It's cloudy and cold. Your astro-buddies all are out of town, observing. You've already read all your astronomy magazines, twice. What are you going to do tonight?
The World Wide Web has many excellent resources for professional astronomers. As a professional astronomer, it pains me when my amateur friends tell me they're never heard of them. Many should prove extremely useful for amateurs, and perhaps in ways not originally intended.
The web page I use most in my day-to-day research is:
The NASA Astrophysics Data System.
I still prefer the Classic Form .
Type in the name of an astronomical object, an author name, or words in the title or text of a paper, in the appropriate boxes. ADS will list the scientific papers on the specified object, or by the specified author. These papers are in a wide range of refereed journals, unrefereed journals, and popular-level magazines. (The referees are other professional astronomers, asked by the journals to read the manuscripts carefully, check for errors, and report on whether the papers should be published. The refereeing process isn't infallible, referees being human, but it does help the quality of many papers—at least, it has for several of mine!)
ADS can also search with keywords. These can yield long lists of papers, but ADS has logical functions for narrowing searches. ADS lists go surprisingly far back in time. A search of unrefereed or refereed papers using the name "Struve" listed over 1100 items. Most of these were by Otto Struve, including 252 refereed papers he published between 1942 and 1963 in the Astrophysical Journal, as well as 167 articles in the popular-level magazine, Sky & Telescope. However, the oldest reference turned up in the the general search on "Struve" was the 1813 Ph.D. thesis of his great-grandfather, Friedrich Georg Wilhelm von Struve. ADS also has page images of many refereed journals, since 1980.
Another web resource I use nearly every day is the SIMBAD astronomical database. SIMBAD stands for Set of Identifications, Measurements, and Bibliography for Astronomical Data. It's run by the Centre de Données astronomiques de Strasbourg (CDS, Strasbourg), in France.
SIMBAD contains information for 13.5 million objects, including over 53 million identifiers, and 400,000 bibliographical references. It's great for cross-references, for example if you know an object's Messier number, but want to know its NGC number, or if you know a star's SAO or HD number, but want to know its HR number---or name.
SIMBAD also lists nearly all papers in refereed and other journals, as far back as 1850. It can search on an object's name you type in, or by equatorial coordinates (right ascension and declinations): the default search radius is 10 arcminutes. SIMBAD is available on the web:
SIMBAD can also be used in batch mode, for complex or long searches.
Another useful database is NED, the NASA/IPAC Extragalactic Database. It can find objects at a given set of equatorial coordinates, much as how SIMBAD does. It also has a number of useful utilities. One I often use is the Coordinate Transformation & Extinction Calculator. This converts equatorial coordinates (right ascension and declination) to galactic coordinates (galactic longitude and latitude) and inverse. It can also precess coordinates, or convert them from a user-specified equinox and epoch to 1950 or 2000 coordinates. It also calculates the amount of extinction and reddening due to interstellar dust at any set of coordinates, by comparing them with detailed maps of dust in the Milky Way. NED also has several cosmology calculators, to calculate how far away and how old galaxies are, given various models of the expansion of the Universe.
In the 1960s, a good finding chart of an important object was almost enough to justify a publication by itself. Things have improved since, with:
SkyView: The internet's Virtual Telescope
SkyView makes finding charts. All you need to do is to type in an object's name. SkyView is connected to SIMBAD, and if SIMBAD can match this name, SkyView finds the object's coordinates and returns this to SkyView. You may also type equatorial coordinates directly into SkyView.
SkyView then returns a square image, of default size 8.5 arcminutes on a side. Skyview includes sky maps in many wavelengths of light, from radio to gamma rays: selecting "Digitized Sky Survey" will show images in visible light. These reach fainter than 20th magnitude in the red (E) or green (J) bands. (The limiting magnitude varies from field to field, but detailed calibrations are available). These images were scanned from wide-field photographs, taken during the Palomar Observatory Sky Survey, and by the Southern Sky Survey, carried out by the Royal Observatory, Edinburgh and Anglo-Australian Observatory. No more fumbling through the library for finding charts!
Try it yourself. Bring up the Basic interface, and type the Messier or NGC number of one of your favorite deep-sky objects, such as NGC 891 or M13 (and be sure to select "Digitized Sky Survey"). You can download the images in ("quick-look") jpeg, a well-known image format, or more detailed images in FITS format, the standard image format in professional astronomy, or even in compressed FITS, which can be uncompressed with the UNIX "uncompress" program. To fit large objects, such as M42 or M31, into the frame, you need to reset the image size. Large frames can take a while to load, regardless of image format. Still, SkyView's potential is clear, especially for owners of CCDs.
Space Telescope Science Institute (STScI) is in Baltimore, on the campus of John Hopkins University. STScI runs James Webb Space Telescope and Hubble Space Telescope. Of course they have a web page, of interest to users and general public alike, at:
Space Telescope Science Institute Home Page
STScI has a splendid image archive, press releases to go with it, and many pages of education and public-outreach activities.
Most other space missions run their own pages, too. You can usually find them by typing the mission name or abbreviation into any internet search engine such as Google or Bing, two examples being Mars Perseverance Rover and Chandra X-ray Observatory.
A large list by NASA of operating, planned, and past science missions is:
NASA is a government agency. The data from its spacecraft therefore go into the public domain. Anyone can access these data, often consisting of quite tasty images that were glanced at once, but were since forgotten. Even now, years after many of the missions, these space datasets could stand serious look-throughs. Patient amateurs, unbothered by imminent grant proposal deadlines, often excel at this.
For searching through the databases from spacecraft, there is:
MAST: Barbara A. Mikulski Archive for Space Telescopes
Barbara Mikulski was the U.S. Senator who saved Hubble Space Telescope from cancellation, when it was found to have serious problems with its optics when it was launched in 1990, which were fixed by Space Shuttle astronauts in 1993.
There are whole astronomical data centers that do this, too. One is at NASA Goddard Space Flight Center, NASA's center for space science:
NASA Space Science Data Coordinated Archive
NSSDCA acts as a clearinghouse for data from astrophysics, space physics, solar physics, and planetary missions. Of greatest interest to the general public user is:
Resources are now available not only for visible ligt, but for every part of the electromagnetic spectrum:
High Energy Astrophysics Science Archive Research Center (HEASARC), for X-ray and gamma-ray astronomy,
MAST: Barbara A. Mikulski Archive for Space Telescopes, largely for ultraviolet and visible-light,
National Optical-Infrared Astronomy Research Laboratory
(NOIRLab),
formerly the National Optical Astronomy
Observatories (NOAO) and the Gemini Observatories,
IPAC, the Science & Data Center for Astrophysics & Planetary Sciences, formerly the Infrared Processing and Analysis Center,
National Radio Astronomy Observatory (NRAO)
Astropy is free image processing software in Python. Astropy has replaced IRAF, the image processing package that was supported by the national observaories (NOAO) from 1986 to 2019, and was notorious for its steep learning curve. The Astropy project's astropy/astropy Astronomy and astrophysics core library is available the GitHub, a software repository who call themselves, "The world's leading softwware development platform." You can find all manner of software for astronomy and astrphysics here.
A solar resource, with links to others, is the Solar Data Analysis Center (SDAC) at NASA Goddard Space Flight Center:
Another source of current solar images from various solar observatories and spacecraft is:
This is one of my favorite pages. It's fascinating to watch sunspots march, prominences leap, and coronal streamers dance, from day to day. It's quite safe, too, since all you need do is look at your computer screen!
Solar flares and sunspots are only two small parts of space weather. For current conditions in the solar wind, coronal holes, geomagnetic storms and aurorae, as well as meteor rates and asteroids, see:
Sunspot numbers and the solar cycle progression are here:
Space Weather Prediction Center
An outstanding resource for eclipses is:
MrEclipse is Fred Espenak, who retired from NASA but his webpage is still here:
NASA's new website for eclispes is:
Professional astronomers publish in refereed journals. As soon as their papers are accepted, they send advance copies ("preprints") to:
A list of astronomy meetings is compiled by the staff of the Canada-France-Hawaii Telescope, at:
International Astronomy Meetings
A famous source of fast-breaking news, of anything in the sky that varies or moves (including, but not limited to, novae, supernovae, gamma ray bursts, comets, asteroids), and much else, is:
The Central Bureau for Astronomical Telegrams
Another source of fast-breaking news, especially for transient sources, is here:
Participation by serious, careful amateurs has always been welcome, and is
increasing. Unfortunately, since anyone can send e-mail these days, so is
the number of false alarms. The directors of CBAT do not take kindly to
these---nor do the thousands of professional and amateur observers who
subscribe to the International Astronomical Union (IAU) Circulars that
CBAT issues by e-mail. False alarms almost never get past the directors
of CBAT, but their jobs are hard enough: be sure to do both those checks
before reporting!
A global network of small telescopes dedicated to photometry of cataclysmic variable binary stars, run by professional astronomers but largely composed of amateur observers, is:
Center for Backyard Astrophysics
Amateurs often produce useful science observations, if they are careful, even with modest equipment. Many professional observers who organize amateur observing campaigns. Some include:
The American Association of Variable Star Observers
Association of Lunar & Planetary Observers (ALPO)
The International Occultation Timing Association (IOTA)
The web has many utilities for observing. Accurate time is kept at:
The Official National Institute of Standards and Technology (NIST) Clock
This includes Local Standard or Daylight Time for U.S. time zones, Universal Time, and Local Apparent Sidereal Time.
NIST is the civilian arm of the U.S. Naval Observatory. They have a number of other resources for timekeeping, including:
Data
Services, including Sun and Moon rise and set times, Moon phases,
eclipses, seasons, positions of solar system objects, and other data
There are many fine weather pages. One specifically for astronomers is:
One, with all manner of satellite images, is:
Yet another, by the National Center for Atmospheric Research, is:
One I particularly like, from the National Oceanic and Atmospheric Administration (NOAA), is the:
Geostationary Satellite Server
A weather page that can be customized to your site, and also contains astronomical data, is:
And of course, there are countless other pages by organizations and individual astronomers, many of them frighteningly useful. There's a whole Universe of information out there. Happy exploring!
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Professor Ringwald is on the faculty at California State Unversity, Fresno.
His web page is at:
http://zimmer.csufresno.edu/~fringwal/index.html
Example 2. If you set your browser to SkyView (http://skyview.gsfc.nasa.gov/skyview.html), select the "Basic" interface, select the "Digitized Sky Survey" in the "Survey" box, type "NGC 891" into the "Coordinates or Source" box, and click on "Submit", this image will be displayed, which you can download in gif, FITS, or compressed FITS image format. Try it yourself!
Last updated 2022 September 26. Web page by Professor Ringwald (ringwald[at]csufresno.edu and replace [at] with @) and Amanda Race.
