Reconstructing Past Solar Activity using Meridian Solar Observations: the Case of the Royal Observatory of the Spanish Navy (1833-1840)
arXiv:1401.4501 · doi:10.1016/j.asr.2014.01.015
Abstract
Solar meridian observations have been used to evaluate the solar activity of the past. Some important examples are the solar meridian observations made at the Basilica of San Petronio in Bologna by several astronomers and the observations made by Hevelius published in his book Machina Coelestis. However, we do not know whether these observations, which were not aimed to estimate the solar activity, are reliable for evaluating solar activity. In this paper, we present the marginal notes about sunspots that are included in the manuscripts of the meridian solar observations made at the Royal Observatory of the Spanish Navy during the period 1833-1840. We compare these observations with other solar activity indices such as sunspot area and number. Our conclusion is that solar meridian observations should be used with extreme caution to evaluate past solar activity.
14 pages, 4 figures, accepted for publication in Advances in Space Research
References in corpus (1)
Cited by in corpus (12)
- Revisiting the Sunspot Number
- The Maunder minimum (1645--1715) was indeed a Grand minimum: A reassessment of multiple datasets
- A Revised Collection of Sunspot Group Numbers
- Thaddäus Derfflinger's sunspot observations during 1802-1824: A primary reference to understand the Dalton Minimum
- Sunspots during the Maunder Minimum from Machina Coelestis by Hevelius
- Sunspot characteristics at the onset of the Maunder Minimum based on the observations of Hevelius
- Sunspot Observations during the Maunder Minimum from the Correspondence of John Flamsteed
- Strong evidence of low levels of solar activity during the Maunder Minimum
- The umbra-penumbra area ratio of sunspots during the Maunder Minimum
- Monitoring the Solar Radius from the Royal Observatory of the Spanish Navy during the Last Quarter-Millennium
- Comparison of solar activity proxies: eigen vectors versus averaged sunspot numbers
- Could a Hexagonal Sunspot Have Been Observed During the Maunder Minimum?