A shout-out for small telescopes

R-band CCD image of Mrk 501 from ROVOR.

I think this quote from Napoleon Hill (essentially the “founder” of personal-success literature) is a good starting point for this post: “If you cannot do great things, do small things in a great way.” I think this applies wonderfully to many of the not-greater-than-1-meter telescopes.

My undergraduate project was to build and operate a remote observatory. The Remote Observatory for Variable Object Research, or ROVOR, was located about 2 hours away from the main campus of Brigham Young University (BYU). It is only a 16-inch telescope, but the main purpose of ROVOR was to be able to sit constantly on an object for a long period of time. For example, part of my capstone project was dissecting sixty days of observation on a single blazar—a compact galaxy with a very active supermassive black hole in its center pointed face-on at us—known as Markarian 501 (Mrk 501); we totaled more than eighty images of the galaxy per night, making observations about every 3 minutes (we had another project going on during the first half of the night, so we typically had about four hours of observations every night we observed). And the big question is, of course, why?

BYU's ROVOR in Delta, UT.

A lot of time, effort, and money have been placed into the development of large telescopes. They are important in studying extremely faint and distant objects. So, as a disclaimer, I am not at all against larger telescopes—they are needed desperately (even the Hubble Space Telescope is a 2.4-meter scope)! However, the emergence of the “small and simple” telescopes is quite important.

The availability of smaller telescopes allows individuals and smaller organizations (such as universities, community colleges, and high schools) to have a working telescope at their fingertips. This allows undergraduate students to sit on a single object for months on end. These smaller telescopes have opened the door to the time-domain portion of astronomy. Simply, the time-domain is evaluating the brightness of an object over long and short time periods. My undergraduate advisor, Dr. J. Ward Moody, discussed the importance of this aspect of astronomy almost daily.

Take the Kepler spacecraft as an example. It is a 0.95 m space telescope that has confirmed more than 240 planets around other stars! (The video shows an animation of the "confirmed" planets in their respective orbits around their companion sun.) Its discoveries were made possible by viewing one part of the sky for years. And the point of the mission: to “[stare] at the same star field for the entire mission and continuously and simultaneously [monitor] the brightesses of more than 100,000 stars for at least 3.5 years, the initial length of the mission…” (Kepler mission QuickGuide). The concept of Kepler was to look for small, intricate changes in the light curve (the brightness of a star over a period of time) of a hundred-thousand stars. By doing so, Kepler has been able to detect hundreds of otherwise-unobservable planets around other stars. The mission says that much more is coming—and not just in planet searches.

Columbia Basin College's REMO, in Richland, WA.

My undergraduate work with Mrk 501 was looking for changes in the light curve of this blazar, ranging from ∆t = 3 min to 3 months. In galactic astrophysics, the shorter times scale fluctuations correspond to the physical size and mass of the central supermassive black holes. So, in essence, we were searching for details that only constant, frequent observing would be able to find. Additionally, I worked with a community college in western Washington (Columbia Basin College) that was able to purchase a similar telescope to ROVOR (the Robert & Elisabeth Moore Observatory). The work they were interested in was transiting bodies—another time-domain project.

In conclusion, big telescopes are great—we all need them in our observing work. But small telescopes have a niche in the time-domain (and others, such as bright objects). They do small things great. If you need something looked at frequently and constantly, try finding a small group that has access to their own telescope. I know a few.