Nature's Astronomical Highlights
The journal Nature has been at the pinnacle of scientific publishing for many years. Founded by an astronomer, Norman Lockyer, it has had an extensive history in publishing the most significant developments in the Natural Sciences. For instance, James Chadwick published his discovery of the neutron in Nature; James Watson and Francis Crick presented the helical structure of DNA. Naturally, astronomy has been no exception: part of the discussion following the “Great Debate” on the nature of the Spiral Nebulae (were these small nebulae within our Galaxy or distant galaxies in their own right?) was contained in Nature’s pages in the early 1920s. In the 1960s, Maarten Schmidt’s discovery of the first quasar and Antony Hewish & Jocelyn Bell’s discovery of the first pulsar were presented in Nature. Even up until the present day, Nature is publishing discoveries that not only are of great interest to professional and amateur astronomers and astrophysicists, but also of relevance to humankind in general. In 2016 we discovered through the work of Guillem Anglada-Escudé and collaborators that the nearest star to our Solar System harbours a rocky planet in a temperate orbit.
It is on the back of these discoveries and this extensive history that Nature Research is launching a new journal in 2017, Nature Astronomy, so that more astronomical research might be published with a similar high standard of editing, peer review and production as Nature’s. To celebrate Nature’s comprehensive astronomical heritage, we at Nature Astronomy have curated this Web Collection of 40 Nature papers that have had significant impact on astronomical research. Several of these papers have been cited over 1,000 times in the astronomical literature. To include some more recent papers, which have not had the luxury of many years over which to accrue citations, we have also consulted Altmetric scores, which gauge social media impact among other things. The result is a Collection of Letters, Articles and Reviews that have been roughly grouped into seven themes: exoplanets, pulsars, black holes & short gamma-ray bursts, long gamma-ray bursts & supernovae, galaxies, dark matter and the large-scale structure of the Universe. Several of these papers have been selected for Free Access for a limited period; these can be found collected together below, or in the “Free access” tab, above.
Before we delve into these seven topics, there is one stimulating paper that stands apart, written by astronomer and science communicator Carl Sagan and his colleagues (Sagan et al. 1993). It details an experiment performed with the Galileo spacecraft on its way to Jupiter. Galileo was commanded to turn towards the Earth, and capture data with its instruments. Effectively it observed the Earth for signs of life. However, it only just managed to find them: it saw a water-rich atmosphere and surface; it saw signs of biological activity in the high levels of methane; it saw a red-absorbing pigment that might have been responsible for photosynthesis; but the only compelling and indicative detection was that of narrow-band radio emission suggestive of a technological civilisation. The paper presented a unique opportunity to objectively observe our blue marble planet from afar.
Pulsars are the decayed carcasses of massive stars, which sweep a beam of electromagnetic radiation across the Earth as they rotate. The existence of neutron stars was postulated in the 1930s by Walter Baade and Fritz Zwicky, but it wasn’t until 1967 that Franco Pacini, writing in Nature, theorised that a rotating neutron star with a magnetic field would emit a beam of light that could be detected – a pulsar (Pacini 1967). The following year Jocelyn Bell, Antony Hewish and three other colleagues discovered such a signal, although they did not realise it at the time, dubbing their pulsing radio source ‘LGM-1’ for ‘Little Green Men’ (Hewish et al. 1968). It was Thomas Gold, also writing in Nature, who put two and two together, connecting Bell & Hewish’s Little Green Men signal with a theory of neutron star lighthouses similar to that of Pacini’s (Gold 1968). Hewish’s discovery eventually led to the 1974 Nobel Prize in Physics.
In the early 1980s a new regime of pulsar astronomy opened up with the discovery of a pulsar with a period of just over one millisecond. Don Backer (Backer et al. 1982) brought significant insight into this burgeoning field by postulating that these pulsars, despite being very energetic and rotating rapidly, were old objects rather than young. He also suggested that the reason they were rotating so quickly was due to the presence of a binary companion spinning up the aged neutron star.
More recently Paul Demorest and colleagues (Demorest et al. 2010) studied a millisecond pulsar in order to establish the mass of a neutron star. By measuring the increase in light-travel time for radio waves emitted from the pulsar as it passed through the curved space-time near the white dwarf companion, they calculated a mass of ~2 solar masses. This put a much-needed empirical constraint on the Tolman-Oppenheimer-Volkoff limit (the maximum mass of a neutron star, equivalent to the Chandrasekhar limit for white dwarf stars), which was thought at the time to be somewhere between 1.5 and 3 solar masses. They also used these measurements to rule out various equations of state for the neutron star.
