APRIL 2010 OBSERVER Inside the Unchained Melody Observer
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Visual Astronomy Filter Research
Visual Astronomy Filter Research by Jim Thompson, P.Eng May 2010 Table of Contents: 1.0 The Great Filter Filibuster ...................................................................................... 3 2.0 The Human Eye...................................................................................................... 5 3.0 Planetary (Colour) Filter Research ......................................................................... 7 4.0 Using Planetary (Colour) Filters........................................................................... 12 5.0 Deep-Sky (Band Pass) Filter Research................................................................. 21 6.0 Using Deep-Sky (Band Pass) Filters..................................................................... 25 7.0 References............................................................................................................. 33 Appendix A – Colour Filter Plots ..................................................................................... 36 Appendix B – Deepsky Filter Plots .................................................................................. 43 List of Figures: Figure 1 An assortment of planetary (colour) filters ...................................................... 3 Figure 2 An example of deep-sky (band-pass) filters..................................................... 4 Figure 3 Human Eye Rod & Cone Density Distribution ................................................ 5 Figure 4 Human Eye Spectral Sensitivity...................................................................... -
Science Goals and Selection Criteria
University of Groningen The ATLAS(3D) project Cappellari, Michele; Emsellem, Eric; Krajnovic, Davor; McDermid, Richard M.; Scott, Nicholas; Kleijn, G. A. Verdoes; Young, Lisa M.; Alatalo, Katherine; Bacon, R.; Blitz, Leo Published in: Monthly Notices of the Royal Astronomical Society DOI: 10.1111/j.1365-2966.2010.18174.x IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Publisher's PDF, also known as Version of record Publication date: 2011 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Cappellari, M., Emsellem, E., Krajnovic, D., McDermid, R. M., Scott, N., Kleijn, G. A. V., Young, L. M., Alatalo, K., Bacon, R., Blitz, L., Bois, M., Bournaud, F., Bureau, M., Davies, R. L., Davis, T. A., de Zeeuw, P. T., Duc, P-A., Khochfar, S., Kuntschner, H., ... Weijmans, A-M. (2011). The ATLAS(3D) project: I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria. Monthly Notices of the Royal Astronomical Society, 413(2), 813-836. https://doi.org/10.1111/j.1365- 2966.2010.18174.x Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license. -
Filter Performance Comparisons for Some Common Nebulae
Filter Performance Comparisons For Some Common Nebulae By Dave Knisely Light Pollution and various “nebula” filters have been around since the late 1970’s, and amateurs have been using them ever since to bring out detail (and even some objects) which were difficult to impossible to see before in modest apertures. When I started using them in the early 1980’s, specific information about which filter might work on a given object (or even whether certain filters were useful at all) was often hard to come by. Even those accounts that were available often had incomplete or inaccurate information. Getting some observational experience with the Lumicon line of filters helped, but there were still some unanswered questions. I wondered how the various filters would rank on- average against each other for a large number of objects, and whether there was a “best overall” filter. In particular, I also wondered if the much-maligned H-Beta filter was useful on more objects than the two or three targets most often mentioned in publications. In the summer of 1999, I decided to begin some more comprehensive observations to try and answer these questions and determine how to best use these filters overall. I formulated a basic survey covering a moderate number of emission and planetary nebulae to obtain some statistics on filter performance to try to address the following questions: 1. How do the various filter types compare as to what (on average) they show on a given nebula? 2. Is there one overall “best” nebula filter which will work on the largest number of objects? 3. -
Craters in Shadow
Section 3: Craters in Shadow Kepler Copernicus Eratosthenes Seen it Clavius Seen it Section 3: Craters in Shadow Visibility: A pair of binoculars is the minimum requirement to see these features. When: Look for them when the terminator’s close by, typically a day before last quarter. Not all craters are best seen when the Sun is high in the lunar sky - in fact most aren’t! If craters aren’t par- ticularly bright or dark, they tend to disappear into the background when the Moon’s phase is close to full. These craters are best seen when the ‘terminator’ is nearby, or when the Sun is low in the lunar sky as seen from the crater. This causes oblique lighting to fall on the crater and create exaggerated shadows. Ultimately, this makes the crater look more dramatic and easier to see. We’ll use this effect for the next section on lunar mountains, but before we do, there are a couple of craters that we’d like to bring to your attention. Actually, the Moon is covered with a whole host of wonderful craters that look amazing when the lighting is oblique. During the summer and into the early autumn, it’s the later phases of the Moon are best positioned in the sky - the phases following full Moon. Unfortunately, this means viewing in the early hours but don’t worry as we’ve kept things simple. We just want to give you a taste of what a shadowed crater looks like for this marathon, so the going here is really pretty easy! First, locate the two craters Kepler and Copernicus which were marathon targets pointed out in Section 2. -
The Young Nuclear Stellar Disc in the SB0 Galaxy NGC 1023
MNRAS 457, 1198–1207 (2016) doi:10.1093/mnras/stv2864 The young nuclear stellar disc in the SB0 galaxy NGC 1023 E. M. Corsini,1,2‹ L. Morelli,1,2 N. Pastorello,3 E. Dalla Bonta,` 1,2 A. Pizzella1,2 and E. Portaluri2 1Dipartimento di Fisica e Astronomia ‘G. Galilei’, Universita` di Padova, vicolo dell’Osservatorio 3, I-35122 Padova, Italy 2INAF–Osservatorio Astronomico di Padova, vicolo dell’Osservatorio 5, I-35122 Padova, Italy 3Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122, Australia Accepted 2015 December 3. Received 2015 November 5; in original form 2015 September 11 Downloaded from ABSTRACT Small kinematically decoupled stellar discs with scalelengths of a few tens of parsec are known to reside in the centre of galaxies. Different mechanisms have been proposed to explain how they form, including gas dissipation and merging of globular clusters. Using archival Hubble Space Telescope imaging and ground-based integral-field spectroscopy, we investigated the http://mnras.oxfordjournals.org/ structure and stellar populations of the nuclear stellar disc hosted in the interacting SB0 galaxy NGC 1023. The stars of the nuclear disc are remarkably younger and more metal rich with respect to the host bulge. These findings support a scenario in which the nuclear disc is the end result of star formation in metal enriched gas piled up in the galaxy centre. The gas can be of either internal or external origin, i.e. from either the main disc of NGC 1023 or the nearby satellite galaxy NGC 1023A. The dissipationless formation of the nuclear disc from already formed stars, through the migration and accretion of star clusters into the galactic centre, is rejected. -