Ted Forte is a contributing editor at Sky and Telescope and coordinator for the Astronomical League’s Planetary Nebula Program. Julian Samuel, a beginner amateur astronomer, artist and writer, interviewed Forte in late 2021 via email.
Julian Samuel, SkyNews: I setup my telescope a few hours before the cerulean blue sky darkens. Sometimes, a whitish half Moon hangs in this blue field which triggers immense excitement for viewing the planets, stars and clusters. How do you find the short period before observing?
Ted Forte: After decades of doing amateur astronomy, one can’t help but become more mechanical about it. A lot of the emotional impact becomes dulled by familiarity. I don’t often experience that sense of eager anticipation that once accompanied twilight. That’s not to say that I don’t enjoy the slow transformation as evening gives way to night and the first stars (or planets) emerge. I do. It’s always a quiet, pleasant, contemplative time, but it’s one that I don’t always encounter. The wee hours are my favourite time to observe and it is my usual habit to venture out to the scope around midnight or later (after an evening nap) and sometimes observe until morning twilight. So, you could say I am more apt to mourn the slow departure of night than anticipate its arrival. Dawn, however, does leave me with a feeling of accomplishment and satisfaction.
JS: Do you set targets thematically or you sometimes find yourself drifting from one beauteous object to another?
TF: I save the “drift from one beauteous object to another” routine for my outreach events these days. I spend a great deal of time doing public events and showing people around the sky. That’s when I view the Moon, the planets and the bright showpiece objects. I think doing outreach, revealing the sky’s wonders to the uninitiated, is probably my favourite thing to do with a telescope! I also get plenty of opportunities to observe the brighter objects when observing with other astronomers at star parties.
The time I spend observing alone is typically spent in pursuit of those faint fuzzies that stretch to the limits of detection.
JS: Does a particular deep-sky object determine which aperture telescope you’ll use?
TF: It’s sort of the other way around. The telescope I choose often determines the type of observing I do. My primary telescope these days is a 30-inch Dobsonian housed in a large roll-off roof observatory. It is motor driven and computer controlled, and I use it to reach those 15th and 16th magnitude targets that are not accessible to my smaller telescopes. It’s a bit of an operation to open the roof and prepare the big scope, so I reserve it for the best nights, without any cloud, or wind, or moon.
My backup is an 18-inch Dobsonian which can be used as a Go-To, a push-to, or without any pointing aids at all and the configuration I use is a matter of whim. It is my favourite scope, and it is a comfortable scope to star hop with. I sometimes just want the simplicity of rolling that scope into the yard and observing without the complications of technology, observing plans, or even charts. Just the scope, a ladder and one eyepiece: a 12mm Type 4 Nagler, that with a Paracorr, yields 197× with a 25′ field of view. That’s when I “drift from one beauteous object to another,” as you put it.
I do all of my “new” objects with the 30-inch and return to the favourites like the Messiers and the planets with the smaller scopes. I also use a 10-inch Dob, an 8-inch SCT, and a 4-inch Takahashi refractor. The 10-inch Dob is the scope I most often use at outreach and I enjoy star hopping with it. The SCT was, for about a decade, my primary scope, but these days I mostly use it for the Sun – with a full aperture white light filter and a Coronado PST Hydrogen-alpha scope riding “piggy-back” atop it.
JS: In the Sky and Telescope of August 2021 (“Observing the Pegasus I Galaxy Cluster”) you open thusly:
On September 26, 1785, William Herschel discovered a trio of nebulae along the Pegasus-Pisces border, which he recorded as II 439, II 440, and III 435. John Louis Emil Dreyer listed these three objects in his New General General Catalogue of Nebulae and Clusters of Stars (published in 1888) as NGC 7619, NGC 7626 and NGC 7623.
When seeing a particular target or target area, do the observations of current and/or historical astronomers ricochet in your mind and what effect does this astronomical knowledge have on what you see or the way you think while observing?
TF: Indeed. Since moving to Arizona in 2012, I’ve made an effort to view all of the objects in the NGC that rise above my horizon here. This catalogue is the ultimate list of visually discovered objects as all but one, (NGC 1432) were discovered visually, although 22 objects were discovered with the aid of a spectroscope.
The NGC contains 7,840 entries. However, after removing duplicates and non-existent objects, the actual number of discrete objects in the NGC is 7,052. 6,802 are reasonably accessible from my observatory.
Researching the errors, duplications and lost objects in the catalogue encouraged me to become familiar with the great visual astronomers of the past; the Herschels, Marth, Swift, Stephan, d’Arrest, Dunlop, Leavenworth, Temple and dozens more.
Reaching to the faintest objects, you come to realize that you are seeing objects that very few humans have ever seen with their own eyes. At the moment you are looking at that object, you become the last in a chain of visual observers that stretches back to the discoverer. Isn’t it amazing that you and Sir William Herschel (or whomever) share a visceral experience separated by centuries yet connected in such a very real way? For the very faintest, most obscure objects, the population of observers that have shared that view is rather small. You become part of a unique and privileged group — and for that instant your eye is collecting photons, you and the discoverer are the bookends of that list. If you allow yourself to see it that way, you can’t avoid an almost spiritual awe.
I spent a couple of years concentrating on just Herschel’s discoveries and I have to confess to “conversing” with Sir William on many a solitary observing session, commenting on his objects almost as if he were standing behind me. (That won’t concern me unless he starts to respond).
JS: During seeing, do astrophysical questions come into your mind? Like distance and luminosity of the physical object under study, or category of object (i.e., in the case of a galaxy is it elliptical, spiral, lenticular, barred spiral)? Are some objects optical doubles, or are you looking at things that are physically connected?
TF: Yes, to a minor degree, just describing objects requires a certain amount of that sort of consideration. I like to categorize galaxies before looking to see its established classification. It is sometimes easy to recognize a spiral and sometimes difficult. I always try to consider whether or not any spiral structure is discernible. I’ll often make that determination and then check the DSS image to see if it’s really there.
Having done more than twenty Astronomical League observing programs that require comment on certain characteristics or classification of certain types of objects, I’ve acquired habits such as always judging the concentration of globulars, the classification of open clusters, the position angle of galaxies, etc.
I run the League’s Planetary Nebula Observing Program and I ask observers to report on a number of aspects, such as the visibility of the central star, colour, filter response and how magnification affects visibility. I routinely consider those same factors myself when viewing planetary nebulae.
JS: Do you use averted vision automatically?
TF: Yes. It is a conditioned response that I do not consciously think about usually. However, when objects are quite faint, one does start to consider it. I use a categorization (gleaned from another of those Astronomical League programs) that assigns values to how averted vision is employed. AV1 is the circumstance where the object eventually becomes visible with direct vision. AV2 means the object is held steady with averted vision, where AV3 and AV4 are objects that are perceived more or less than half the time. That AV4 category is akin to the concept of averted imagination where the object is little more than suspected.
JS: What’s the difference between seeing and detecting an object?
TF: I think I touched on this above. Seeing an object is unambiguous of course. It is reliably there, held steady, and perhaps even visible with direct vision.
Detecting is more problematic. First it requires a great deal of self-awareness and critical thinking to separate what you actually see from what you expect to see.
You can recognize the effect of preconceptions in the descriptions of certain objects over time that clearly reflect the prevailing view of the time period. For instance, when the prevailing wisdom held that all nebulae were just unresolved clusters of stars you can find observers that reported detecting stars where there aren’t any. Look at how many past observers were able to “confirm” Lowell’s canals on Mars.
It is particularly difficult with objects that are at the limit of your scope’s resolution. When you know an object is actually there, you can imagine you see it without really knowing for sure whether its faint light actually tips the scales or if it’s just imagined.
JS: How often do you sketch while at the eyepiece, and does sketching help to memorize patterns in the Universe?
TF: I seldom sketch. As a beginner, I did a lot more of it, but in the past two decades, maybe just a handful of times. There is an advantage to sketching as it forces the observer to look for details and consider things like brightness gradients and structure. I find describing things in detailed notes is just as effective. Although with much of the tiny faint nothings I seek these days, there is very little to describe.
JS: Would you use a 20mm Plössl with a 50-degree field of view when looking at deep-sky objects, or do you think that super-wide eyepieces have rendered Plössl eyepieces obsolete?
TF: Would I? Sure. Do I? Not so much. I use Plössls (and similar) eyepieces in my smaller scopes all the time, but in my big Dobs (both are f/4.5 and employ paracorrs) I use mostly two-inch wide field oculars as a matter of habit. I have a large collection of TeleVue Naglers, Panoptics and Ethos eyepieces. I use Tele Vue Radians in my four-inch Tak. It’s just brand loyalty, I suspect. There are many choices out there, and one seldom encounters “bad” modern eyepieces.
Very recently, I acquired a white phosphor night vision monocular that I can adapt to inexpensive super Plössls that are especially threaded for the purpose. The addition of this enhancement may just fundamentally alter the way I observe. With the addition of an Hydrogen-alpha filter, the effect on emission nebula is nothing less than spectacular. It might stretch the definition of visual observing, but it’s just too remarkable to avoid.
JS: Do you make connections with sound while seeing? Once, when I was looking the constellation of Lyra, I heard the distant sound of howling coyotes in the surrounding forest; during another session, suddenly, an asylum of loons landed in the Lagoon Nebula; seeing the Pleiades from incurably light-polluted Toronto this past September while listening to Earth, Wind & Fire’s 1979 hit “September” felt beautifully weird; viewing the Double Cluster in Perseus while listening to Dimitri Shostakovich’s 11th symphony somehow allegorized the two groupings of stars as two cities competing with one another.
Have you listened to William Herschel’s musical compositions while observing?
Do natural ambient sounds intensify your visual experience?
TF: My observatory is called the Desert Coyote Observatory for good reason. I didn’t name it – I purchased my property with the observatory already there and that’s the name the original owner gave it, but I kept it. Coyotes frequently serenade me during observing sessions. The occasional hooting owl is another pleasant night time visitor.
When viewing alone in my observatory, I always listen to music. I enjoy listening to classical music most of the time, but there is an oldies station here that comes in pretty strong and sometimes that is my choice.
And yes, I have listened to William Herschel’s music while observing. I confess he’s not a favourite, but the novelty of it all is irresistible.
JS: What’s the most unusual or funniest thing that’s happened to you when observing?
TF: It’s difficult to do this question justice since humour is such a subjective thing, and what I and my friends found hilarious in the moment would be hard to convey to those that weren’t there.
I suppose one circumstance that falls into the unusual heading was a touching moment at an outreach event. When I lived in Virginia, I used to coordinate a public observing session called Skywatch. One month, a young man called me to ask my collaboration in a scheme he concocted. He had “purchased” a star — you know from that star registry thing — for his girlfriend. His request was for me to find and show his girlfriend “her” star when they arrived at the event. Then while she was viewing the star, he would drop to a knee and propose marriage.
He gave me the details on the star and I agreed. I was using my 18-inch Dob, and in preparation for their arrival, I think I had actually located the star. Maybe. It was very faint and in a crowded star field, but I had a good idea of where it was.
But then, they were very late to the event and her star had set by the time they arrived. Neither of these kids were at all familiar with the sky and I didn’t have the heart to disappoint them of course. So, I made a show of trying to find the star, picked one of about the same magnitude, and described for her how to identify it. The rest went on as planned and they left with beaming smiles, thunderous applause, and a date at the church.
JS: Have you ever accidentally dropped anything down the telescope tube?
TF: Oh yeah. No one does astronomy for decades without mishaps like that. Mine was an Allen wrench that I was using to adjust the secondary. Luckily, it missed the mirror and no harm was done.
But the most memorable “down the tube” moment was one evening in my observatory when I was about to raise the 30-inch Dob to Polaris to begin alignment. It offered a lot more resistance than it should have — due to the 12-pound cat that had climbed through the rocker box and up one of the truss tubes.