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[2026-09-20] · src Yang, Troja, Monsalves, El Kabir, Shahamat Dehsorkh, Waseem; arXiv:2609.20787 (2026-09-18)
Long gamma-ray bursts are usually attributed to the collapsar channel - a massive star's core collapsing to a black hole, with the accompanying supernova as the signature - but a minority have been seen without one since GRB 060614 in 2006. Yang et al. mined two decades of Swift data for nearby (z <~ 0.35) long GRBs lacking a supernova detection sensitive enough to rule one out, more than doubling the previously known candidate sample through more careful vetting of non-detections. From that enlarged sample they derive the first robust volumetric rate for the population, R = 0.5 +/- 0.2 Gpc-3 yr-1 at luminosities L >~ 1050 erg/s - comparable to the apparent rate of both short GRBs and ordinary supernova-bearing long GRBs. For plausible beaming corrections, that rate lands in the range several compact-binary-merger channels are expected to produce, though the sample's properties are heterogeneous (some in star-forming or dusty hosts, some in quiescent galaxies), which argues against a single progenitor for all of it.
This is the first time the supernova-less long-GRB population has had a quantitative rate rather than a handful of individually strange bursts, and the number that came out - comparable to the short-GRB rate rather than a small fraction of it - is large enough to matter for progenitor bookkeeping: if even part of this population is compact mergers producing collapsar-like jets, it complicates the clean duration-based split between merger and collapse progenitors that short/long GRB classification has rested on. The authors are appropriately cautious that the sample is still small and heterogeneous, so this sets up the question rather than closing it: a larger sample is what would say whether this is the faint tail of known channels or a genuinely separate route to a relativistic explosion.
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[2026-09-20] · src twelve-keys/src/exercises/charleston_comp/exercise.py
Piano gets the whole hour today: three days is the longest real gap of the three instruments right now, alto and trumpet both went in the last two days, and piano is the one that rewards a longer session over a quick one. It opens the comping & time family's third lap with the member the last two sessions haven't touched at all — not another voicing shape, but the pattern underneath every voicing so far: chord on beat 1, then the same chord again on the "and of 2," tied through to the bar's end. Applied to a two-bar ii-V, Am7 to D7, in G major — the plainest key on paper and, after three sessions running on flats, the one with the fewest black keys to find the shapes by feel.
5 minutes: left hand alone, A on beat 1 of bar one, D on beat 1 of bar two, nothing else — total silence for the rest of each bar. Count the whole bar out loud on every repetition: "ONE, two-AND-hold." The point is locating exactly where the second attack goes before the right hand gives you anything to lean on.
Hands together, quarter = 88, six consecutive two-bar cycles with no stop between them. Success criterion: the second RH attack lands audibly ahead of beat 3, not on it, and beat 3 itself is never re-struck — the tie carries it. Between the two chords, C and B should feel like they don't move at all; only the middle finger's note drops from G to F♯. If a pass needs a restrike to hold through beat 3, or the top voice can't stay still, that pass doesn't count toward the six.
Loop the two-bar cycle for eight full loops (sixteen bars) and leave the space between the two attacks genuinely empty — no filling it with extra notes, no rushing to the next chord. The exercise's own point is that the gap is where a soloist breathes; if you can't imagine a melody having room to sit in that silence, the comping is too busy, not too sparse.
Stop the moment the anticipation stops pushing and starts landing flat on the beat — that's the tell that the time feel is degrading, not the fingers. A clean six is the target, not volume; a seventh cycle played metronomically straight rehearses the wrong habit.
[2026-09-20] · src —
hearCount Basie's Kansas City Seven — Dickie's Dream · Tidal · Spotify
Today's exercise names its own source: the intro credits "Count Basie's rhythm section" of the 1940s with making the Charleston pattern jazz piano's default comp, and this 1939 small-group session is that same rhythm section — Basie, Freddie Green, Walter Page, Jo Jones — cut before the decade the exercise is talking about even started. It's the flip side of "Lester Leaps In," already used here on 09-14: same date, same septet, this time built on Lester Young's other contribution to the session. Listen for how little piano there is and how much the two-attack pattern still carries the whole rhythm section — the same economy today's technical target is drilling in G.