Printer Friendly

New jersey quasar quest: observing these exotic objects is easier than most people think.

Let's face it -- "dark-sky paradise" isn't the first phrase that comes to mind when you think of New Jersey. So a program to observe quasars visually from New Jersey might seem like a bad idea. Nonetheless, I've had a bug about seeing quasars with my own eyes since the first time I saw a photo of gravitationally lensed quasars 20 years ago. This article describes what happened when I finally got around to trying.

At 13th to 14th magnitude, even the brightest quasars are barely visible specks, but there's something appealing about the fact that old photons, crossing space over unimaginable distances and times, can end their long journey in my eye. And then there's the challenge of the hunt and the thrill of victory, as weird as that may sound when the victory consists of seeing a tiny speck of light.

A few years ago I got serious about making up a quasar observing program. The perfect starting point is 3C 273, some 2 billion light-years distant in the constellation Virgo. It's the brightest true quasar in the sky, varying slightly around magnitude 12.8. I saw it from light-polluted Princeton in my 10-inch Maksutov after a night or two, without much effort or suffering.

That whetted my appetite, and I began my program. Most of the others turned out to be much more challenging.

Making a List

The first step was to make a bright quasar observing list--which turned out to be much more difficult than I expected. Many online resources are available, but it's quite a challenge to sort through them. The same object may be listed under many different names, so it's wisest to identify quasars by their coordinates rather than their names. But even the coordinates vary slightly between sources, and one catalog may list an object as a quasar while another calls it a Seyfert galaxy (see the box on page 37).

I decided to start with the East Valley Astronomy Club (EVAC) online Quasar Observing Program. (The URL for this and all other online sources mentioned in this article can be found at It lists 48 quasars down to magnitude 14.99. I eliminated all entries fainter than magnitude 14.6 or south of declination 0[degrees] on the grounds that they're too low and/or faint to view easily from New Jersey.

I crossed-checked this with Wolfgang Steinicke's Catalogue of Bright Quasars and BL Lacertae Objects and investigated problematic entries with the SIMBAD Astronomical Database and the NASA/IPAC Extragalactic Database. I ended up eliminating some objects that are clearly not quasars at all, plus a few that turned out to be much fainter than the magnitudes listed on the EVAC website. That left 12 objects, which are listed on page 36. I have now successfully observed nine of those.

Photos and Maps

Many amateurs who are interested in trying this kind of project will have Go To mounts or computerized setting circles that will get them to the right general area in the sky, but that's just the first step when searching for a quasar. The problem is that almost all quasars look exactly like stars, and 14th-magnitude stars are so abundant that there are likely to be several near the center of your field of view.

To identify your target quasar, you need images that are centered precisely on the correct coordinates. The ones in this article were generated by combining the red and blue POSS-II plates from the Digitized Sky Survey (DSS); similar results can be obtained from WikiSky or the Aladin Sky Atlas.

I will admit to being a dinosaur -- I found the quasars by star-hopping, using DSS images and detailed maps. I started with the Uranometria 2000.0 Deep Sky Atlas, but that only shows stars down to 9th magnitude, so I supplemented it with detailed maps from a planetarium program. I included circles for the fields of the eyepieces I expected to use, and I printed the magnitudes of some of the stars on the maps so I could tell which star patterns I was looking at. (This is also useful because if you can't see nearby 13th-magnitude stars easily, then your quest for the quasar is doomed.) My highest-magnification maps typically show two to four times the field of view of my highest-power eyepiece.

Locations and Equipment

I looked for the quasars from my home in Princeton, New Jersey, and from the New Jersey Astronomical Association observatory site in Vorhees State Park, which is barely 50 miles west of New York City. According to the Clear Sky Chart website, these are in the red and orange light-pollution zones, respectively. (White is brightest, red next, and orange third on an 8-level scale.) I did see some of the quasars from Princeton, but I had better luck from Vorhees State Park.

I used two telescopes: a 10-inch f/20 Telescope Engineering Company (TEC) Maksutov, and a homemade 16-inch f/4.5 Dobsonian with a Meade mirror. Due to its tight star images, the 10-inch didn't do badly at all--I observed several of the quasars with it, even from Princeton. The 16-inch at the darker observing site was definitely better, though. Finder scopes were useful to get to the general area, but I usually used the main scope at its lowest possible magnification to narrow in on the location before switching to higher power. I needed at least 150 to see any of the quasars on the list, and I often used magnifications of 250 or even higher.

Wide-field eyepieces helped me identify the patterns of the field stars when observing at high power. For example, I used 12-mm and 7-mm Naglers in the 16-inch scope. My Maksutov has a drive, which was extremely helpful for this activity, but my 16-inch Dob does not. That made

it very difficult to star-hop at 250x while referring back and forth to maps -- I sometimes had to retrace my steps several times. It typically took at least an hour to get to the right spot and find the quasar, and sometimes even longer. I often spent several nights recording, sketching, and confirming an observation. Refusing to succumb to frustration was part of the "fun" of it.

The list on the facing page includes very brief observing notes. These may understate how challenging this is from New Jersey, but I'm sure that I saw the ones noted. For many of the quasars, even a small amount of sky haze was enough to kill them, and a quasar could be invisible on one night and then visible on another night.

Toward the end of the project, I realized that while most quasars vary a few tenths of a magnitude in bright-ness, some vary much more. 4C +29.45 should have been visible at its listed magnitude of 14.4, but I tried it five times without seeing it. Checking the Frankfurt Quasar Monitoring website, I discovered that this object (also called Ton 599) varies wildly on time scales ranging from minutes to years. It reaches 14th magnitude fairly often, but it's usually 15th or 16th magnitude, and it has been observed as faint as magnitude 18.5!

I personally plan to try to run through my list again now that I've had the mirror on my 16-inch refigured and I've psychologically recovered from all the fun of the first round of trying. I'll try for some of the quasars I missed, and maybe expand the list to include some fainter quasars. I hope that my experience inspires you to look for a few quasars yourself. Good hunting!

RELATED ARTICLE: What's a Quasar?

The word "quasar" was coined in 1964 as a short-hand for "quasistellar radio source"--a bright, concentrated radio source coinciding with an object that looks like a star but has a very high redshift, indicating that it's moving away from us at a huge speed. Today, the word is usually extended to include quasi-stellar objects (QSOs) that have the same visual properties as quasars, but aren't bright radio sources.

Astronomers soon realized that quasars have many features in common with Seyfert galaxies, which are galaxies that have hyperluminous nuclei with unusual spectral characteristics. According to current theory, Seyferts and quasars are part of the same continuum, members of the broader category of active galactic nuclei (AGNs).

AGNs are supermassive black holes surrounded by disks of matter (September 2013 issue, page 25). These accretion disks emit huge amounts of radiation as their material is pulled into the black hole. Many AGNs also shoot out jets at relativistic speeds.

Quasars are probably just like the nuclei of Seyfert galaxies except that they're brighter--often 100 times more luminous than all the host galaxy's stars combined. But the dividing line between quasars and Seyferts is arbitrary. All the objects in our list have been classified as quasars in one or more studies, but if you look at images of UGC 545 and RX J23273+1524, you will see that both of them have prominent galactic disks as well as pointlike nuclei. Most astronomers would probably classify RX J23273+1524 as a Seyfert and UGC 545 as a borderline case.

4C +29.45 (also known as Ton 599) is a blazar, a quasar whose jet points straight at us, making it appear much more luminous than it would if the jet were aimed in a different direction. Blazars are characterized by extreme variability, sometimes brightening or dimming by a full magnitude in a single day.

See S&T April 2010, page 70, for other blazars observable through backyard telescopes.

--Tony Flanders

Bob Cava is a professor of chemistry at Princeton University specializing in high-temperature superconductors.

Star Groups and Nebulae in the Celestial Twins

Object    Type       Mag(v)   Size       RA          Dec.

M35       Open          5.1    28'  6h 09.0  +24[degrees]
          cluster                         m           21'

NGC 2158  Open          8.6     8'  6h 07.4  +24[degrees]
          cluster                         m           06'

NGC 2129  Open          6.7     7'  6h 01.1  +23[degrees]
          cluster                         m           19'

Ferrero   Asterism       --    17'  6h 15.4  +25[degrees]
18                                        m           30'

IC 443    Supernova       9  50' x  6h 16.8  +22[degrees]
          remnant              40'        m           31'

HoCr 1    Probable       --   73"x  6h 21.7  +23[degrees]
          planetary            59"        m           35'

J900      Planetary    11.7     9"  6h 26.0  +17[degrees]
          nebula                          m           47'

Angular sizes and separations are from recent catalogs.
Visually, an object's size is often smaller than the
cataloged value and varies according to the aperture and
magnification of the viewing instrument. Right ascension
and declination are for equinox 2000.0.
COPYRIGHT 2014 All rights reserved. This copyrighted material is duplicated by arrangement with Gale and may not be redistributed in any form without written permission from Sky & Telescope Media, LLC.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2014 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Hunting Distant Objects
Author:Cava, Bob
Publication:Sky & Telescope
Geographic Code:1U2NJ
Date:Mar 1, 2014
Previous Article:Regulus over new york.
Next Article:What's a quasar?

Terms of use | Privacy policy | Copyright © 2022 Farlex, Inc. | Feedback | For webmasters |