Star Map Research Articles

Illuminating Mithraic Iconography: Mithras, God of Light, as the Milky Way

Although the iconography of the ancient Roman cult of Mithras is not thoroughly understood, it has been suggested by a number of scholars that the image of the deity sacrificing a bull (the tauroctony) referenced two constellations, namely Taurus and Scorpius. Roger Beck, Stanley Insler and others theorise that the animals of the tauroctony scene symbolise a trail of constellations between Taurus (the bull) and Scorpius (the scorpion). Building on the notion that the tauroctony may represent a simplified star map, this article details how Mithras’ body is analogous to the path of the Milky Way that bridges Taurus and Scorpius. This bifurcated section of the Milky Way mirrors the silhouette, scale and centrality of Mithras within the ancient reliefs. The concept of Mithras as the god of light and lord of genesis also resonates with the luminosity of the Milky Way, and with the location of the traditional soul gates at Taurus-Gemini and Scorpius Sagittarius, gates which were believed to represent the celestial portals for the soul at birth and death, respectively.

Higher Education Social Sustainability Case Study: Outcomes That Emerged During the Pandemic from The Outlook of the Autotelic Personality Questionnaire

The study reports on technology and business fields undergraduate adolescent (n=76) Autotelic Personalities using Questionnaire (APQ). The survey refers to a zodiac star chart for positioning AP qualities. High AP promotes engagement and satisfaction in periodic liveliness; thus, its potential is the quintessential set for traversed features that facilitate perceptual flow in daily life. This study utilized mixed-methods as mobile learning to analyze students' APQ perceptions using a Likert barometer, testing measurement validity (a, B) factorization. Perceptual levels on AP Meta-Skills: Curiosity, Persistence, Low Self-centeredness, Intrinsic Motivation, and Receptive-Active Model postulates the sum of Enjoyment and transformation of Challenge, neutrally perceived Enjoyment and transformation of Boredom, and Attentional Control. Each factor R-square considers discriminant validity issues because 4/7 of AP sum correlates more highly with variables outside the parent factor than with the parent factor. The study seeks resolution for biases and results in recommendations for changing pedagogical practice.

Image Degradation Model for Dynamic Star Maps in Multiple Scenarios

To meet the ground test requirements of star sensors, we establish the star map simulation algorithm and the interactive interface in multiple scenarios. The combination of the degradation model of star points, the imaging noise model, and the attitude disturbance model is introduced to solve the problem of different patterns of noise existing in the actual measurement, improving the traditional simulation model. In addition, a user-friendly interface design makes it easier for both scholars and average individuals to understand the parameters and then generate static single-frame star maps—or a series of dynamic sequence star maps—under various conditions. The results of the proposed star map simulation method are highly comparable to the actual captured star images, and this method can be applied for the tests and calibrations of star sensors.

A Star Pattern Recognition Algorithm Based on the Radial Companion-Circumferential Feature

Attitude measurement is an important core technology of vehicle flight. It is of great significance to ensure the vehicle’s accurate orbit entry and orbit change, high-performance flight, reliable ground communication, high-precision ground observation, and successful completion of various space missions. Star sensor is the core component to realize an autonomous attitude measurement of the vehicle. Autonomous star map recognition is a key technology in star sensor technology, and it is also the focus and difficulty of research. When the star sensor enters the initial attitude acquisition mode, according to the algorithm, the star sensor can quickly obtain the initial attitude and enter the normal working mode. This paper proposes a star pattern recognition algorithm based on the radial companion-circumferential feature with a noise compensation code to address the low recognition rate caused by position noise in the process of constructing star patterns in the traditional star pattern recognition algorithm based on the radial feature. In order to solve the problem of slow matching search speed, a maximum matching number algorithm has been innovatively adopted, which can improve the search efficiency in the process of star pattern recognition. Thus, the capacity of the star pattern recognition feature library is effectively reduced, and the stability and recognition rate of the improved star pattern recognition algorithm are further improved. The improved star pattern recognition algorithm first establishes radial and circumferential feature vectors based on the bit vector, then adds the noise compensation code according to the companion star position error, then modifies the radial and circumferential feature vectors, and finally calculates the minimum similarity difference between the feature vector of the star pattern observed by the star sensor and the feature vector of the navigation star in the feature library to obtain the unique star pattern recognition result. The identification star database adopts the maximum matching number algorithm, which can improve the search efficiency, reduce the amount of redundant matching, and shorten the matching time. The simulation results show that even in the presence of star position and magnitude noise, the improved star pattern recognition algorithm with radial companion-circumferential feature maintains a high recognition rate of more than 97 percent, demonstrating that the algorithm’s robustness is superior to other algorithms. The revised method described in this work outperforms the classic triangle algorithm and the radial feature star pattern recognition algorithm without compensation code in terms of algorithm robustness, recognition success rate, and recognition time.

Transmission Mysteries: Art and Technophilia

Transmission Mysteries: Art and Technophilia

ISSM-ELM - a guide star selection for a small-FOV star sensor based on the improved SSM and extreme learning machine.

The construction of a guide star catalog is crucial for a star sensor to achieve accurate star map recognition and attitude determination. At present, the methods of a guide star catalog for a large field of view (FOV) star sensor have been relatively mature. However, for a small-FOV star sensor, there are still certain problems, such as a large storage capacity of a guide star catalog, uneven distribution of stars, and easy occurrence of voids. To address these problems, we propose a construction method of a small-FOV star sensor guide star catalog based on the combination of the improved spherical spiral method (ISSM) and extreme learning machine (ELM) named the ISSM-ELM. First, a spiral reference point is used as an optical axis pointing of the star sensor, and the guide stars are preliminarily screened based on the star-diagonal distance between the star and the reference point, and the star-density and magnitude characteristics of the guide star. Then the ELM is used to supplement the guide star empty sky area to construct an integrity guide star catalog. The experimental results demonstrate that the proposed method can reduce the storage capacity of the guide star catalog, and improve its uniformity, integrity, and average brightness.

Mapping the stars on the revolving sphere and reckoning time: star catalogues, astronomical popularization, and practical functions

Abstract Among the astronomical texts devoted (in various ways) to the description/explanation of the stars and their phenomena, the sources allow us to identify a somehow ‘specific textual current’ that consists in those texts which were variously used or conceived as tools to convey knowledge of the ‘star map’ to a non-specialist public, even if they are different from each other in terms of structure and ‘technical-scientific’ level (especially in relation to the presence or not of the specific coordinates of the stars). The success of these texts over the course of the tradition is one of the main signs that suggest the diffusion of this subject matter in non-specialist contexts. According to the sources, the practical-applied benefit of such knowledge, above all in terms of ‘time reckoning’, seems to be at least one of the – certainly multiple and varied – reasons for this diffusion, and perhaps not the least significant one.

Recreating Abraham's Star Charts

I pause on the path, drop my sticks,and bend to read them like runes.Tell the stars, They said. So I do daily—I chart their breathless turning asI gather berries in the bush—Each twig's finger marks celestial points—North is Reckoner's Compass. South,Theory's Backbone. West, God's Thumbs,and East, Mount Moriah—Yet, I see more:Beyond—within—the navigable wildernessabove, 18 quasars guard the edge of theuniverse, like many-petaled amaranths.I peer into time—my tongue bends to liquidfire, tells of trillions of suns flung from theseorange hives.Now I perceive the beehive of beingness,honeycomb of allspace, linking stars intocells full of honeyed light throughout alltime.1I remember again words the Lord clappedin my palm—Write the stars. Write thestars. Write the stars.

Rapid star identification algorithm for fish-eye camera based on PPP/INS assistance

AbstractThe fish-eye star sensor with a field of view (FOV) of 180° is an important piece of equipment for attitude determination, which improves the visibility of stars significantly. However, it also brings the star identification (star-ID) difficulties because of imprecise calibrations. Thus, a fish-eye star-ID algorithm supported by the integration of the precise point positioning/inertial navigation system (PPP/INS) is proposed. At first, a reference star map is generated in combination with the distortion model of the fish-eye camera based on the position and attitude information from the PPP/INS. Then the star points are extracted in a specific neighbourhood of the reference star points. Subsequently, the extracted star points are individually tested and identified according to angular distance error. Finally, the real-time precise attitude is determined based on the star-ID results. Experimental results show that, 270–310 stars can be identified in a fish-eye star map with an average time of 0.03 s if the initial attitude error is smaller than 1.5° and an attitude determination accuracy better than 10″ can be achieved by support from PPP/INS.

Effect of proton beam irradiation on the tracking efficiency of CMOS image sensors

A star tracker provides accurate space positioning and reference for satellites, intercontinental strategic missiles, and other spacecrafts. However, the main imaging unit of the star sensor – the image sensor – is affected by the space radiation environment and, in turn, affects the precision with which the star is located by the star tracker. In this study, the parameter degradation of a CMOS image sensor (CIS) after proton irradiation with different fluences was investigated. An outfield test platform for star map collection was built using the star sensor lens and image collection system. The influence of dark current, dark-current nonuniformity, and photo-response nonuniformity of the irradiated CIS on the star diagonal distance measurement error and star-point centroid position detection accuracy was studied. The results showed that with increasing proton fluences, the CIS noise increased, leading to an increase in the error in the measured diagonal distance of the star and a decrease in the star’s position detection accuracy. Among these parameters, the dark current plays the greatest role in influencing the measurement accuracy of the star tracker. Furthermore, when a tracker is exposed to space radiation with fluences that are same as those used in this experiment, it is beneficial to reduce the integration time. This reduction in the time will decrease the noise and improve the position measurement accuracy.

Kinematical Analysis of Substructure in the Southern Periphery of the Large Magellanic Cloud

Abstract We report the first 3D kinematical measurements of 88 stars in the direction of several recently discovered substructures in the southern periphery of the Large Magellanic Cloud (LMC) using a combination of Gaia proper motions and radial velocities from the APOGEE-2 survey. More specifically, we explore stars in assorted APOGEE-2 pointings in a region of the LMC periphery where various overdensities of stars have previously been identified in maps of stars from Gaia and DECam. By using a model of the LMC disk rotation, we find that a sizable fraction of the APOGEE-2 stars have extreme space velocities that are distinct from, and not a simple extension of, the LMC disk. Using N-body hydrodynamical simulations of the past dynamical evolution and interaction of the LMC and Small Magellanic Cloud (SMC), we explore whether the extreme-velocity stars may be accounted for as tidal debris created in the course of that interaction. We conclude that the combination of LMC and SMC debris produced from their interaction is a promising explanation, although we cannot rule out other possible origins, and that these new data should be used to constrain future simulations of the LMC–SMC interaction. We also conclude that many of the stars in the southern periphery of the LMC lie outside of the LMC plane by several kiloparsecs. Given that the metallicity of these stars suggests that they are likely of Magellanic origin, our results suggest that a wider exploration of the past interaction history of the Magellanic Clouds is needed.

Holes

Holes Gabriela Ramos (bio) I yearn for collapsethe kind witnessed by the extinct, fanfarelike ultraviolet crocus buds in Marchbursting from the cold expanse. Yet there's no change in the star maps of oldno wonder in pieces of pavement, crumbsof pan dulce sprinkled in the sewage which settles in puddles—the Romans didn't build these roads. No awe in this subtle disfiguration,even though the stars, the planets, and their lovers, should be consumedbecome strands of diamonds and pearls drawn in,down the gullet and crushed. I crave the freefallto leave behind neighboring nebulae bleak and bitter,grand Ursa grasping at emptiness in my stead,or rather, no longer bear that final call. There is terror from cloud sweatcreeping, contracting, devouring, no, nibbling—these potholes, these boils on my back which only itch at the horizonin those moments before oblivion, bereft beneath that infinite blanket. The streets are empty, ribbons riddled with despairand insignificant to what lies in the center of most galaxies.Yes, a human and cosmic emulsion would hold more reliefbut, at least, potholes can be repaired. [End Page 92] Gabriela Ramos Gabriela Ramos (they/she) is a first-generation Salvadoran-American from Los Angeles, now working as an eighth grade English teacher in Jackson, Mississippi. Being queer, a Gemini, and Latinx, it's safe to say their relationship with gender and sexual identity is in a constant state of flux. They continue to read, write, and breathe poetry in the pockets of time between teaching teenagers and endless meetings. They are currently writing a collection of poems and essays focusing on lemons, grief, and potholes. Copyright © 2022 Pleiades and Pleiades Press

Space Debris Automation Detection and Extraction Based on a Wide-field Surveillance System

Abstract Wide-field telescopes with long exposure times have stronger space target detection capabilities. However, complex background sky conditions will still cause a series of difficulties in detecting space debris, such as a large number of star points, a large amount of noise, and the discontinuity and nonlinearity of the target. We propose a space debris automatic extraction channel with a high detection rate and low computational cost to solve these difficulties. We apply an improved median filter for noise elimination and then the double-structure morphological filter algorithm used to suppress the background of the star image to eliminate star points and noise. Then, the guided filter was used to eliminate residual noise, and star points were used to reduce the impact on the target. Finally, the improved Hough transform was also applied to detect the target in the image. Our automatic extraction algorithm is used in real astronomical star maps, including different orbiting satellites (star-tracking mode). These images were obtained by using a 280 mm diameter telescope, which was located in Changchun Observatory. The experimental results demonstrated the effectiveness of the extraction algorithm in this study. It can effectively detect and track space targets in a long-exposure wide-field surveillance system and has high positioning accuracy and low computational complexity, which solves the problem of space debris extraction under a complex background.

“Things” and Recovery From Trauma in Joukhader’s A Map of Salt and Stars

The present article explores the impact of “Things” on the healing journeys of the characters in Syrian American author Jennifer Zeynab Joukhader’s novel A Map of Salt and Stars (2018). It highlights the role of certain “Things” in Nour’s family’s healing process from the traumatic experiences of the Syrian war. The article also sheds light on the war’s reshaping of the objects and the individuals’ relationship with them. The objects that this article investigates are as varied as mundane utensils (a shattered plate), cherished souvenirs (Zahra’s bracelet), and even magical objects (Nour’s stone). Particularly, the article examines the establishment of the close association between the characters and these objects and the impact of this association on the family’s journey towards safety and recovery. For this reason, the present study is situated within the theoretical frameworks of the “Thing” theory and psychological trauma. This article argues that the close association that the characters establish with certain “Things” accompanies them during their grief and traumatic experiences, and subsequently initiates and facilitates their recovery.

Influence mechanism and recognition algorithm of CMOS active pixel sensor radiation damage on star sensor star map recognition

In order to analyze the causes of star sensor performance degradation and attitude measurement accuracy reduction in space radiation environment, the total ionizing dose effects on complementary metal oxide semiconductor (CMOS) star sensor performance are studied. By using an established outfield star sensor test system, the Orion Nebula and the zenith direction of the sky are imaged. Through the experimental processes of star map data acquisition, star point extraction and star map matching, the influence mechanisms of complementary metal oxide semiconductor active pixel sensor (CMOS APS) noises on background gray mean value of star map and number of identified stars are analyzed. A recognition algorithm for finding stars annihilated by radiated noise is proposed. Through theoretical derivation, the quantitative relationships between CMOS APS dark current noise, dark signal non-uniformity noise and photon response non-uniformity noise and star centroid positioning error are established. The γ radiation results show that the image gray-mean of the whole star map increases, the number of identified stars decreases, and the star point centroid positioning accuracy decreases, which seriously affect star map recognition of star sensor. This research provides a theoretical basis for the radiation-resistant reinforcement design of high precision star sensors.

A clinical review of enuresis and its associated psychiatric comorbidities

Enuresis is a common childhood condition treated by pediatricians and psychiatrists. Enuresis is also commonly referred as bedwetting. It is more prevalent among boys than girls. Enuresis is an involuntary voiding of urine continuing after an anticipated age of control in the absence of any organic abnormality. This review summarizes the current knowledge about epidemiology, diagnosis, etiological factors, psychiatric comorbidities, and behavioral (enuresis alarm and star charts) as well as pharmacological (desmopressin and imipramine) management of enuresis. It is important to understand the epidemiology, etiology, behavioral as well as pharmacological management, and screening for psychiatric comorbidities for the better outcome among the children with enuresis. Enuresis can be stressful physically as well as mentally for both child and parents. Many times, parents of children with enuresis either do not show willingness or hesitate to report the bedwetting behavior of their children due to perceived stigma related to enuresis. Hence, there is a paucity of data in this field that the detailed evaluation of the prevalence, causative factors, and risk factors is needed and of great value to understand the psychiatric comorbidities associated with enuresis for the better outcome. Psychological support and motivation are needed for both children and their parents for improving their treatment-seeking behavior and for an effective management of enuresis.

Rethinking the Nebra Sky Disk

The June 2020 issue of Physics Today features an image of the Nebra Sky Disk as the illustration for a book review by Bernie Taylor (page 53). The sky disk is one of the earliest depictions of recognizable astronomical objects and relationships. Researchers have analyzed the disk extensively and debated about when it was created and where it was found. The disk had been used for generations, and elements were added to it over the years.11. B. Ferreira, “A bitter archaeological feud over an ancient vision of the cosmos,” New York Times, 19 January 2021.The 30-centimeter disk originally featured elements that appear to be stars, the Sun or a full Moon, and a crescent Moon. Two golden arcs (one of which is now missing) were later added to the rim, which may have changed the disk’s function. It has been posited that those arcs represent the distances the sunrise and sunset travel between solstices at the latitude where the disk was purportedly found in 1999 near Nebra, Germany.Added later to the disk was another arc with two distinct lines along its length and many shorter ones radiating from its sides. Some have interpreted the object to be a mythical boat that ferries the Sun across the sky, with the short engraved strokes representing the oars.22. “The Nebra Sky Disc (Germany),” nomination form for the International Memory of the World Register (2012), https://en.unesco.org/sites/default/files/germany_nebra_sky_disc.pdf.The Nebra Sky DiskANAGORIA/WIKIMEDIA COMMONS/CC BY 3.0PPT|High resolutionImages of the disk are often oriented so that the third arc is on the bottom, emphasizing the possibility that the symbol represents a boat. But if the two side pieces indeed represent the extent of sunrises and sunsets throughout the year, then the disk is meant to be viewed as though the edge represents the horizon, as with modern overhead sky charts. If that is the case, the disk’s iconography might be interpreted differently.The disk could be depicting the star cluster nearly midway between the side arcs—often thought to be the Pleiades—in the sky to the south, as it would sometimes appear from the area around Nebra. The object often thought to be a Sun boat then would be a fuzzy swath, low in the sky and to the north. I propose that it was intended as a representation of the aurora borealis, which would have made periodic appearances in Nebra. That would agree with the observational nature of the rest of the disk.ReferencesSection:ChooseTop of pageReferences <<1. B. Ferreira, “A bitter archaeological feud over an ancient vision of the cosmos,” New York Times, 19 January 2021. Google Scholar2. “The Nebra Sky Disc (Germany),” nomination form for the International Memory of the World Register (2012), https://en.unesco.org/sites/default/files/germany_nebra_sky_disc.pdf. Google Scholar© 2021 American Institute of Physics.

Replacing the SpCas9 HNH domain by deaminases generates compact base editors with an alternative targeting scope

Base editors are RNA-guided deaminases that enable site-specific nucleotide transitions. The targeting scope of these Cas-deaminase fusion proteins critically depends on the availability of a protospacer adjacent motif (PAM) at the target locus and is limited to a window within the CRISPR-Cas R-loop, where single-stranded DNA (ssDNA) is accessible to the deaminase. Here, we reason that the Cas9-HNH nuclease domain sterically constrains ssDNA accessibility and demonstrate that omission of this domain expands the editing window. By exchanging the HNH nuclease domain with a monomeric or heterodimeric adenosine deaminase, we furthermore engineer adenine base editor variants (HNHx-ABEs) with PAM-proximally shifted editing windows. This work expands the targeting scope of base editors and provides base editor variants that are substantially smaller. It moreover informs of potential future directions in Cas9 protein engineering, where the HNH domain could be replaced by other enzymes that act on ssDNA.

High Update Rate Attitude Measurement Method of Star Sensors Based on Star Point Correction of Rolling Shutter Exposure.

Attitude update rate is one of the important indicators of star sensor performance. In order to resolve the problem of the low attitude update rate of star sensors, this paper proposes a star sensor attitude update method based on star point correction of rolling shutter exposure. Based on the characteristics of the asynchronous exposure of the rolling shutter, recursive estimation of the motion attitude and the corrected star point information were combined to realize multiple updates of the attitude in a single frame of the star map. Simulation and experimental results proved that the proposed method could increase the attitude update rate of a star sensor by 15 times, up to 150 Hz.

A new high-precision star map simulation model and experimental verification

In order to meet the ground test requirements of star sensors and solve the problem of the non-linearity between the apparent magnitude and the total grey value of the stars encountered in actual measurement, the colour index of stars and the theory of blackbody radiation are introduced to modify the simulation model which only used apparent magnitude formerly. In addition, simulation accuracy evaluation parameters are established based on the characteristics of star points. Finally, practical star observation experiments are carried out with a KAI-4021 detector as an example. Through the comparison between the measured and simulated star maps, the average grey-scale error is less than 12%, which is typically smaller than that of AGS model, and the error is reduced by 5% to 15%. The experimental results show that the proposed star map simulation method has higher accuracy and can provide star maps for star sensor ground tests. https://doi.org/10.1364/99.099999