Astronomy and Planetary Science Thread

[Rhinocrates]

To be taken with a grain of salt, since it's one of those futurological studies that go 'the future will be like the present, only more so'.

First human landing on an asteroid by 2073, say scientists

A team at NASA's Jet Propulsion laboratory have worked out a timeframe for crewed missions to the asteroid belt and beyond.

astronomy.com

[2205.08061] Impact of Economic Constraints on the Projected Timeframe for Human-Crewed Deep Space Exploration

Deep space exploration offers the most profound opportunity for the expansion of humanity and our understanding of the Universe, but remains extremely challenging. Progress will continue to be paced by uncrewed missions followed up by crewed missions to ever further destinations. Major space powers continue to invest in crewed deep space exploration as an important national strategy. An improved model based on previous work is developed, which projects the earliest possible launch dates for human-crewed missions from cis-lunar space to selected destinations in the Solar System and beyond based on NASA's historic budget trend and overall development trends of deep space exploration research. The purpose of the analysis is to provide a projected timeframe for crewed missions beyond Mars. Our findings suggest the first human missions from a spacefaring nation or international collaboration to the Asteroid Belt and Jovian System could be scheduled as soon as ~2071 to ~2087 and ~2101 to ~2121, respectively, while a launch to the Saturn System may occur by the year ~2132, with an uncertainty window of ~2129 to ~2153.

 

[FighterJock]

To be taken with a grain of salt, since it's one of those futurological studies that go 'the future will be like the present, only more so'.

First human landing on an asteroid by 2073, say scientists

A team at NASA's Jet Propulsion laboratory have worked out a timeframe for crewed missions to the asteroid belt and beyond.

astronomy.com

[2205.08061] Impact of Economic Constraints on the Projected Timeframe for Human-Crewed Deep Space Exploration

Deep space exploration offers the most profound opportunity for the expansion of humanity and our understanding of the Universe, but remains extremely challenging. Progress will continue to be paced by uncrewed missions followed up by crewed missions to ever further destinations. Major space powers continue to invest in crewed deep space exploration as an important national strategy. An improved model based on previous work is developed, which projects the earliest possible launch dates for human-crewed missions from cis-lunar space to selected destinations in the Solar System and beyond based on NASA's historic budget trend and overall development trends of deep space exploration research. The purpose of the analysis is to provide a projected timeframe for crewed missions beyond Mars. Our findings suggest the first human missions from a spacefaring nation or international collaboration to the Asteroid Belt and Jovian System could be scheduled as soon as ~2071 to ~2087 and ~2101 to ~2121, respectively, while a launch to the Saturn System may occur by the year ~2132, with an uncertainty window of ~2129 to ~2153.

It is not too impossible, by then we will have colonised Mars so the rockets can lift off from there instead of the Earth it will be so much easier to reach the Asteroid Belt.

 

[Flyaway]

Big fireball streaks across skies over at least 12 US states, Canada:

View: https://youtu.be/zO7uw--PAhc

 

[Flyaway]

Investigating the origin of optical and X-ray pulsations of the transitional millisecond pulsar PSR J1023+0038

PSR J1023+0038 is the first millisecond pulsar that was ever observed as an optical and UV pulsar. So far, it is the only optical transitional millisecond pulsar. The rotation- and accretion-powered emission mechanisms hardly individually explain the observed characteristics of optical pulsations. A synergistic model, combining these standard emission processes, was proposed to explain the origin of the X-ray/UV/optical pulsations. We study the phase lag between the pulses in the optical and X-ray bands to gain insight into the physical mechanisms that cause it. We performed a detailed timing analysis of simultaneous or quasi-simultaneous observations in the X-ray band, acquired with the XMM-Newton and NICER satellites, and in the optical band, with the fast photometers SiFAP2 (mounted at the 3.6 m Telescopio Nazionale Galileo) and Aqueye+ (mounted at the 1.8 m Copernicus Telescope). We estimated the time lag of the optical pulsation with respect to that in the X-rays by modeling the folded pulse profiles with two harmonic components. Optical pulses lag the X-ray pulses by ∼ 150 μs in observations acquired with instruments (NICER and Aqueye+) whose absolute timing uncertainty is much smaller than the measured lag. We also show that the phase lag between optical and X-ray pulsations lies in a limited range of values, δϕ∈ (0 − 0.15), which is maintained over timescales of about five years. This indicates that both pulsations originate from the same region, and it supports the hypothesis of a common emission mechanism. Our results are interpreted in the shock-driven mini pulsar nebula scenario. This scenario suggests that optical and X-ray pulses are produced by synchrotron emission from the shock that formed within a few light cylinder radii away (∼ 100 km) from the pulsar, where its striped wind encounters the accretion disk inflow.

[2211.12975] Investigating the origin of optical and X-ray pulsations of the transitional millisecond pulsar PSR J1023+0038

Study investigates pulsations of the millisecond pulsar PSR J1023+0038

European astronomers have conducted X-ray and optical observations of a transitional millisecond pulsar known as PSR J1023+0038. Results of the observational campaign, published November 23 on arXiv.org, yield important insights on the origins of pulsations of this source.

phys.org

 

[Rhinocrates]

Studies on an interstellar probe - though before you get too excited, it's to explore the interstellar medium (which is interesting anyway - it's what you have to go through to get to). Some good links, especially an ESA roadmap to 2050.

Interstellar Probe: Prospects for ESA Technologies | Centauri Dreams

A potential follow-up here. The boundary where the solar wind meets interstellar space is going to be a high priority research target if this comes to pass.

Plasma sail spacecraft could soar like an albatross to Alpha Centauri

A spacecraft equipped with a "sail" made from plasma could build up speed by repeatedly crossing the boundary at the edge of the solar system, just as an albatross soars by taking advantage of regions of different wind speeds

www.newscientist.com

Now, this is paywalled, but the keyword is 'albatross' ('What flavour is it?' 'It's albatross flavoured'), which leads to dynamic soaring and this study which you can read for free.

Dynamic soaring as a means to exceed the solar wind speed

A technique by which a spacecraft can interact with flows of ionized gas in space (the solar wind or interstellar medium) in order to be accelerated to velocities greater than the flow velocity is explored. Inspired by the dynamic soaring maneuvers performed by sea birds and gliders in which...

www.frontiersin.org

A conceptual mission is defined in which dynamic soaring is performed on the termination shock of the heliosphere, enabling a spacecraft to reach speeds approaching 2% of c within two and a half years of launch without the expenditure of propellant. The technique may comprise the first stage for a multistage mission to achieve true interstellar flight to other solar systems.

 

[Grey Havoc]

View: https://www.youtube.com/watch?v=PYR6EPlPDPU

 

[Grey Havoc]

Physicists Use Google's Quantum Computer to Create Holographic Wormhole Between Black Holes - Slashdot

"In an experiment that ticks most of the mystery boxes in modern physics, a group of researchers announced Wednesday that they had simulated a pair of black holes in a quantum computer," reports the New York Times [alternate URL here. But in addition, the researchers also sent a message...

science.slashdot.org

Hmmmmm....

 

[Flyaway]

Long-term multi-wavelength study of 1ES 0647+250

The BL Lac object 1ES 0647+250 is one of the few distant γ-ray emitting blazars detected at very high energies (VHE, ≳100 GeV) during a non-flaring state. It was detected with the MAGIC telescopes during its low activity in the years 2009-2011, as well as during three flaring activities in the years 2014, 2019 and 2020, with the highest VHE flux in the latter epoch. An extensive multi-instrument data set was collected within several coordinated observing campaigns throughout these years. We aim to characterise the long-term multi-band flux variability of 1ES 0647+250, as well as its broadband spectral energy distribution (SED) during four distinct activity states selected in four different epochs, in order to constrain the physical parameters of the blazar emission region under certain assumptions. We evaluate the variability and correlation of the emission in the different energy bands with the fractional variability and the Z-transformed Discrete Correlation Function, as well as its spectral evolution in X-rays and γ rays. Owing to the controversy in the redshift measurements of 1ES 0647+250 reported in the literature, we also estimate its distance in an indirect manner through the comparison of the GeV and TeV spectra from simultaneous observations with Fermi-LAT and MAGIC during the strongest flaring activity detected to date. Moreover, we interpret the SEDs from the four distinct activity states within the framework of one-component and two-component leptonic models, proposing specific scenarios that are able to reproduce the available multi-instrument data.

[2211.13268] Long-term multi-wavelength study of 1ES 0647+250

Research inspects a distant gamma-ray emitting blazar

An international team of astronomers has performed a long-term multiwavelength study of a distant gamma-ray emitting blazar known as 1ES 0647+250. Results of the research, published November 23 on arXiv.org, yield important insights into the long-term variability of this source.

phys.org

 

[Flyaway]

Decade Long Timing Study of the Black Widow Millisecond Pulsar J1544+4937

Results from 11 years of radio timing for eclipsing black widow millisecond pulsar (MSP) binary, J1544+4937, is presented in this paper. We report a phase-connected timing model for this MSP, using observations with the Giant Metrewave Radio Telescope (GMRT) at multiple frequencies and with Green Bank Telescope (GBT). This is the longest-duration timing study of any galactic field MSP with the GMRT. While extending the timing baseline from the existing 1.5 years to about a decade we report the first detection for a significant value of proper motion (μT∼ 10.14(5) mas/year) for this pulsar. Temporal variations of dispersion measure (ΔDM ∼10−3 pc cm−3) manifested by significant determination of 1st, 2nd, and 3rd order DM derivatives are observed along the line of sight to the pulsar. We also noticed frequency-dependent DM variations of the order of 10−3 pc cm−3, which could arise due to spatial electron density variations in the interstellar medium. This study has revealed a secular variation of the orbital period for this MSP for the first time. We investigated possible causes and propose that variation in the gravitational quadrupole moment of the companion could be responsible for the observed temporal changes in the orbital period.

[2211.14107] Decade Long Timing Study of the Black Widow Millisecond Pulsar J1544+4937

'Black widow' PSR J1544+4937 investigated in detail

Indian astronomers have performed long-term radio observations of a "black widow" millisecond pulsar known as PSR J1544+4937. Results of the observational campaign, published November 25 on the arXiv pre-print server, shed more light on the properties of this pulsar.

phys.org

 

[Flyaway]

New Measurement Resolves Key Astrophysical Fe XVII Oscillator Strength Problem

New Measurement Resolves Key Astrophysical Fe XVII Oscillator Strength Problem

Researchers have solved a long-standing puzzle surrounding iron emission lines, which are used to characterize laboratory and astrophysical plasmas.

journals.aps.org

”This strengthens the confidence in the quantum mechanical calculations used to analyze astrophysical spectra. This applies particularly to lines for which there are no experimental reference values," Kühn emphasizes the significance of the new result. Moreover, the spectra of the space telescopes can now be evaluated with greater accuracy.

This also applies to two large X-ray observatories that are soon to be launched into space: The Japanese-led X-Ray Imaging Spectroscopy Mission (XRISM, launch in May 2023) and the Athena X-Ray Observatory of the European Space Agency ESA (launch in the early 2030s).

X-ray analysis without doubt: Four-decade enigma of cosmic X-rays solved

An international team led by the Heidelberg MPl for Nuclear Physics has solved a decades-long problem in astrophysics with a high-precision experiment.

phys.org

 

[Flyaway]

After 30 years of planning and negotiations, construction begins this week on the Square Kilometre Array (SKA), the world’s largest radio-astronomy observatory. The giant instrument—to be built across sprawling sites in Australia and Africa—will collect the radio signals emitted by celestial objects and will hopefully shed light on some of the most enigmatic problems in astronomy, such as the nature of dark matter and how galaxies form.
On Monday, astronomers and local communities will travel to the remote sites in South Africa’s Northern Cape and Western Australia to celebrate the milestone with officials from the SKA Observatory (SKAO), the intergovernmental organization in charge of the telescopes.

Construction of World’s Largest Radio Observatory Is Finally Under Way

Two giant telescopes—one in Australia, the other in South Africa—will comprise the supersensitive Square Kilometer Array

www.scientificamerican.com

 

[Flyaway]

A nearby long gamma-ray burst from a merger of compact objects

Abstract
Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (greater than two seconds) duration are produced by the core-collapse of massive stars1, and those of short (less than two seconds) duration by the merger of compact objects, such as two neutron stars2. A third class of events with hybrid high-energy properties was identified3, but never conclusively linked to a stellar progenitor. The lack of bright supernovae rules out typical core-collapse explosions4,5,6, but their distance scales prevent sensitive searches for direct signatures of a progenitor system. Only tentative evidence for a kilonova has been presented7,8. Here we report observations of the exceptionally bright GRB 211211A, which classify it as a hybrid event and constrain its distance scale to only 346 megaparsecs. Our measurements indicate that its lower-energy (from ultraviolet to near-infrared) counterpart is powered by a luminous (approximately 1042 erg per second) kilonova possibly formed in the ejecta of a compact object merger.

A nearby long gamma-ray burst from a merger of compact objects - Nature

A bright, long-duration gamma-ray burst observed by the Swift observatory has hybrid high-energy properties, suggesting that its origin is the merger of a compact binary.

www.nature.com

Unusual gamma-ray burst reveals previously undetected hybrid neutron-star merger event

The standard view of gamma-ray bursts as a signature for different types of dying stars might need a rewrite. Recent astronomical observations, supported by theoretical modeling, reveal a new observational fingerprint of neutron-star mergers, which may shed light on the production of heavy...

phys.org

 

[Flyaway]

Deep X-ray and radio observations of the first outburst of the young magnetar Swift J1818.0-1607

Swift J1818.0-1607 is a radio-loud magnetar with a spin period of 1.36 s and a dipolar magnetic field strength of B~3E14 G, which is very young compared to the Galactic pulsar population. We report here on the long-term X-ray monitoring campaign of this young magnetar using XMM-Newton, NuSTAR, and Swift from the activation of its first outburst in March 2020 until October 2021, as well as INTEGRAL upper limits on its hard X-ray emission. The 1-10 keV magnetar spectrum is well modeled by an absorbed blackbody with a temperature of kT_BB~1.1 keV, and apparent reduction in the radius of the emitting region from ~0.6 to ~0.2 km. We also confirm the bright diffuse X-ray emission around the source extending between ~50'' and ~110''. A timing analysis revealed large torque variability, with an average spin-down rate nudot~-2.3E-11 Hz^2 that appears to decrease in magnitude over time. We also observed Swift J1818.0-1607 with the Karl G. Jansky Very Large Array (VLA) on 2021 March 22. We detected the radio counterpart to Swift J1818.0-1607 measuring a flux density of S_v = 4.38+/-0.05 mJy at 3 GHz, and a half ring-like structure of bright diffuse radio emission located at ~90'' to the west of the magnetar. We tentatively suggest that the diffuse X-ray emission is due to a dust scattering halo and that the radio structure may be associated with the supernova remnant of this young pulsar, based on its morphology.

[2211.12391] Deep X-ray and radio observations of the first outburst of the young magnetar Swift J1818.0-1607

Astronomers observe outburst of the young magnetar Swift J1818.0–1607

Using various space telescopes, European astronomers have performed deep X-ray and radio observations of a young magnetar known as Swift J1818.0–1607 during its outburst. Results of the observational campaign, published November 22 on arXiv.org, could help us better understand the nature of this...

phys.org

 

[Flyaway]

The Strange Mystery of the Asteroid That Wasn’t:

View: https://youtu.be/bzsWo5adxKo

 

[Flyaway]

The Rapidly Spinning Intermediate-Mass Black Hole 3XMM J150052.0+015452

A star tidally disrupted by a black hole can form an accretion disc with a super-Eddington mass accretion rate; the X-ray emission produced by the inner disc provides constraints on the black hole mass M∙ and dimensionless spin parameter a∙. Previous studies have suggested that the M∙ responsible for the tidal disruption event 3XMM J150052.0+015452 (hereafter J150052) is ∼105M⊙, in the intermediate black hole (IMBH) regime. Fitting multi-epoch XMM-Newton and Chandra X-ray spectra obtained after 2008 during the source's decade-long decay, with our latest slim accretion disc model gives M∙=2.0+1.0−0.3×105M⊙ (at 68% confidence) and a∙>0.97 (a 84.1% confidence lower limit). The spectra obtained between 2008-2014 are significantly harder than those after 2014, an evolution that can be well explained by including the effects of inverse-Comptonisation by a corona on the early-time spectra. The corona is present when the source accretion rate is super-Eddington, while there is no evidence for its effect in data obtained after 2014, when the mass accretion rate is around the Eddington-limit. Based on our spectral study, we infer that the corona is optically thick and warm (kTe=2.3+2.7−0.8 keV). Our mass and spin measurements of J150052 confirm it as an IMBH and point to a rapid, near extremal, spin. These M∙ and a∙ values rule out both vector bosons and axions of masses ∼10−16 eV.

[2211.16936] The Rapidly Spinning Intermediate-Mass Black Hole 3XMM J150052.0+015452

Tidal disruption event J150052 was caused by a rapidly spinning intermediate-mass black hole, study finds

Using NASA's Chandra and ESA's XMM-Newton space telescopes, astronomers from the Radboud University in the Netherlands and elsewhere have conducted X-ray observations of a tidal disruption event designated 3XMM J150052.0+015452, or J150052 for short. The results show that J150052 was triggered...

phys.org

 

[Grey Havoc]

Hubble Detects Ghostly Glow Surrounding Our Solar System - Slashdot

Astronomers searched through 200,000 archival images from Hubble Space Telescope and made tens of thousands of measurements on these images to look for any residual background glow in the sky. Like turning out the lights in a room, they subtracted the light from stars, galaxies, planets and the...

science.slashdot.org

 

[Rhinocrates]

Hubble Detects Ghostly Glow Surrounding Our Solar System - Slashdot

Astronomers searched through 200,000 archival images from Hubble Space Telescope and made tens of thousands of measurements on these images to look for any residual background glow in the sky. Like turning out the lights in a room, they subtracted the light from stars, galaxies, planets and the...

science.slashdot.org

Hmm, first observational evidence of the Oort cloud?

 

[FighterJock]

Hubble Detects Ghostly Glow Surrounding Our Solar System - Slashdot

Astronomers searched through 200,000 archival images from Hubble Space Telescope and made tens of thousands of measurements on these images to look for any residual background glow in the sky. Like turning out the lights in a room, they subtracted the light from stars, galaxies, planets and the...

science.slashdot.org

Hmm, first observational evidence of the Oort cloud?

It would not surprise me if it were the first evidence of the Oort Cloud Rinocrates, after Jan Oort‘s theory which he proposed back in the early part of the 20th Century.

 

[Grey Havoc]

So much for history - The Unwanted Blog (2)

The last few years have seen a lot of historic landmarks trashed. Get ready for another one: Holmdel Horn — Which Heard Evidence […]

unwantedblog.com

 

[Flyaway]

Hubble Detects Ghostly Glow Surrounding Our Solar System - Slashdot

Astronomers searched through 200,000 archival images from Hubble Space Telescope and made tens of thousands of measurements on these images to look for any residual background glow in the sky. Like turning out the lights in a room, they subtracted the light from stars, galaxies, planets and the...

science.slashdot.org

A new analysis of Hubble data has clinched it: There's too much light in the space around the Solar System.

Not much extra light, to be sure. Just a subtle, ghostly glow, a faint excess that can't be accounted for in a census of all the light-emitting objects.

The strongest possibility? A dust component to the Solar System that we haven't yet directly detected: tiny particles of dust and ice from a population of comets traveling inwards from the dark reaches of the Solar System, reflecting sunlight and generating a diffuse, global glow.

This source would be a bit closer to us than the extra light detected by the New Horizons space probe, which found an optical light excess in the space beyond Pluto, outside the Solar System.

A Ghostly Glow of Light Surrounds The Solar System, And Nobody Can Explain It

A new analysis of Hubble data has clinched it: There's too much light in the space around the Solar System.

www.sciencealert.com

 

[publiusr]

Now could that act as “ground clutter?”

Sometimes, if a tornado gets too near the radar, you can lose track of it.

I can’t help but wonder—-if you could get a big dish out past that noise—that will be the time SETI begins to hear un-attenuated whispers…double bubble design maybe silvered on the insides back to back.

The dish could be the sail….with a rod through the middle and feed horns at either end. Tighten on the forward end to bend to an Arecibo in the front. Once it hears something—you tighten the sail until it makes a dish in the back for contact with Earth.

 

[Flyaway]

Broadband mHz QPOs and spectral study of LMC X−4 with AstroSat

We report the results of broadband timing and spectral analysis of data from an AstroSat observation of the High Mass X-ray binary LMC X−4. The Large Area X-ray Proportional Counter (LAXPC) and Soft X-ray Telescope (SXT) instruments on-board the AstroSat observed the source in August 2016. A complete X-ray eclipse was detected with the LAXPC. The 3−40 keV power density spectrum showed the presence of coherent pulsations along with a ∼26 mHz quasi-periodic oscillation feature. The spectral properties of LMC X−4 were derived from a joint analysis of the SXT and LAXPC spectral data. The 0.5−25 keV persistent spectrum comprised of an absorbed high energy cutoff power law with photon index of Γ∼ 0.8 and cutoff at ∼16 keV, a soft thermal component with kTBB∼ 0.14 keV and Gaussian components corresponding to Fe Kα, Ne \textsc{ix} and Ne \textsc{x} emission lines. Assuming a source distance of 50 kpc, we determined 0.5--25 keV luminosity to be ∼2×1038 erg s−1.

[2212.01003] Broadband mHz QPOs and spectral study of LMC X$-$4 with AstroSat

Observations explore the properties of X-ray binary LMC X–4

Using the AstroSat spacecraft, Indian astronomers have investigated a high mass X-ray binary system known as LMC X–4. Results of the study, presented December 2 on arXiv.org, yield crucial insights into the properties of this source and shed more light on the quasi-periodic oscillations that it...

phys.org

 

[Flyaway]

The chemical compositions of multiple stellar populations in the globular cluster NGC 2808

Pseudo two-colour diagrams or Chromosome maps (ChM) indicate that NGC 2808 host five different stellar populations. The existing ChMs have been derived by the Hubble Space Telescope photometry, and comprise of stars in a small field of view around the cluster centre. To overcome these limitations, we built a ChM with U,B,I photometry from ground-based facilities that disentangle the multiple stellar populations of NGC 2808 over a wider field of view. We used spectra collected by GIRAFFE@VLT in a sample of 70 red giant branch (RGB) and seven asymptotic giant branch (AGB) stars to infer the abundances of C, N, O, Al, Fe, and Ni, which combined with literature data for other elements (Li, Na, Mg, Si, Ca, Sc, Ti, Cr and Mn), and together with both the classical and the new ground-based ChMs, provide the most complete chemical characterisation of the stellar populations in NGC 2808 available to date. As typical of the multiple population phenomenon in globular clusters, the light elements vary from one stellar population to another; whereas the iron peak elements show negligible variation between the different populations (at a level of ≲0.10~dex). Our AGB stars are also characterised by the chemical variations associated with the presence of multiple populations, confirming that this phase of stellar evolution is affected by the phenomenon as well. Intriguingly, we detected one extreme O-poor AGB star (consistent with a high He abundance), challenging stellar evolution models which suggest that highly He-enriched stars should avoid the AGB phase and evolve as AGB-manqué star.

[2212.01319] The chemical compositions of multiple stellar populations in the globular cluster NGC 2808

Astronomers investigate chemical composition of multiple stellar populations in NGC 2808

Using ESO's Very Large Telescope (VLT) and the Hubble Space Telescope (HST), astronomers have inspected the globular cluster NGC 2808. Results of the study, published December 2 on the arXiv pre-print repository, shed more light on the chemical composition of multiple stellar populations in this...

phys.org

 

[Flyaway]

Astronomers find that two exoplanets may be mostly water

Astronomers find that two exoplanets may be mostly water

A team led by UdeM astronomers has found evidence that two exoplanets orbiting a red dwarf star are "water worlds," planets where water makes up a large fraction of the volume. These worlds, located in a planetary system 218 light-years away in the constellation Lyra, are unlike any planets...

phys.org

Related video:

View: https://youtu.be/jjywIBBcP3I

 

[Rhinocrates]

Early days yet, so little detail and no conclusions but the news is that JWST is now turning its sight on TRAPPIST-1.

View: https://www.youtube.com/watch?v=WnGKBOgyXuk

 

[Flyaway]

The Possible Tidal Demise of Kepler's First Planetary System

Abstract
We present evidence of tidally-driven inspiral in the Kepler-1658 (KOI-4) system, which consists of a giant planet (1.1RJ, 5.9MJ) orbiting an evolved host star (2.9R⊙, 1.5M⊙). Using transit timing measurements from Kepler, Palomar/WIRC, and TESS, we show that the orbital period of Kepler-1658b appears to be decreasing at a rate $\dot{P}={131}_{-22}^{+20}$ ms yr−1, corresponding to an infall timescale $P/\dot{P}\approx 2.5\,\mathrm{Myr}$. We consider other explanations for the data including line-of-sight acceleration and orbital precession, but find them to be implausible. The observed period derivative implies a tidal quality factor ${Q}_{\star }^{{\prime} }={2.50}_{-0.62}^{+0.85}\times {10}^{4}$, in good agreement with theoretical predictions for inertial wave dissipation in subgiant stars. Additionally, while it probably cannot explain the entire inspiral rate, a small amount of planetary dissipation could naturally explain the deep optical eclipse observed for the planet via enhanced thermal emission. As the first evolved system with detected inspiral, Kepler-1658 is a new benchmark for understanding tidal physics at the end of the planetary life cycle.

ShieldSquare Captcha

iopscience.iop.org

Alien planet found spiraling to its doom around an aging star

For the first time, astronomers have spotted an exoplanet whose orbit is decaying around an evolved, or older, host star. The stricken world appears destined to spiral closer and closer to its maturing star until collision and ultimate obliteration.

phys.org

 

[Flyaway]

Exploring the single-pulse behaviours of PSR J0628+0909 with FAST

ABSTRACT
More than 100 rotating radio transients (RRATs) have been discovered since 2006. However, it is unclear whether RRATs radiate in nulling states. PSR J0628+0909 has been classified as an RRAT. In this paper, we study the single pulses and integrated pulse profile of PSR J0628+0909 to check whether we can detect pulsed radio emission in the nulling states. We also aim to study the polarization of the RRAT and its relationship to the general pulsar population. We used the Five-hundred-meter Aperture Spherical radio Telescope (FAST) to observe PSR J0628+0909 in the frequency range from 1.0 to 1.5 GHz. We searched for strong single pulses and looked for pulsed emission in the RRAT nulling states. Polarization profiles, the single-pulse energy distribution, and waiting-time statistics were measured. The Faraday rotation measure and dispersion measure values are updated with the current observation. The single-pulse polarization behaviours show great diversity, similar to the case of pulsars. Based on the integrated pulse profile and single-pulse energy statistics, we argue that continuous pulsar-like emission exists in addition to the transient-like burst emission for PSR J0628+0909. We find that the pulse waiting time is not correlated with the pulse energy and conclude that the strong transient emission of RRAT is not generated by the energy store–release mechanism.

Exploring the single-pulse behaviours of PSR J0628+0909 with FAST

ABSTRACT. More than 100 rotating radio transients (RRATs) have been discovered since 2006. However, it is unclear whether RRATs radiate in nulling states. PSR J

academic.oup.com

 

[jeffb]

https://twitter.com/x/status/1605450494859771904

View: https://twitter.com/astrophilesz/status/1605450494859771904?t=E5pCrZqg2B3BCQXG9DCl4g&s=19

J1407b: Super-Saturn - Exoplanet Exploration: Planets Beyond our Solar System

Artist’s conception of the extrasolar ring system circling the young giant planet or brown dwarf J1407b. The rings are shown eclipsing the young sun-like star J1407, as they would have appeared in early 2007.

exoplanets.nasa.gov

 

[Flyaway]

Two temperate Earth-mass planets orbiting the nearby star GJ 1002

Two temperate Earth-mass planets orbiting the nearby star GJ 1002 | Astronomy & Astrophysics (A&A)

Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics

www.aanda.org

The star system is comparatively close to us in cosmological terms at just under sixteen light years distant, and features two planets with masses similar to the Earth’s orbiting in the star’s habitable zone. There may also be a third larger planet further out in orbit about the host star.

Two Earth-mass exoplanets orbiting nearby star discovered

Using the radial velocity (RV) method, an international team of astronomers has discovered two new exoplanets transiting a nearby M-dwarf star known as GJ 1002. The newfound alien worlds have masses similar to that of our planet and orbit the host star in its habitable zone. The finding is...

phys.org

 

[Flyaway]

Timing analysis of the 2022 outburst of the accreting millisecond X-ray pulsar SAX J1808.4−3658: hints of an orbital shrinking

We present a pulse timing analysis of NICER observations of the accreting millisecond X-ray pulsar SAX J1808.4−3658 during the outburst that started on 2022 August 19. Similar to previous outbursts, after decaying from a peak luminosity of ≃1×1036ergs−1 in about a week, the pulsar entered in a ∼1 month-long reflaring stage. Comparison of the average pulsar spin frequency during the outburst with those previously measured confirmed the long-term spin derivative of ν˙SD=−(1.15±0.06)×10−15Hzs−1, compatible with the spin-down torque of a ≈1026Gcm3 rotating magnetic dipole. For the first time in the last twenty years, the orbital phase evolution shows evidence for a decrease of the orbital period. The long-term behaviour of the orbit is dominated by a ∼11s modulation of the orbital phase epoch consistent with a ∼21yr period. We discuss the observed evolution in terms of a coupling between the orbit and variations in the mass quadrupole of the companion star.

[2212.09778] Timing analysis of the 2022 outburst of the accreting millisecond X-ray pulsar SAX J1808.4$-$3658: hints of an orbital shrinking

Research investigates the latest outburst of pulsar SAX J1808.4−3658

Using the Neutron Star Interior Composition Explorer (NICER) onboard the International Space Station (ISS), an international team of astronomers has inspected the recent outburst of an accreting millisecond X-ray pulsar known as SAX J1808.4−3658. Results of the study, published December 19 on...

phys.org

 

[Flyaway]

Investigating stellar variability in the open cluster region NGC 381

We study variable stars in the field of the open cluster NGC 381 using photometric data observed over 27 nights and identify a total of 57 variable stars out of which five are member stars. The variable stars are classified based on their periods, amplitudes, light curve shapes, and locations in the H-R diagram. We found a rich variety of variable stars in the cluster. We identified a total of 10 eclipsing binaries out of which 2 are Algol type (EA) while 8 are W UMa type (EW) binaries. The estimated ages of these EW binaries are greater than 0.6 Gyr which is in agreement with the formation time constraint of > 0.6 Gyr on short-period eclipsing binaries. The estimation of the physical parameters of the three EW type binaries is done using PHOEBE model-fitting software. The pulsating variable stars include one each from {\delta} Scuti and {\gamma} Dor variability class. We determined the pulsation modes of pulsating variables with the help of the FAMIAS package. We obtained 15 rotational variables stars comprising four dwarf stars identified on the basis log(g) versus log(Tef f ) diagram. These dwarf stars are found to have generally larger periods than the remaining rotational variables.

[2212.09386] Investigating stellar variability in the open cluster region NGC 381

Indian astronomers detect dozens of variable stars in the NGC 381 region

Astronomers from the Aryabhatta Research Institute of observational sciencES (ARIES) and from the Physical Research Laboratory in India report the detection of 57 variable stars in the field of the open cluster NGC 381. The discovery was detailed in a paper published December 19 on the arXiv...

phys.org

 

[jeffb]

https://twitter.com/x/status/1608166691275509761

View: https://twitter.com/NASAExoplanets/status/1608166691275509761?t=fgK8KFfzucAfBGRPn8bqoA&s=19

Strange New Worlds - NASA Science

A world with two suns, a lava planet, and a world trapped in eternal darkness are just some of the exoplanets discovered so far.

exoplanets.nasa.gov

 

[FighterJock]

https://twitter.com/x/status/1608166691275509761

View: https://twitter.com/NASAExoplanets/status/1608166691275509761?t=fgK8KFfzucAfBGRPn8bqoA&s=19

Strange New Worlds - NASA Science

A world with two suns, a lava planet, and a world trapped in eternal darkness are just some of the exoplanets discovered so far.

exoplanets.nasa.gov

5,235 exoplanets discovered so far and the number will surely creep up over the next year, who would have thought that when we discovered the first exoplanet back in the early 1990s that we would have discovered more by this time.

 

[Grey Havoc]

Every Planet In the Solar System Will Be Visible Tonight - Slashdot

An anonymous reader quotes a report from Space.com: Take a grand tour of the solar system tonight (Dec. 28) as each of the planets in the solar system will be visible at the same time. As 2022 comes to an end, skywatchers can take in the rare sight of all of the planets in our solar system...

science.slashdot.org

 

[jeffb]

https://twitter.com/x/status/1608166691275509761

View: https://twitter.com/NASAExoplanets/status/1608166691275509761?t=fgK8KFfzucAfBGRPn8bqoA&s=19

Strange New Worlds - NASA Science

A world with two suns, a lava planet, and a world trapped in eternal darkness are just some of the exoplanets discovered so far.

exoplanets.nasa.gov

5,235 exoplanets discovered so far and the number will surely creep up over the next year, who would have thought that when we discovered the first exoplanet back in the early 1990s that we would have discovered more by this time.

It's incredible stuff really, unimaginable only a couple of decades ago. JWST planning on detailed analysis of exoplanet atmospheres any day now.

 

[Flyaway]

Vela pulsar wind nebula X-rays are polarized to near the synchrotron limit

Abstract
Pulsar wind nebulae are formed when outflows of relativistic electrons and positrons hit the surrounding supernova remnant or interstellar medium at a shock front. The Vela pulsar wind nebula is powered by a young pulsar (B0833-45, aged 11,000 years)1 and located inside an extended structure called Vela X, which is itself inside the supernova remnant2. Previous X-ray observations revealed two prominent arcs that are bisected by a jet and counter jet3,4. Radio maps have shown high linear polarization of 60% in the outer regions of the nebula5. Here we report an X-ray observation of the inner part of the nebula, where polarization can exceed 60% at the leading edge—approaching the theoretical limit of what can be produced by synchrotron emission. We infer that, in contrast with the case of the supernova remnant, the electrons in the pulsar wind nebula are accelerated with little or no turbulence in a highly uniform magnetic field.

Vela pulsar wind nebula X-rays are polarized to near the synchrotron limit - Nature

Polarization can exceed 60% at the leading edge of the inner part of the Vela pulsar wind nebula; in contrast with the case of the supernova remnant, the electrons in the pulsar wind nebula are accelerated with little or no turbulence in a highly uniform magnetic field.

www.nature.com

Imaging the magnetic field in the acceleration zone of the Vela pulsar

An international team of space scientists has imaged the magnetic field that exists in the acceleration zone of the Vela pulsar. In their paper published in the journal Nature, the group describes how they used data from NASA's Imaging X-Ray Polarimetry Explorer (IXPE) mission to obtain indirect...

phys.org

 

[Flyaway]

Variability and Spectral Behavior of Gamma-ray Flares of 3C 279

3C 279 showed enhanced flux variations in Fermi-LAT {\gamma}-ray observations from January to June 2018. We present a detailed Fermi-LAT analysis to investigate the variability and spectral behaviors of 3C 279 during the {\gamma}-ray flares in 2018. In this work, we analyzed the {\gamma}-ray spectra and found that the spectra in either the flaring or quiescent states do not show any clear breaks (or cutoffs). This indicates that the dissipation region is outside the broad-line region, and the energy dissipation may be due to the inverse Compton process of scattering the dust torus infrared photons, this result is also consistent with that in Tolamatti et al. An external inverse Compton scattering of dusty torus (DT) photons is employed to calculate the broadband spectral energy distribution (SED). This model was further supported by the fact that we found flare decay timescale was consistent with the cooling time of relativistic electrons through DT photons. During the SED modeling, a relatively harder spectrum for the electron energy distribution (EED) is found and suggests these electrons may not be accelerated by the shock that happened in the dissipation region. Besides, the magnetic reconnection is also ruled out due to a low magnetization ratio. Thus, we suggest an injection of higher-energy electrons from outside the blob and raising the flare.

[2212.13395] Variability and Spectral Behavior of Gamma-ray Flares of 3C 279

Researchers inspect gamma-ray flares of the blazar 3C 279

Using NASA's Fermi spacecraft, Chinese astronomers have investigated the variability and spectral behavior of gamma-ray flares in a distant blazar known as 3C 279. Results of the study, presented in a paper published in the Publications of the Astronomical Society of the Pacific, could help...

phys.org

 

[Flyaway]

Study investigates the evolution of X-ray binary system GX 301-2

Study investigates the evolution of X-ray binary system GX 301-2

Astronomers from Argentina and France have investigated the evolutionary history of an eccentric high-mass X-ray binary known as GX 301-2. Results of the study, published December 22 on the arXiv pre-print repository, deliver important insights into the origin of this object and could help...

phys.org

 

[Flyaway]

Newly discovered comet could be visible to the naked eye in Jan. 2023:

View: https://youtu.be/iaDlbYQ4GrU

 

[Rhinocrates]

Habitable Worlds Observatory announced. Maybe it will see first light in the early 2040s.

Science | AAAS

www.science.org

Early days yet, with details of its architecture yet to be worked out. About 12m diameter, stationed at L2, designed for robotic servicing, unlike Webb.

It's descended from the LUVOIR study from 2015-19, FYI:

Astronomers propose giant space telescope to replace Hubble - Nature

Segmented mirror four or five times wider than Hubble's would peer directly at exoplanets.

www.nature.com

LUVOIR: Large UV/Optical/Infrared Surveyor

The Large UV/Optical/IR Surveyor (LUVOIR) is a concept for a highly capable, multi-wavelength space observatory with ambitious science goals.

asd.gsfc.nasa.gov