The recently discovered minor body 1I/2017 U1 ('Oumuamua) is the first known object in our Solar System that is not bound by the Sun's gravity. Its hyperbolic orbit (eccentricity greater than unity) strongly suggests that it originated outside our Solar System; its red color is consistent with substantial space weathering experienced over a long interstellar journey. We carry out an simple calculation of the probability of detecting such an object. We find that the observed detection rate of 1I-like objects can be satisfied if the average mass of ejected material from nearby stars during the process of planetary formation is ∼20 Earth masses, similar to the expected value for our Solar System. The current detection rate of such interstellar interlopers is estimated to be 0.2/year, and the expected number of detections over the past few years is almost exactly one. When the Large Synoptic Survey Telescope begins its wide, fast, deep all-sky survey the detection rate will increase to 1/year. Those expected detections will provide further constraints on nearby planetary system formation through a better estimate of the number and properties of interstellar objects.

ABSTRACT. Three optical telescopes located at the San Pedro Mártir National Observatory were used for the first time to obtain multifilter defocused photometry of the transiting extrasolar planets WASP-39b and WASP-43b. We observed WASP-39b with the 2.12 m telescope in the U filter for the first time, and additional observations were carried out in the R and I filters using the 0.84 m telescope. WASP-43b was observed in V RI with the same instrument, and in the i filter with the robotic 1.50 m telescope. We reduced the data using different pipelines and performed aperture photometry with the help of custom routines in order to obtain the light curves. The fit of the light curves (1.5-2.5 mmag rms), and of the period analysis, allowed a revision of the orbital and physical parameters, revealing for WASP-39b a period (4:0552947 AE 9:65 × 10 À7 days) which is 3:084 AE 0:774 seconds larger than previously reported. Moreover, we find for WASP-43b a planet/star radius (0:1738 AE 0:0033) which is 0:01637 AE 0:00371 larger in the i filter with respect to previous works, and that should be confirmed with additional observations. Finally, we confirm no evidence of constant period variations in WASP-43b.

We present here the c-o colors for identified Flora, Vesta, Nysa-Polana, Themis, and Koronis family members within the historic data set (2015-2018) of the Asteroid Terrestrial-impact Last Alert System (ATLAS). The Themis and Koronis families are known to be relatively pure C-and S-type Bus-DeMeo taxonomic families, respectively, and the extracted color data from the ATLAS broadband c-and o-filters of these two families is used to demonstrate that the ATLAS c-o color is a sufficient parameter to distinguish between the C-and S-type taxonomies. The Vesta and Nysa-Polana families are known to display a mixture of taxonomies possibly due to Vesta's differentiated parent body origin and Nysa-Polana actually consisting of two nested families with differing taxonomies. Our data show that the Flora family also displays a large degree of taxonomic mixing and the data reveal a substantial H-magnitude dependence on color. We propose and exclude several interpretations for the observed taxonomic mix. Additionally, we extract rotation periods of all of the targets reported here and find good agreement with targets that have previously reported periods.