The tau-Herculids are an obscure shower produced by the remnants of comet 73P/Schwassmann-Wachmann 3. These meteors are only seen when the Earth passes through one of the filaments produce by this comet during previous returns to perihelion. Mikhail Maslov has posted on the Forum of the International Meteor Organization that just such a chance exists on May 30 near 17:24 Universal Time, when the earth passes close to the debris shed by this comet in 1941. The passage to the core of the filament is not exceptionally close (.00207 AU or 309,672 km) so little to no activity is expected. Any activity should be bright and interesting to witness therefore we encourage observers to view for at least an hour on this night and nights surrounding this date to verify any such activity. The radiant is expected to be located near 211.2 (14:05) +29.7 at the time of maximum activity. This area of the sky is located on the border of Bootes and Canes Venatici, about 7 degrees west of the pair of 4th magnitude stars known as rho and sigma Bootes. Notice that this area of the sky is a bit west of the constellation of Hercules for which this shower is named. The actual radiant location can vary considerably from one display to another depending on the exact circumstances for each encounter. This area of the sky is above the horizon all night long as seen from the northern hemisphere and also well placed for the southern tropics. It should be noted that the true radiant area could be off by several degrees due to several factors, most notably zenith attraction. Therefore do not be too strict with shower association with these meteors. Any slow meteor close to intersecting the radiant area could be a tau-Herculid. With an entry velocity of only 17km/sec, these meteors will appear to be extremely slow compared to most shower meteors.

This timing of 17:24 UT on May 30 is favorable for South and Eastern Africa, the Middle East, and most of Asia. Regardless of your location, we would encourage you to try and see any activity from this source on the nights of May 29-31. If you do observe please post your results to The IMO Forum.

Five years from now on 31 May 2022, this same shower may produce a strong display as the Earth plows though the central regions of the filament created by 73P/Schwassmann-Wachmann 3 during its return in 1995. We are all looking forward to that display!


Location of the tau-Herculid (TAH) on May 30 near midnight local summer time and examples of possible shower members



  • confirming tau herculidszx, one nite prior to peak nite, on morning of june 8th, becuz morning of peak june 9th is supposed to be cloudy, here in NJ. to confirm 3 definite meteorszx, one large at 3am and 2 fainter, afterward – looking more like a radiant @T cygnus, tho hercules is close enough to cygnus to account for this. also, to confirm a brief, but moderately strong flash @T tail of cygnus. this indicateszx a ZHR of 3-4 per hour, close enough to peak nite. nice smaller meteor shower. definitely impressed for a minor shower, tho i cud not travel to get away from lite pollution. overall, still interesting and confirming activity. will try here in NJ tomorow nite, for peak activity as well, and post more updateszx, if possible. have nice map of this now, if anyone wantsxx to help better calculate tha radiant, lemme kno…
    galaxy commander vahj
    of the jade falconszx

    Reply to Andre Smaniotto
  • this is galaxy commander vahjahjikira of the jade falconszx, reporting an update on the presence and activity if the tau herculid meteor shower. under clear skies and moving around moonlite timeszx, on peak nite, here in nj, i can confirm two more small meteorszx, both occurring near the very far tail end of cynus, moving in almost opposite directionszx, and with one movinv rite next to, and alongside of the moon (near jupiter and saturn btw). i am also confirming a single brite flash, directly on the wing of cygnus, on the wing side opposite of the moon (toward cassiopeia / opposite wing from delphi), because it occur almost directly on star of asterism wing, and was very brite and large. this info actually suggests that the peak was last nite (see other post above) because all the meteorszx that did occur on the marked peak of june 9th, were much further to the rear of cygnus. this discrepency could be accounted for by the presence of leap year in 2020, meaning the peak was last nite, june 8th or the following nite of june 10th. i will double check this further tomorow nite, weather permitting, here in nj, but this is an interesting additional piece of information to add to this shower’szx activity, when correctly determining the ACTUAL peak nite, of such an obscure shower in the first place, and given the consideration that 2020 is a leapyear, this will help accurately calculate the exact peak, AND we can also notice how tha radiant center shifted slightly to the rear of cygnus, most probably due to a leap year peak date correction adjustment. i will update further tomorrow if there is more to be deduced here, if the weather permitszx one more de out from the given peak date.

    Reply to Andre Smaniotto
  • this is galaxy commander vahj of the jade falconszx, posting final update on tau herculid activity for final nite of peak activity. my previous post suggested the peak nite shifted, possibly due to leap year. on the nite of the 10th, i am now confirming 7 small meteorszx, all without tailszx, and all in parallel succesion, and all ocurring within 20 minuteszx. this, or the one large one on the 8th seem to indicate either a shifted peak nite, due to leap year, one way or the other. this i cannot fully determine, which way… or possibly just indicate an earlier start due to the leap year, and the natural progression from larger debris of comet, into smaller debris, over time (a total span of three dayszx to fully map), but map is now complete, if anyone wantszx to exchange more info with me. simply lemme kno!!

    Reply to Andre Smaniotto

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