Figure 12 - uploaded by Wolfgang Steinicke
Content may be subject to copyright.
The spiral galaxy NGC 2903 in Leo, drawn by Lord Rosse on 5 March 1848 (after Parsons, 1850: Figure 3). The knot in the spiral arm is the conspicuous HII region NGC 2905, discovered by William Herschel in 1784.
Source publication
In April 1845 Lord Rosse discovered the spiral structure of M51 with his
72-inch reflector at Birr Castle. Already in March the new telescope
had been pointed at the object in Canes Venatici, later nicknamed the
'Whirlpool Nebula'. Two experienced astronomers were present: Sir James
South and the Reverend Thomas Romney Robin-son. The problem is tha...
Similar publications
Visually impaired people have difficulties in perceiving environmental information including the size of a space and the presence of objects, by means of visual information. Par-ticularly, auditory-trained visually impaired people can recognize 3-D spatial information by means of environmental sounds. However, a systematic learning method of audito...
Citations
... The galaxy pair M51 (NGC 5194/5) is perhaps the most iconic interacting system. It has been a subject of study since the 1800s, its spiral structure serving as a key element in early debates over the true nature of galaxies (Steinicke 2012). It has served, via simulations and observations, as an important dynamical benchmark for studies of tidal tails (e.g., Toomre & Toomre 1972;Burkhead 1978;Rots et al. 1990;Salo & Laurikainen 2000) and spiral density waves (e.g., Dobbs et al. 2010). ...
We present the discovery of a vast cloud of ionized gas 13$^{\prime}$ (32 kpc) north of the interacting system M51. We detected this cloud via deep narrow-band imaging with the Burrell Schmidt Telescope, where it appears as an extended, diffuse H$\alpha$-emitting feature with no embedded compact regions. The Cloud spans $\sim$10$^{\prime}\times$3$^{\prime}$ (25$\times$7.5 kpc) in size and has no stellar counterpart; comparisons with our previous deep broadband imaging show no detected continuum light to a limit of $\mu_{\rm lim, B} \sim$30 mag arcsec$^{-2}$. WIYN SparsePak observations confirm the cloud's kinematic association with M51, and the high NII/H$\alpha$, SII/H$\alpha$, and OI/H$\alpha$ line ratios we measure imply a hard ionization source such as AGN photoionization or shock heating rather than photoionization due to young stars. Given the strong NII emission, we infer roughly solar metallicity for the cloud, ruling out an origin due to infall of primordial gas. Instead we favor models where the gas has been expelled from the inner regions of the M51 system due to tidal stripping or starburst/AGN winds and has been subsequently ionized either by shocks or a fading AGN. This latter scenario raises the intriguing possibility that M51 may be the nearest example of an AGN fossil nebula or light echo, akin to the famous "Hanny's Voorwerp" in the IC 2497 system.
... Some of these telescopes and their users made significant contributions to science, in particular the 6-foot diameter µLeviathan of Parsonstown ¶ (e.g. see Steinicke, 2012) which was constructed in 1845 by the wealthy William Parsons, 3 rd Earl of Rosse (1800 ±1867). Parsons conducted many experiments on producing large telescopes, but his improvements were gradual. ...
Telescopes, reflecting telescopes in particular, underwent considerable
development during the eighteenth century. Two classes of telescope
maker, the for-profit artisan and the amateur 'gentleman-philosopher,'
learned techniques of optical fabrication and testing and produced
usable astronomical instruments. One means of disseminating technical
knowledge was via the book. The year 1738 saw the publication of a
highly-influential book, Robert Smith's A Compleat System of Opticks, a
work that included detailed information on telescope-making. It was
this book that helped spark the astronomical career of William Herschel,
and with Smith's information Herschel produced large reflecting
telescopes of exquisite quality. However, artisan-opticians, even the
renowned James Short, appear to have cut corners on a portion of their
production, thus permitting the sale of some instruments of inferior
quality. The reasons for this were clearly economical in nature:
artisans depending on telescope sales to earn a living simply could not
afford the time required for perfection. The mere presence of written
works disseminating technical
Argument
Keeping records has always been an essential part of science. Aside from natural history and the laboratory sciences, no other observational science reflects this activity of record-keeping better than astronomy. Central to this activity, historically speaking, are tools so mundane and common that they are easily overlooked; namely, the notebook and the pencil. One obvious function of these tools is clearly a mnemonic one. However, there are other relevant functions of paperwork that often go unnoticed. Among these, I argue, is the strategic use made of different procedures of record keeping to prolong observational time with a target object. Highlighting this function will help us to appreciate the supporting role played by the notebook and the pencil to extend the observational time spent with a target object. With objects as delicate, faint, and mysterious as the nebulae, the procedures used to record their observations helped nineteenth-century observers overcome the temporal handicaps and limitations of large and clumsy telescopes, mounted in the altazimuth manner. To demonstrate the importance of paper and pencil, I will closely examine the observing books, the drawings found therein, and the telescopes of three nineteenth-century observers of the nebulae: Sir John F. W. Herschel, Lord Rosse, and William Lassell.
We live in a universe filled with galaxies with an amazing variety of
sizes and shapes. One of the biggest challenges for astronomers working
in this field is to understand how all these types relate to each other
in the background of an expanding universe. Modern astronomical surveys
(like the Sloan Digital Sky Survey) have revolutionised this field of
astronomy, by providing vast numbers of galaxies to study. The sheer
size of the these databases made traditional visual classification of
the types galaxies impossible and in 2007 inspired the Galaxy Zoo
project (www.galaxyzoo.org); starting the largest ever scientific
collaboration by asking members of the public to help classify galaxies
by type and shape. Galaxy Zoo has since shown itself, in a series of now
more than 30 scientific papers, to be a fantastic database for the study
of galaxy evolution. In this Invited Discourse I spoke a little about
the historical background of our understanding of what galaxies are, of
galaxy classification, about our modern view of galaxies in the era of
large surveys. I finish with showcasing some of the contributions galaxy
classifications from the Galaxy Zoo project are making to our
understanding of galaxy evolution. This publication has been made
possible by the participation of more than 200,000 volunteers in the
Galaxy Zoo project. Their contributions are individually acknowledged at
http://www.galaxyzoo.org/volunteers. KLM acknowledges funding from the
Peter and Patricia Gruber Foundation as the 2008 Peter and Patricia
Gruber Foundation IAU Fellow, and from a 2010 Leverhulme Trust Early
Career Fellowship, as well as support from the Royal Astronomical
Society to attend the 28th GA of the IAU.
