve resembles a rotation curve which, together with its stellar mass, puts the object right on top of the Tully-Fisher relation characteristic of disk galaxies. Moreover, the rotation curve (Vmax 110 km s􀀀1), stellar mass, extension, width (z0 1.2 kpc), and surface brightness profile of the object are very much like those of IC 5249, a well-known local bulgeless edge-on galaxy. These observational

The dwarf irregular galaxy HIPASS J1131–31 was discovered as a source of HI emission at low redshift in such close proximity of a bright star that we call it Peekaboo. The galaxy resolves into stars in images with Hubble Space Telescope, leading to a distance estimate of 6.8 ± 0.7 Mpc. Spectral optical observations with the Southern African Large Telescope reveal HIPASS J1131–31 to be one of the most extremely metal-poor galaxies known with the gas-phase oxygen abundance 12+log(O/H) = 6.99±0.16 dex via the direct [OIII] 4363 line method and 6.87±0.07 dex from the two strong line empirical methods. The red giant branch of the system is tenuous compared with the prominence of the features of young populations in the color-magnitude diagram, inviting speculation that star formation in the galaxy only began in the last few Gyr

The document summarizes research finding a 17 billion solar mass black hole at the center of the galaxy NGC 1600. Key points: - Orbit modeling found the black hole mass to be 1.7x1010 solar masses, among the most massive found outside rich galaxy clusters. - NGC 1600 has an unusually diffuse, low surface brightness core, indicating a deficit of stars near the center compared to other galaxies. - A strong correlation was found between the black hole's sphere of influence radius and the galaxy's core radius for NGC 1600 and 20 other galaxies, supporting black hole binaries as the cause of core formation. - The black hole in NGC 1600 may be a descendant of the luminous quasars seen

This study aims to search for ultra-compact dwarf galaxies (UCDs) around local galaxies using photometric and spectroscopic data from surveys like SDSS and Hubble Space Telescope. The researchers discovered a new UCD, VO-UCD1, around the galaxy M59. Spectroscopy of VO-UCD1 found a velocity dispersion of 64 km/s and dynamical mass of 1.0 x 108 solar masses. Further study of newly discovered UCDs could provide insights into their origins, which remain unknown. The researchers plan to use HST to study UCD sizes and shapes and pursue additional data to understand black hole contributions to UCD masses.

This document summarizes a study that compiled a list of 220 spiral galaxies with quasars at their centers from the Sloan Digital Sky Survey Data Release 7. It analyzed the virial mass estimates of the quasars' supermassive black holes using three different calibration methods/datasets. Histograms of the black hole masses were created and showed a distribution ranging from 10^7 to 10^9 solar masses. Virial mass estimators relate the motion of gas around a black hole to its mass based on measured properties like emission line widths and luminosities.

Massive stars (those ≥8 solar masses at birth) have radiative envelopes that cannot sustain the dynamos that produce magnetic fields in lower mass stars. Despite this, ∼7% of massive stars have observed magnetic fields. We use multi-epoch interferometric and spectroscopic observations to characterise a magnetic binary system formed of two massive stars. We find that only one star of the binary is magnetic. Using the non-magnetic star as an independent reference clock to estimate the age of the system, we show that the magnetic star appears younger than its companion. The system properties, and a surrounding bipolar nebula, can be reproduced by a model in which this system was originally a triple within which two of the stars merged, producing the magnetic massive star. Thus, our results provide observational evidence that magnetic fields form in at least some massive stars through stellar mergers.

Mergers of neutron stars are known to be associated with short γ-ray bursts1–4 . If the neutron-star equation of state is sufficiently stiff (that is, the pressure increases sharply as the density increases), at least some such mergers will leave behind a supramassive or even a stable neutron star that spins rapidly with a strong magnetic field5–8 (that is, a magnetar). Such a magnetar signature may have been observed in the form of the X-ray plateau that follows up to half of observed short γ-ray bursts9,10. However, it has been expected that some X-ray transients powered by binary neutron-star mergers may not be associated with a short γ-ray burst11,12. A fast X-ray transient (CDF-S XT1) was recently found to be associated with a faint host galaxy, the redshift of which is unknown13. Its X-ray and host-galaxy properties allow several possible explanations including a short γ-ray burst seen off-axis, a low-luminosity γ-ray burst at high redshift, or a tidal disruption event involving an intermediatemass black hole and a white dwarf13. Here we report a second X-ray transient, CDF-S XT2, that is associated with a galaxy at redshift z = 0.738 (ref. 14). The measured light curve is fully consistent with the X-ray transient being powered by a millisecond magnetar. More intriguingly, CDF-S XT2 lies in the outskirts of its star-forming host galaxy with a moderate offset from the galaxy centre, as short γ-ray bursts often do15,16. The estimated event-rate density of similar X-ray transients, when corrected to the local value, is consistent with the event-rate density of binary neutron-star mergers that is robustly inferred from the detection of the gravitational-wave event GW170817.