Observing exoplanets with the MicroObservatory: 43 new transit light curves of the hot Jupiter HAT-P-32b

Observations of 43 complete transits of the hot Jupiter exoplanet HAT-P-32b using the MicroObservatory 0.15m robotic telescope network, covering a period of seven years, are presented. Compared with the most recent ephemeris for the system, the precision of the mid-transit times yields a root-mean-square value from the predicted model of 3.0min. The estimated system parameters based on EXOFAST modelling are broadly consistent with the default parameter values listed in the NASA Exoplanet Archive. An updated orbital period of 2.15000815 ± 0.00000013d and ephemeris of 2458881.71392 ± 0.00027BJDTDB are consistent with recent studies of the system using larger telescopes. Using this updated ephemeris, the predicted mid-transit time for a notional observation of HAT-P-32b by the NASA JWST mission in mid-2021 is improved by 1.4min compared with the discovery ephemeris and is approximately eight times more precise. Likewise, the mid-transit time for an observation by the ESA ARIEL mission in 2020 is improved by 1.7m

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J. H. Schröter & the ghost mountains of Venus

Since the invention of the telescope, observers of Venus have often reported irregularities in the shape of the planet’s terminator and cusps. Some of these, such as terminator undulations, might be easily ascribed to poor seeing conditions; others, such as cusp extensions near inferior conjunction, are undoubtedly real and evidence of Venus’s atmosphere. This paper considers a third category: detached points of light recorded by several observers at the cusps of the planet, explained by some as high mountain peaks catching the sunlight. Among those who argued for the existence of such mountains was Johann Schröter, a stance that brought him into conflict with the views of William Herschel. Nowadays the ‘ghost mountains of Venus’ are seen for what they are: an illusion encouraged by a growing belief in the plurality of Earth-like worlds.

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