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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28124 results found.

  1. GRB 260430B: AstroSat CZTI detection of a long burst
  2. GRB 260502A: SVOM/GRM observation of a short GRB
  3. GRB 260503A: SVOM/GRM observation of a GRB
  4. Konus-Wind detection of GRB 260411C
  5. GRB 260504B: REM optical/NIR observations
  6. GRB 260504B: LCO z-band upper limit
  7. SVOM GRB 260504B: MASTER-OAFA optical observations
  8. GRB 260504B: SVOM detection of a short burst
  9. Fermi GRB 260504A: Global MASTER-Net observations report
  10. SVOM/GRM observation of a bright burst from SGR 1E1841-045
  11. GRB 260429B / EP260429a: EP-FXT follow-up observation
  12. EP260502a: Einstein Probe detection of an X-ray transient
  13. GRB 260429A: SVOM/GRM observation of a short burst
  14. SN 2026kid: Optical follow-up with small-aperture telescopes in Spain and China
  15. EP260429a: Global MASTER-Net observations report
  16. EP260430a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  17. GRB 260424B: AstroSat CZTI detection
  18. GRB 260429B / EP260429a: COLIBRÍ optical upper limit
  19. EP260429a: LCO optical upper limits
  20. EP260430a: LCO optical upper limits
  21. GRB 260430A / EP260430a: COLIBRÍ optical upper limit
  22. GRB 260429A: Fermi GBM Detection
  23. Fermi GRB 260429A: Global MASTER-Net observations report
  24. EP260430a: Global MASTER-Net observations report
  25. EP260430a: Einstein Probe detection of an X-ray transient
  26. EP260429a: EP-WXT detection of a fast X-ray transient
  27. GRB 260428A: SVOM/GRM observation of a possible short burst with extended emission
  28. IceCube-260425A: Upper limits from a search for additional neutrino events in IceCube
  29. Fermi GRB 260428A: Global MASTER-Net observations report
  30. EP260416a: Mondy and Terskol optical upper limits
  31. GRB 260424B: Glowbug gamma-ray detection of a short burst
  32. GRB 260424B: COLIBRÍ optical upper limit
  33. Fermi-LAT Gamma-ray Observations of IceCube-260425A
  34. GRB 260305A: likely detection by Fermi-LAT and the LAT gamma-ray position
  35. IceCube Alert 260425A: Global MASTER-Net observations report
  36. Fermi trigger No 798737427: Global MASTER-Net observations report
  37. GRB 260401A: cubesat Avion detection
  38. EP260321a: Upper limits from ATCA radio observations
  39. GRB 260421B: Kilonova-Catcher optical afterglow detection
  40. The EP-WXT trigger 01709258652: Mondy optical observations
  41. EP260416a: Mondy optical observations
  42. GRB 260421B: 3.6m DOT optical observation
  43. EP260416a: ZTSh R band observations
  44. IceCube-Cascade 260418A: Upper limits from a search for additional neutrino events in IceCube
  45. GRB 260421B: SVOM/GRM observation
  46. GRB260421B: J band upper limit by SYSU 80cm infrared telescope
  47. GRB 260421B: EP-FXT follow-up observation
  48. GOTO26djh/AT2026jpw: ATCA radio detection
  49. GRB 260421B: J-band upper limit with WINTER
  50. GRB 260421B: LCO optical counterpart detection
  51. GRB 260421B: Fermi GBM Observation
  52. GOTO26djh/AT2026jpw: radio detection at 15GHz
  53. GRB 260421B: SVOM/VT optical observations
  54. EP260416a: J band upper limit by SYSU 80cm infrared telescope
  55. GRB 260310A: Late-time Chandra X-ray Detection
  56. EP260416a: 1.3m DFOT optical observation
  57. Fermi GRB 260421C: Global MASTER-Net observations report
  58. GRB 260421B: VLT/X-shooter spectroscopic redshift z = 2.115
  59. Fermi GRB 260421B: Global MASTER-Net observations report
  60. GRB 260421B: LCO optical afterglow confirmation
  61. GRB 260421B: SVOM/COLIBRÍ (FM-GFT) optical detection of a candidate counterpart
  62. GRB 260421B: TRT optical counterpart detection
  63. GRB 260421B: SVOM detection of a long burst
  64. GRB 260421B: BALROG localization (Fermi Trigger 798437606 / GRB 260421176)
  65. Fermi GRB 260421A: Global MASTER-Net observations report
  66. EP260321a: VLA radio follow-up
  67. GRB 260412A: LCOGT Optical Upper Limits
  68. EP260416a: Optical follow-up observations with Kinder
  69. GOTO26djh/AT2026jpw: CrAO and Mondy optical observations of the transient
  70. GRB 260417A: SVOM/GRM observation
  71. EP260321A/AT2026gzf: Optical observation from 1.3m DFOT
  72. Fermi trigger No 798275385: Global MASTER-Net observations report
  73. EP260417a: GROWTH-India Telescope optical upper limit
  74. Fermi GRB 260417B: Global MASTER-Net observations report
  75. EP260417b: GROWTH-India Telescope optical upper limit
  76. EP260416a: Ondrejov D50 optical detection
  77. EP260417a: Global MASTER-Net observations report
  78. EP260417a/GRB 260417A: refined analysis of the EP-WXT and follow-up EP-FXT observations
  79. EP260416a: GMG Optical Observation
  80. Fermi GRB 260417A: Global MASTER-Net observations report
  81. EP260416a: LCO observations confirm end of flaring phase
  82. EP260324a / AT2026hir: Further multiband optical follow-up with the PKU 60cm Telescope
  83. EP260417a: TRT optical counterpart detection
  84. EP260417a: Einstein Probe detection of an X-ray transient
  85. EP260416a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  86. EP260417b: Einstein Probe detection of a fast X-ray transient
  87. EP260416a: KAIT optical upper limit
  88. EP260416a: COLIBRÍ confirmation of the optical rebrightening
  89. EP260416a: WFST optical observations and rebrightening
  90. GOTO26djh/AT2026jpw: ZTSh R,I bands observations of the transient
  91. GOTO26djh/AT2026jpw: SVOM/VT optical observation
  92. GRB 260415B: Glowbug gamma-ray detection
  93. GRB 260411B: Glowbug gamma-ray detection
  94. EP260416a: COLIBRÍ optical counterpart candidate
  95. COLIBRI optical observations of the transient GOTO26djh/AT2026jpw
  96. EP260416a: Global MASTER-Net observations report
  97. EP260416a: Einstein Probe detection of an X-ray transient
  98. GOTO26djh/AT2026jpw : MASTER OT observation
  99. GOTO26djh/AT2026jpw transient: SAO RAS optical observations
  100. NOT r-band observations of the transient GOTO26djh/AT2026jpw

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