Archaeoastronomy / Engineering

Paint Rock is a pictograph site in the state of Texas, USA. The assemblage contains over 1500 pictographs. Between 1996 and 2002 there were six active solar markers discovered. These six solar markers make Paint Rock the most active archaeoastronomical site in the region. It was hypothesized that more solar markers existed. We report on the discovery of two new solar markers. One records the winter solstice and the second records the spring and summer cross-quarter days.

Background/Objectives: In 1996, solar markers were discovered at Paint Rock, a pictograph site in the state of Texas, USA. The astronomy of the site had not been studied to answer how the cultures were able to place the pictographs so accurately, interacting with sunlight and shadow, recording vital astronomical knowledge. The primary focus of this paper is to provide details of the methodology used in discovering the horizon astronomy at the Paint Rock site. Methods/ Statistical Analysis: Three primary methods were employed, the field walking survey, photographic documentation, and surveying methods for archaeoastronomy. The field walking survey was the primary method to assess the site and conduct the search for the place of observation. Significant points were documented by photographs at all stages of the study. Then, using archaeoastronomy surveying techniques, a profile of the east and west horizon was performed, providing detailed celestial declinations along the horizon.Findings: A significant horizon "notch" from the place of observation was discovered through these methods on both the east and west horizon. The place of observation was tied to the material cultural record. Tying the horizon astronomy to the archaeology provides strong support in answering the question of how the native cultures were able to place the glyphs so accurately to interact with sunlight and shadow. Photographic evidence documents the findings. Applications/Improvement: The outcome of the findings has lead to the realization that these methods need to be applied to many unstudied sites worldwide. Establishing the horizon astronomy at a rock art site with solar markers adds significant support to any astronomical interpretation.

Massive stars are born predominantly as members of binary (or higher multiplicity) systems, and the presence of a companion can significantly alter their life and final fate. Therefore, any observed sample of massive stars or associated transients is likely to be significantly influenced by the effects of binarity. Here, we focus on the relationship between massive binary evolution and core-collapse supernova events. In the vast majority of the cases, the first core-collapse event happening in a binary system unbinds the two stars. Studying the population of companion stars, either at the supernova site, or as "widowed" stars long after the explosion, can be used to constrain the previous orbital evolution of the binary progenitor, and explosion physics of their former companion. Specifically, the population of "widowed" stars might provide statistical constraints on the typical amplitude of black hole natal kicks without seeing neither the black holes nor the transient possibly associated to their formation. Binarity also has a large impact on the predicted population of supernova sub-types, including hydrogen-rich type II supernovae, with a significant fraction of hydrogen-rich stars at explosions being either merger products or accretors.

The Paint Rock pictograph site on the Campbell Ranch near Paint Rock, Texas, contains over 1500 pictographs. A monument erected on the bluff by the State of Texas indicates it is the largest pictograph site in Texas. Twelve active solar markers have been identified at the site, and with additional observations, possibly more will be discovered. These solar interactions at the Paint Rock site make it one of the most interesting archaeoastronomical sites in Texas. An initial study of Paint Rock suggested that the native cultures did not use the horizon for calendrical purposes, as both the eastern and western horizon are flat and almost featureless. As a result, these characteristics led to our primary research question: How did the cultures so accurately place these rock art glyphs so that they could interact with light and shadow on important solar points of the year? We will detail our search for the place of observation, and the discovery of a significant horizon notch. Our observations support the discovery of the potential horizon calendar and show how it was tied to the material culture. These data answer the primary research question. Interpretation of rock art is one of the great challenges of cognitive archaeology. The existence of solar markers in rock art can provide the most rigorous interpretation and evidence of intentionality in rock art. We detail the accuracy and precision of two of the most significant solar markers. Finally, we propose a tool to evaluate rock art solar markers called the ‗Solar Marker Matrix of Intentionality'. This Matrix can be used to help identify potential solar markers and evaluate the strength of identified solar markers. Use of this tool will lead to a database for future statistical analysis.

Background/Objectives: In 1996, solar markers were discovered at Paint Rock, a pictograph site in the state of Texas, USA. The astronomy of the site had not been studied to answer how the cultures were able to place the pictographs so accurately, interacting with sunlight and shadow, recording vital astronomical knowledge. The primary focus of this paper is to provide details of the methodology used in discovering the horizon astronomy at the Paint Rock site. Methods/ Statistical Analysis: Three primary methods were employed, the field walking survey, photographic documentation, and surveying methods for archaeoastronomy. The field walking survey was the primary method to assess the site and conduct the search for the place of observation. Significant points were documented by photographs at all stages of the study. Then, using archaeoastronomy surveying techniques, a profile of the east and west horizon was performed, providing detailed celestial declinations along the horizon.Findings: A significant horizon "notch" from the place of observation was discovered through these methods on both the east and west horizon. The place of observation was tied to the material cultural record. Tying the horizon astronomy to the archaeology provides strong support in answering the question of how the native cultures were able to place the glyphs so accurately to interact with sunlight and shadow. Photographic evidence documents the findings. Applications/Improvement: The outcome of the findings has lead to the realization that these methods need to be applied to many unstudied sites worldwide. Establishing the horizon astronomy at a rock art site with solar markers adds significant support to any astronomical interpretation.