Research Notes of the AAS
EISSN : 2515-5172
Published by: American Astronomical Society (10.3847)
Total articles ≅ 949
Latest articles in this journal
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac3253
In this note, I report a R-band polarimetric study on a massive star-forming region GL 437 (a.k.a. AFGL 437) to infer the magnetic field (B-field) geometry of this region. The mean B-field in the diffused region, is found to be parallel to the extended cloud structure and the Galactic plane. I compared present optical polarization results with archival submm results adapted from Curran & Chrysostomou. A flipped field geometry is seen in denser parts of GL 437 which is an interesting finding. An infrared source WK 34 embedded in the cloud is associated with a poorly collimated outflow. These outflows are parallel to the inner field orientation but misaligned with outer B-fields. An investigation of gas kinematics of this region will be carried out to understand if the gas motion have some role in changing the field geometry.
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac3256
We report second-timescale infrared photometry of the nova V1674 Her using Palomar Gattini-IR (PGIR). These observations constitute the first infrared and highest temporal resolution data (resolution of ≈0.84 s) of the nova reported to date. PGIR observed in this fast readout mode for more than an hour on three nights between 3 and 6 days after discovery. We searched for periodic variability using a Lomb–Scargle periodogram and did not detect anything down to a three sigma upper limit of 0.093 mag. This suggests that the periodic variability detected in the nova by Patterson et al. was lower by at least a factor of about 1.65 in the first week of the eruption.
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac324c
Impact craters are present on all bodies in the solar system with many displaying complex interior morphologies such as central peaks and central pits. Central peaks form due to the uplift of material in the center of the crater during transient crater formation while central pit formation has been suggested to occur by a number of processes including impacts into a weaker target which may contain volatiles. Comparing central peaks and central pits on rocky bodies like the Moon and Vesta will provide information about the formation processes of these morphologies on volatile poor bodies. In this study, we surveyed 248 craters on the Moon and Vesta. Our study of these central pits and central peaks suggest that crustal strength may contribute to the formation of central pits on rocky bodies and supports the notion that volatiles may not contribute to the formation of central pits on rocky bodies.
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac3255
HD 41004 is an unusual multiple star/planet system. Recent TESS photometry revealed a striking 31 hr period, far too short for the slowly rotating K dwarf primary. Instead, the modulation likely is from the diminutive dM secondary, spun-up to synchronous rotation by its close-in brown dwarf companion, and suffering intense magnetic activity as a result. If so, the red dwarf is perhaps destined to someday return the favor by cannibalizing its substellar partner.
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac313e
Quenching is the process by which a galaxy's star formation ceases and it moves from being a blue star-forming to a red quiescent galaxy. Concentration has been shown to be a good indicator of this process; this paper uses ΔΣ1 (a concentration offset derived below) to observe how quenching differs between galaxy morphologies. We use Sloan Digital Sky Survey data to plot ΔSFR against ΔΣ1, with morphological classifications from Galaxy Zoo 2 and environmental classifications from Yang et al. We find a difference in the distributions of concentration offset between early- and late-types that is not observed with differing environmental conditions and so conclude that separating the two allows more insight into their individual quenching processes. Late-types are shown to follow a process of compaction before then quenching and this is consistent with a picture where they quench slower than the early-types.
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac3086
Orbital resonance phenomena are notoriously difficult to communicate in words due to the complex dynamics arising from the interplay of gravity and orbital angular momentum. A well known example is Pluto's 3:2 mean motion resonance with Neptune. We have developed a python software tool to visualize the full three-dimensional aspects of Pluto's resonant orbital dynamics over time. The visualizations include still images and animated movies. By contrasting Pluto's resonant dynamics with the dynamics of a nearby non-resonant orbit, this tool enables better understanding and exploration of complex planetary dynamics phenomena.
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac2eef
We showcase a tool suite that enables the fitting of soft X-ray spectra in active galactic nuclei (AGNs), without the need for specialist software, allowing access to AGN physics for school students. While these standardized Python tools were useful for measuring velocities, they offered significantly fewer capabilities for radiative recombination continua, and R and G ratios, utilized to obtain the internal plasma properties within the outflowing wind seen in NGC 4151. Although further work is required for these tools to be used in outreach projects, we present findings of the plasma temperature and density in NGC 4151 spanning a 15 yr period.
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac2eee
We use Gaia EDR3 astrometry to propose that a dynamical interaction between the multiple system θ1 Ori C and θ1 Ori F ejected the latter as a walkaway star ∼1100 yr ago (without deceleration) or somewhat later (with a more likely deceleration included). It is unclear whether the final 3D velocity of θ1 Ori F will be large enough to escape the Orion nebula cluster.
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac2ef0
Research Notes of the AAS, Volume 5; https://doi.org/10.3847/2515-5172/ac2e6c
Two follow up observing sessions of Kepler's Eclipsing Binary star system EPIC 201458798 (from the K2 mission) were conducted in the Spring of 2018 and 2019 utilizing the 0.4 m subnet of the Los Cumbres Observatory Global Telescope network. The total duration of observations for each session (∼77 days) was comparable with the duration of observations by the Kepler telescope ∼80 days. 900–1000 images were obtained during each session with an integrating time around 1 minute, resulting in about 800 mag measurements per session. In contrast, the Kepler telescope provided almost continuous measurements of this star with an integration time per image of about 30 minutes, resulting in about 3250 photometric points. In contrast to the Kepler telescope measurements, which were conducted with one very broad filter, the observations in this study used four filters: B, V, ip, and rp. This data was processed and the period, time of minimum, and depth of the eclipses was determined. The results were compared with the data obtained by the Kepler telescope and other historical records.