Red Supergiants (RSGs) probe an advanced stage in the evolution of massive stars that is of particular interest in providing chemical and energy feedback into their surrounding environments. Using data from the Hubble Space Telescope (HST) and the Spitzer Space Telescope (Spitzer), we identify RSG stars in the nearby face-on spiral galaxy NGC6946. Our goal was to identify RSGs, constrian their ages, compare the ages and brightnesses  to the existing models, and finally infer an initial mass for the star. Understanding RSGs is an important step in determining which massive stars will explode and which will not. NGC6946 has an explosive history with a very high supernova rate, this makes the galaxy a great place to look for RSGs. We found 57 RSG candidates and estimated their ages by measuring the age of stars in their surrounding environment. Models suggest that 5-26 Million years (Myr) old RSG stars have masses of 10-30 times the mass of our sun. Our candidates returned ages ranging between 5-30 Myr with 24 of the candidates landing in the 10-20 Myr range. Comparing our measured ages and brightnesses to the models, many of our candidates appear to have properties consistent with the model predictions. However, the brightness of our candidates spans a larger range of brightness than the models for Spitzer would predict. We also find that four of our candidates are more consistent with models of two-star (binary) systems, making them good candidates for multiple star systems.

Progress in addressing the simultaneous demands for increasing speed and miniaturization in electrical and computer engineering is to its greatest extent bounded by material stresses under thermal shock. Higher speeds require higher power dissipation, and smaller unit volumes make adequate power dissipation more difficult to achieve. Although there already exists a large body of research concerning endpoint thermal failure in semiconductors, there is little research available on the topic of pre-failure behavior of circuit designs containing semiconductors. Our goal is to subject a circuit containing a semiconductor-based diode to the failure mechanism of thermal shock and test the conductivity of the circuit under drastically changing ambient thermal conditions. We will then use this data to experimentally determine any observable behaviors that qualify as pre-failure symptoms. The resulting observations will be used to determine the efficacy of simulation softwares like LTspice in predicting thermal behavior of a diode circuit under extreme and rapid temperature fluctuations. Our theory is circuit simulation softwares do not account for extreme ambient thermal changes. After completing statistical analysis we will compare the experimental results to simulated results of a duplicate circuit subjected to equivalent temperature parameters and determine if we can reject our theory.

When massive stars die, they explode in violent spectacles known as supernovae, specifically core-collapse supernovae. These cataclysmic events produce and distribute a large fraction of the heavy elements in the universe, but the properties of the massive stars that produce them have historically been difficult to measure. I have made new measurements constraining the masses of stars that have produced core-collapse supernovae, also known as supernova progenitors. I have done this by measuring the ages of stars at the location of supernova remnants: the nebulae of excited and enriched gas left behind by supernovae that have occurred over the past 20,000 years. Assuming the progenitor was associated with these stars, I am able to estimate the age of the star that exploded. Using theoretical models, I am able to infer the mass from this age. I used images taken by the Hubble Space Telescope to investigate the stars responsible for producing hundreds of these remnants in the nearby galaxy NGC 6946. In addition to the remnants of supernovae, this galaxy has hosted ten observed core-collapse supernovae within the past hundred years, leading to it being referred to as the “Fireworks Galaxy”. I was able to constrain the progenitor mass distribution for 175 remnants, eight of the historically observed supernovae, as well as the progenitor of the first direct black hole formation candidate in NGC 6946. I found the distribution of progenitor masses was consistent with mass distributions measured for massive stars in other galaxies, including our own Milky Way. These new measurements allow NGC6946 to be included for the first time in statistical studies of the masses of stars that produce supernovae.

I am furthering research in growing successful plant life in Martian regolith. The intention of this research is to amend Martian regolith so that it can support edible plant growth. We intend to counteract the characteristics that would impede plant growth and introduce low-mass additives that support plant growth. To simulate Martian ground “MMS-2” is used, this regolith is designed to be over 90% similar in chemical and textural composition to ground cover on Mars.Challenges noted from previous research include inhibited root growth, inefficient nutrient absorption, and impeded water uptake due to clay-like consistency. The additives selected to counteract these challenges include vermiculite to expand the soil and improve water circulation, and Biodyne™ microbes to enhance nutrient uptake. I chose to also incorporate mycorrhizal fungi to support and enhance root development and function. My previous research indicated that mycorrhizal fungi played a significant root development, plant height, and leaf growth. My current research is focusing on reproducing these results with more specimens and clear data points to further evaluate the impact of these additives. Rosemary was selected due to its ability to thrive in harsh, cold, and dry climates. As this plant is notoriously difficult to grow from seed, seeds were pre-sprouted to confirm viability prior to planting in the experimental pots in order to assure more specimens. Experimental regolith are treated with mycorrhizal fungi, Biodyne™, or both receive treatment mixed in water; all regolith and the control are based in a 30/70 earth soil to regolith blend with vermiculite. Plants treated with mycorrhizal fungi are anticipated to have darker and plentiful leaves; plants treated with Biodyne™ are anticipated to show straighter growth, plants treated with both are anticipated to be the most successful with both plentiful dark thick leaves and straight strong growth.

We are expanding previous research which manipulated the composition and chemistry of Mars regolith to better support plant life. The Mars regolith we are using is a 70% regolith 30% compost mix. Our focal plant for this experiment is Salvia rosmarinus (hereinafter rosemary) because of its resilience in cold climates and minimal water needs. Rosemary has been observed to have low germination success in both Earth soil and Mars regolith, to address this we sprouted seeds in water prior to transplant in order to guarantee seeds were viable rather than sowing rosemary directly in Mars regolith. We will ensure cotyledons have developed and stems have reached <5.0mm in length prior to transplanting in regolith to eliminate the variable of low seed viability. We hypothesize the amendments made to Mars regolith along with microbial and mycorrhizal additives will significantly improve rosemary development and growth. Plants we have previously attempted to grow in Mars regolith experienced difficulty establishing roots when transplanting cuttings and when grown from seed due to the clay-like consistency of the regolith. We have adjusted the previous experimental design by adding vermiculite to improve drainage and reduce regolith density, microbes to fixate Nitrogen and assist in nutrient uptake, and mycorrhizal fungi to encourage more effective root establishment and development. Previous experiments with Biodyne™ microbes and mycorrhizal fungi in Mars regolith have shown promising results in kale and rosemary. We anticipate the addition of Biodyne™ and mycorrhizal fungi, both independently and together, will improve root development, plant height, leaf growth, and chlorophyll richness. To test this, we will collect data bi-weekly by noting plant “greenness” and measuring plant height, leaf length, leaf count, and root growth.