The Kruger 60 Star System may be the Origin of Interstellar Comet C/2019 Q4 Borisova

Kruger 60 -- a plausible home system of the interstellar comet C/2019 Q4

Authors:

Dybczyński et al

Abstract:

An interstellar comet C/2019 Q4 was discovered on August 30 by an amateur astronomer Gennady Borisov at MARGOT observatory (Crimea). One of the obvious questions is where does this object come from. Taking an orbit obtained by Nakano and published by MPC in CBET 4670 we numerically integrated the motion of C/2019 Q4, the sun and 647 stars or stellar systems from our list of potential stellar perturbers of cometary motion. As a result we obtained that 1 Myr ago C/2019 Q4 passed double star Kruger 60 at a small distance of 1.74 pc having an extremely small relative velocity of 3.43 km/s. Almost the same results were obtained from our own orbital solutions.

WFIRST Passes its Preliminary Design Review

The telescope for a major NASA astrophysics mission has passed a key review that the agency says keeps it on track for launch in the mid-2020s despite uncertainty about its funding for 2020 and beyond.

NASA announced Aug. 28 that the telescope assembly for the Wide Field Infrared Survey Telescope (WFIRST) mission passed its preliminary design review (PDR), allowing the project to continue work to finalize its design.

WFIRST, scheduled for launch in the mid-2020s, is NASA’s next flagship astrophysics mission after the James Webb Space Telescope. The mission will use a 2.4-meter mirror provided to NASA by the National Reconnaissance Office. That mirror is currently being modified by L3 Harris Technologies for use on WFIRST.

The telescope will later be equipped with both a wide-field imager instrument and a coronagraph, which blocks light from stars to allow direct imaging of planets and dust disks orbiting them. Both will have their own preliminary design reviews, along with one for the entire mission.

link.

Planet Nine may be Especially Faint in the red and Infrared

Comprehensive wide-band magnitudes and albedos for the planets, with applications to exo-planets and Planet Nine

Authors:

Mallama et al

Abstract:

Complete sets of reference magnitudes in all 7 Johnson-Cousins bands (U, B, V, R, I, RC and IC) and the 5 principal Sloan bands (u’, g’, r’, i', and z’) are presented for the 8 planets. These data are accompanied by illumination phase functions and other formulas which characterize the instantaneous brightness of the planets. The main source of Johnson-Cousins magnitudes is a series of individualized photometric studies reported in recent years. Gaps in that dataset were filled with magnitudes synthesized in this study from published spectrophotometry. The planetary Sloan magnitudes, which are established here for the first time, are an average of newly recorded Sloan filter photometry, synthetic magnitudes and values transformed from the Johnson-Cousins system. Geometric albedos derived from these two sets of magnitudes are consistent within each photometric system and between the systems for all planets and in all bands. This consistency validates the albedos themselves as well as the magnitudes from which they were derived. In addition, a quantity termed the delta stellar magnitude is introduced to indicate the difference between the magnitude of a planet and that of its parent star. A table of these delta values for exo-planets possessing a range of physical characteristics is presented. The delta magnitudes are for phase angle 90° where a planet is near the greatest apparent separation from its star. This quantity may be useful in exo-planet detection and observation strategies when an estimate of the signal-to-noise ratio is needed. Likewise, the phase curves presented in this paper can be used for characterizing exo-planets. Finally, magnitudes for the proposed Planet Nine are estimated, and we note that P9 may be especially faint at red and near-IR wavelengths.

The Puzzling Detection of X-rays From Pluto by Chandra

The Puzzling Detection of X-rays From Pluto by Chandra

Authors:

Lisse et al

Abstract:

Using Chandra ACIS-S, we have obtained imaging Xray spectrophotometry of the Pluto system in support of the New Horizons flyby on 14 July 2015. 174 ksec of observations were obtained on 4 visits in Feb 2014 to Aug 2015. We measured a net signal of 6.8 counts and a noise level of 1.2 counts in a comoving 11 x 11 pixel box (100 x 100 R_Pluto) in the 0.31 to 0.60 keV passband for a detection at > 99.95 C.L. The Pluto photons do not match the background spectrum, are coincident with a 90% flux aperture comoving with Pluto, and are not sky source confused. The mean 0.31 to 0.60 keV Xray power from Pluto is 200 MW, in the midrange of Xray power levels seen for known solar system emission sources: auroral precipitation, solar Xray scattering, and charge exchange (CXE) between solar wind (SW) ions & atmospheric neutrals. We eliminate auroral effects as a source, as Pluto has no known magnetic field & the New Horizons Alice UV spectrometer detected no airglow from Pluto during the flyby. Nano-scale atmospheric haze particles could lead to enhanced resonant scattering of solar X-rays from Pluto, but the energy signature of the detected photons does not match the solar spectrum and estimates of Plutos scattered Xray emission are > 100 times below the 3.9e-5 cps found in our observations. CXE emission from SW carbon, nitrogen, and oxygen ions can produce the energy signature seen, and the 6e25 neutral gas escape rate from Pluto deduced from New Horizons data can support the 3.0e24 Xray photons/sec emission rate required by our observations. Using the SW proton density and speed measured by the Solar Wind Around Pluto (SWAP) instrument in the vicinity of Pluto at the time of the photon emissions, we find too few SW minor ions flowing into the 11 x 11 pixel box centered on Pluto than are needed to support the observed emission rate unless the SW is significantly focused and enhanced in this region.

Lessons From Mayan Astronomy

Lessons from Mayan Astronomy

Author:

Loeb

Abstract:

The Mayan culture collected exquisite astronomical data for over a millennium. However, it failed to come up with the breakthrough ideas of modern astronomy because the data was analyzed within a mythological culture of astrology that rested upon false but mathematically sophisticated theories about the Universe. Have we learned the necessary lessons to prevent our current scientific culture from resembling Mayan Astronomy? Clearly, data collection by itself is not a guarantee for good science as commonly assumed by funding agencies. A vibrant scientific culture should cultivate multiple approaches to analyzing existing data and to collecting new data.

The Upper Limits For Oort Cloud Comets Based on X Ray Astronomy Observations

Upper limits to the number of Oort Cloud Objects based on serendipitous occultation events search in X-rays

Authors:

Chang et al

Abstract:

Using all the RXTE archival data of Sco X-1 and GX 5-1, which amount to about 1.6 mega seconds in total, we searched for possible occultation events caused by Oort Cloud Objects. The detection efficiency of our searching approach was studied with simulation. Our search is sensitive to object size of about 300 m in the inner Oort Cloud, taking 4000 AU as a representative distance, and of 900 m in the outer Oort Cloud, taking 36000 AU as the representative distance. No occultation events were found in the 1.6 Ms data. We derived upper limits to the number of Oort Cloud Objects, which are about three orders of magnitude higher than the highest theoretical estimates in the literature for the inner Oort Cloud, and about six orders higher for the outer Oort Cloud. Although these upper limits are not constraining enough, they are the first obtained observationally, without making any model assumptions about comet injection. They also provide guidance to such serendipitous occultation event search in the future.

Did two Supernovas 2.5 & 7.2 Milion Years ago Effect the World?

Research published in April provided "slam dunk" evidence of two prehistoric supernovae exploding about 300 light years from Earth. Now, a follow-up investigation based on computer modeling shows those supernovae likely exposed biology on our planet to a long-lasting gust of cosmic radiation, which also affected the atmosphere.

"I was surprised to see as much effect as there was," said Adrian Melott, professor of physics at the University of Kansas, who co-authored the new paper appearing The Astrophysical Journal Letters, a peer-reviewed express scientific journal that allows astrophysicists to rapidly publish short notices of significant original research.

"I was expecting there to be very little effect at all," he said. "The supernovae were pretty far way -- more than 300 light years -- that's really not very close."

According to Melott, initially the two stars that exploded 1.7 to 3.2 million and 6.5 to 8.7 million years ago each would have caused blue light in the night sky brilliant enough to disrupt animals' sleep patterns for a few weeks.

But their major effect would have come from radiation, which the KU astrophysicist said would have packed doses equivalent to one CT scan per year for every creature inhabiting land or shallower parts of the ocean.

link.

BBC on Planet Nine

Hat tip to Randy.

Observations of the 1006 Supernova by Ibn Sina (Avicenna)

An Arabic report about supernova SN 1006 by Ibn Sina (Avicenna)

Authors:

Neuhaeuser et al

Abstract:

We present here an Arabic report about supernova 1006 (SN 1006) written by the famous Arabic scholar Ibn Sina (Lat. Avicenna, AD 980-1037), which was not discussed in astronomical literature before. The short observational report about a new star is part of Ibn Sina's book called al-Shifa', a work about philosophy including physics, astronomy, and meteorology. We present the Arabic text and our English translation. After a detailed discussion of the dating of the observation, we show that the text specifies that the transient celestial object was stationary and/or tail-less ("a star among the stars"), that it "remained for close to three months getting fainter and fainter until it disappeared", that it "threw out sparks", i.e. it was scintillating and very bright, and that the color changed with time. The information content is consistent with the other Arabic and non-Arabic reports about SN 1006. Hence, it is quite clear that Ibn Sina refers to SN 1006 in his report, given as an example for transient celestial objects in a discussion of Aristotle's "Meteorology". Given the wording and the description, e.g. for the color evolution, this report is independent from other reports known so far.

China is Supposedly Launching Hubble Telescope Competitor Near Its Space Station in the Future

China is to launch an “optical module” along with the under-construction space station, said Zhang Yulin, Deputy to the National People’s Congress and Deputy Minister of Central Military Commission Equipment Development Department, on March 7, 2016. The “optical module” is similar to Hubble Space Telescope, but the field of view is 300 times that of Hubble.

The module would maintain a certain distance to orbit with the space station. When suffers malfunction or needs maintenance, it will dock to the space station and be operated by astronauts, Zhang said. This will solve the problem Hubble has encountered, when NASA had to send up astronauts particularly to repair it. This special design of China’s space station makes in-orbit maintenance possible, and can thus bring the numerous defunct satellites to life, Zhang said.

link.

Can mixed star-plus-wormhole systems mimic black holes?

Can mixed star-plus-wormhole systems mimic black holes?

Authors:

Dzhunushaliev et al

Abstract:

We consider mixed strongly gravitating configurations consisting of a wormhole threaded by two types of ordinary matter. For such systems, the possibility of obtaining static spherically symmetric solutions describing compact massive central objects enclosed by high-redshift surfaces (black-hole-like configurations) is studied. Using the standard thin accretion disk model, we exhibit potentially observable differences allowing to distinguish the mixed systems from ordinary black holes with the same masses.

Ancient Egyptians Observed Eclipsing Binary Algol ~3,000 Years ago

The Ancient Egyptian papyrus Cairo 86637 calendar is the oldest preserved historical document of naked eye observations of a variable star, the eclipsing binary Algol - a manifestation of Horus, a god and a king. This calendar contains lucky or unlucky prognoses for each day of one year. Lauri Jetsu and Sebastian Porceddu from the University of Helsinki have performed a statistical analysis of the Cairo Calendar mythological texts.

Their analysis revealed that the periods of Algol (2.85 days) and the Moon (29.6 days) strongly regulate the actions of deities in this calendar.

- Until now, there were only conjectures that many of the mythological texts of the Cairo Calendar describe astronomical phenomena. We can now unambiguously ascertain that throughout the whole year the actions of many deities in the Cairo Calendar are connected to the regular changes of Algol and the Moon, says Master of Science Sebastian Porceddu.

This research confirms that the first variable star, as well as its period, were discovered much earlier than was previously thought. These two "classical" milestones in the history of natural sciences need to be shifted three millennia backwards in time to 1244 - 1163 BC.

link.

Quark Star Found?

4U 1746–37: An ultra-low-mass compact star candidate

Author:

Li

Abstract:

The Rossi X-ray Timing Explorer observed three photospheric radius expansion bursts in 4U 1746-37, all with low touchdown fluxes. We discuss the possibiity of a low-mass neutron star in 4U 1746-37 if the touchdown flux corresponds to its Eddington limit. 4U 1746-37 is a dipping binary system which has a high inclination angle. Two geometric effects, the reflection of the far side accretion disc and the obscuration of the near side accretion disc have also been included. We apply a Monte-Carlo simulation, with typical values of hydrogen mass fraction and color correction factor, to constrain the mass and radius of the neutron star in 4U 1746-37. We found that the mass of 4U 1746-37 is 0.41+0.70–0.30 M® at 99.7 % confidence which is an ultra-low-mass compact star candidate. It could be reproduced by a self-bound compact star, i.e., quark star or quark-cluster star, from an ccretion-induced collapse process.

Studying a Korean Star Catalogue From 1396 AD

Study of the star catalogue (epoch AD 1396.0) recorded in ancient Korean astronomical almanac

Authors:

Jeon et al

Abstract:

The study of old star catalogues provides important astrometric data. Most of the researches based on the old star catalogues were manuscript published in Europe and from Arabic/Islam. However, the old star catalogues published in East Asia did not get attention. Therefore, among the East Asian star catalogues we focus on a particular catalogue recorded in a Korean almanac. Its catalogue contains 277 stars that are positioned in a region within 10° of the ecliptic plane. The stars in the catalogue were identified using the modern Hipparcos catalogue. We identified 274 among 277 stars, which is a rate of 98.9 per cent. The catalogue records the epoch of the stars’ positions as AD 1396.0. However, by using all of the identified stars we found that the initial epoch of the catalogue is AD 1363.1 ± 3.2. In conclusion, the star catalogue was compiled and edited from various older star catalogues. We assume a correlation with the Almagest by Ptolemaios. This study presents newly analysed results from the historically important astronomical data discovered in East Asia. Therefore, this star catalogue will become important data for comparison with the star catalogues published in Europe and from Arabic/Islam.

Sedna: One of the Exoplanets in our own Solar System?

Turns out, our seemly placid star had a criminal youth of cosmic proportions.

A recent study out from Leiden Observatory and Cornell University may shed light on the curious case of one of the solar system’s more exotic objects: 90377 Sedna.

A team led by astronomer Mike Brown discovered 90377 Sedna in late 2003. Provisionally named 2003 VB12, the object later received the name Sedna from the International Astronomical Union, after the Inuit goddess of the sea.

From the start, Sedna was an odd-ball. Its 11,400 year orbit takes it from a perihelion of 76 astronomical units (for context, Neptune is an average of 30 AUs from the Sun) to an amazing 936 AUs from the Sun. (A thousand AUs is 1.6% of a light year, and 0.4% of the way to Proxima Centauri, the closest star to our solar system). Currently at a distance of 86 AU and headed towards perihelion in 2076, we’re lucky we caught Sedna as it ‘neared’ (we use the term ‘near’ loosely in this case!) the Sun.

But this strange path makes you wonder what else is out there, and how Sedna wound up in such an eccentric orbit.

link.

I Hate Self Referencing, but! Worlds Made of Dark Matter Theorized

img src here.

However, the image is NOT mine, but rather a cool picture to add some visual for this.   There are no, theorized, worlds made of neutron- and white dwarf star stuff and...dark matter.  Take a look.

Somehow I Missed This: Tombaugh's Ashes are Aboard New Horizons

When the New Horizons spacecraft flew by Pluto it was the first time mankind has visited what is now called a dwarf planet.

On board that spacecraft, is a man – or rather his ashes – from New Mexico.

Clyde Tombaugh discovered Pluto as a young astronomer in Arizona. He later moved to New Mexico and founded the astronomy dept at New Mexico State University in 1955.

When NASA launched its Pluto mission 9 years ago, they placed a canister of Tombaugh’s ashes on board the spacecraft.

link.

hm.  Perhaps they ought to have named the spacecraft Tombaugh.  ah well.
 

NASA may Request Money in 2017 Budget to Begin Work to use ex NRO FIA Telescopes

NASA is considering requesting money in next year's budget to eventually start using two space telescopes it received from the United States' spy satellite agency, a senior official told Space.com.

NASA received the telescopes from the National Reconnaissance Office (NRO) in 2012. They have the same resolution as the agency's famous Hubble Space Telescope, but a field of view 200 times wider.

The telescopes are being eyed for use in a potential space mission called WFIRST-AFTA (the Wide Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets), which could launch as early as 2024 if it gets the final go-ahead. WFIRST-AFTA's science goals include learning more about the mysterious dark energy that is accelerating the expansion of the universe.

link.

Quasars, Blazars and a Ted Talk

We now Have the Technology to Detect Relavistic Starships

Limits and Signatures of Relativistic Spaceflight

Authors:

Yurtsever et al

Abstract:

While special relativity imposes an absolute speed limit at the speed of light, our Universe is not empty Minkowski spacetime. The constituents that fill the interstellar/intergalactic vacuum, including the cosmic microwave background photons, impose a lower speed limit on any object travelling at relativistic velocities. Scattering of cosmic microwave phtotons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances.

Step one. grab all the RAW kepler data.

Step two. write a search program like the supernova factory guys do.

Step Three.  Run, baby.  Run.  (or rather  debug, baby.  debug.  Then, run, baby.  Run!)

Step Four (probable).  Sigh with the lack of detections.

Step Five.  Grab everyone else's raw data too.  ;)

Rinse lather repeat.