![]() Further, the planet discovered around 47 Ursae Majoris 8 seems quite ‘normal’, having a minimum mass of 2.5 Jupiter masses and orbiting at 2.1 Earth-Sun distances in a nearly circular orbit. Their number and variety provide a powerful argument against quirky explanations for any individual detection. But all of the above threats to the planet interpretation lose strength in the face of the seven additional planetary companions since discovered around other stars (see Table 1). Instead, we can tell that the star rotates roughly once every 30 days, based on its weak magnetic field - not much different from that of the Sun. For example, the brown dwarf would raise tides on the primary star, and so exert a torque that would spin-up 51 Peg to a 4-day rotation period. But some of them can be rejected by astrophysical reasoning. This plethora of interpretations represents science at its healthiest. The empirical case for oscillations has vanished, leaving planets as the only plausible interpretation. But now, three papers 3, 4, 5 (including those on page 153 and page 154 of this issue) report that the spectral evidence of pulsations is absent, after all. This interpretation called into question the reality of not just the 51 Peg planet, but also the other five detected extrasolar planets, as highlighted by the cover of Nature (27 February 1997): “Extrasolar planets: Fading from view”. But criticism of this interpretation came from David Gray 2, who reported spectral-line variations that could be caused only by an undulating, pulsating stellar surface, not an orbiting planet. The original suggestion 1 that a planet exists around the star 51 Pegasi was based on periodic variations in Doppler shifts of the light from the star - presumably caused by wobbling because of the gravitational pull of the planet. Send us feedback about these examples.Last year a conflagration of controversy engulfed the first planet ever claimed around a Sun-like star now it has suddenly been extinguished, leaving the new world unscathed. These examples are programmatically compiled from various online sources to illustrate current usage of the word 'periodic.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Amber Smith, Discover Magazine, 15 Aug. 2023 This can be done by spacing out your usage or taking periodic breaks altogether. 2023 Even periodic crises in Washington have failed to dislodge global confidence in the dollar. 2023 The program also includes an annual membership to The Regeneration Project where periodic diagnostics continue year-round to help guests stay on track. 2023 The bolts can be replaced, loosened or tightened during repairs or periodic rebuilding and replacement of parts. ![]() Chris Vognar, Los Angeles Times, 5 Sep. 2023 On both a personal and a political level, the Naomi conflation went from periodic annoyance to existential dilemma. 2023 Whether from a mental health disorder or periodic stress, managing anxiety-and learning ways to fall back asleep-can be a critical part of maintaining your overall health. 2023 More than 2 million migrant entries were recorded in each of the last two years, creating periodic scenes of chaos in border towns. Recent Examples on the Web Pfeffer said that for years, Israeli politicians have, despite periodic rounds of violence with militants from Hamas and Islamic Jihad, relegated Gaza to the periphery of their concerns.
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