How soon could extrasolar planets have been discovered? Options

[Mongo]

Extrasolar pulsar planets were first discovered in 1992, and the first planets around main-sequence stars in 1995. However, it seems clear that main-sequence exoplanets could have been found much earlier, except for the fact that nobody actually looked for them in a way that would have succeeded.

The standard assumption was that all, or almost all, planetary systems followed the architecture of our own system -- a few terrestrial planets at distances ranging from a few tenths of an AU to a few AUs, with larger gas- and ice-giants further out. This would result in systems that are basically impossible to detect with the technology of the time, except perhaps for long-term (years to decades) astrometric studies of nearby dwarf stars. It was known that planetary transits would be easily detectable, but they were thought to be so unlikely due to the geometry, as well as being infrequent in the few existing transiting systems, that they were not worth the resources spent searching for them. Radial velocity searches were considered to be out of the question, with stellar RV shifts ranging up to a few m/s at best, well below the best sensitivity of the spectroscopes of the time.

In fact, "Hot Jupiters" are common, with RV swings measured in the tens or hundreds of m/s, and transiting planets are so common and easy to spot that many current search programs use telescopes no larger than typical amateur telescopes. Today's detectors are better, of course, but that could be compensated for with a slightly larger telescope.

I assume that a planet search program consisting of an all-sky transit search with one or more 30cm-class telescopes would produce several dozen candidates (with at least three observed transits each) orbiting fairly visually bright stars within a few months. Each of those would be examined spectroscopically, and each would be soon found to have RV swings of 50-200 m/s or more. With the existing spectroscopic classification of the primary stars, this would result in fairly accurate masses and radii for each of these planets, as well as expected daytime temperatures. It would be easy to calculate the frequency of "Hot Jupiters" around main-sequence stars (around 1%), and the "inflated Jupiter" effect should be apparent in the data.

So assuming that some astronomer manages to obtain funding and telescope time to conduct such a program, when was the astronomical photometer and spectroscope technology advanced enough for this to have succeeded? The 1960s? 1970s? Surely by the 1980s, at the latest, which seems very late to me.

[JCG]

Thank you for the welcome, Mongo. The frustration with progress from both professional and layman's perspective is the inability to do everything at once. Ah! If we could! For the professional the last 50 years of astronomy is like being at Disneyland (dates me!) with only enough money for a ticket or two and only one short visit per year. What rides to chose and in what order for the next decade or so? Very frustrating but calls for calm planning; sometimes projects just have to wait.
The advent of the inexpensive professional quality CCD and large high-quality telescope (~< 1 m) has allowed many amateur astronomers to become productive members of the space exploration community providing high quality results. Something I find amazing and gratifying since these able souls have taken on some of the burden on astronomers decades ago. An anecdote in that regard: I started with visual observations for the AAVSO when I was kid in the late 60s. In the early 70s I worked with an engineer at LPL to make a single channel photometer with Si-photodiodes to make an inexpensive photometer for amateurs who could not afford expensive 1P21 phototube-based systems (even home-built) - I never trusted my visual observations of magnitude. The sensitivity was not very good in those devices, but would be better than an inexperienced eye alone. The project got displaced by graduate studies (priorities!) and I never went back to the project. Now it is a moot point.
Another anecdote from that time period concerning priorities and prevalence of instrumentation to perform state-of-the-art observations: In the mid-70s I was fortunate enough to be able to use Frank Low's Ge (germanium) bolometer (at LPL/UA) for thermal measurements (10 and 20 micron bands) of asteroids. I had access to the world's state-of-the-art detector system, which was state-of-the-art because it was for all practical purposes one of the only such bolometers around. So, I was able to make measurements no one else could, but I also took time away from every other astronomer who wanted to use that system for any other type of observation. Remember this was when quasars were little understood as were any other number of now commonly understood, post-Hubble, IRAS, etc., phenomena - there were lots of "hot topics" to go after besides asteroids. Anyway, every observing program can get preempted. One early morning (I mean about 5 am, just before dawn) in August 1975, Frank (and a colleague) burst onto the observing floor (after having driven 30 miles to the Mt Lemmon Observatory) stating excitedly, "I need the bolometer!" It was his device so what could I say? He ran onto the observing platform and slew the telescope around to Nova Cyg which had just gone off and was still increasing in magnitude. In a few minutes he made enough measurements of the thermal profile to reach quantitative conclusions for (at the time crude) time-phased modeling of the shock and dust cloud expansion still in the expansion stage, "packed his bags" and left. I was more than happy to oblige Frank, not just because it was his instrument, but because I understood the priorities of the moment. Now there are dedicated searches and automatic measurements of energetic events from thermal to gamma rays. Back then such measurements could be done but only by chance circumstances - the Ge just happened to be at a telescope ready to go.
In a very general sense we all understand why it takes so long to move forward in discovery, especially in "search" programs. That does not relieve the frustration. However, this thread does bring to mind that the details of why science lurches forward are filled with human experience, discovery and disappointment, fun and misery, perseverance and ... retirement ... which can avert that frustration with amusement.
So, Mongo, me go eat beans and watch more Mel Brooks!

P.S. Remind me to tell the story of how, in 1976, a Jesuit priest parted the clouds for 30 minutes one night at Kitt Peak allowing two critical (polarimetric) measurements that helped alter our understanding of quasars and NEOs. The bit about the Jesuit priest, the parting of the clouds, the importance of the observations, etc., is true but whether due to chance circumstance or divine intervention makes for amusing discussion. Another beer, please. JCG