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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.

Advanced Search Examples (click to copy):

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

26519 results found.

  1. ZTF26aaglqak/AT2026dbl: COLIBRÍ Optical Observations
  2. EP260221a: GOTO optical upper limit
  3. EP260221a: COLIBRÍ optical upper limit
  4. SVOM alert sb26021801: LCO optical upper limit
  5. EP260221a: Einstein Probe detection of an X-ray transient
  6. The EP-WXT trigger 01709258519 is likely caused by Mrk 421
  7. GRB 260219A: AstroSat CZTI detection
  8. GRB 260219A: GECAM-B observation of a long burst
  9. SVOM alert sb26021801: LAST optical upper limit
  10. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  11. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  12. sb26021801: SVOM detection of a long faint X-ray transient
  13. EP260214b: 1.3m DFOT optical upper limit
  14. Konus-Wind detection of GRB 260212A
  15. IPN triangulation of GRB 260212A
  16. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  17. GRB 260213A: GECAM-B observation of a short burst
  18. EP260214b: Liverpool Telescope optical observations
  19. EP260214b: Optical upper limit with Kinder observations
  20. EP260214a: Optical upper limits with Kinder observations
  21. EP260214b: EP-FXT follow-up observation
  22. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  23. EP260214b: DDOTI Optical Detection
  24. EP260214b: GROWTH-India Telescope optical upper limit
  25. EP260214b: SVOM/VT optical observation
  26. EP260214a: COLIBRÍ optical upper limits
  27. EP260214b: OHP/T120 optical observations
  28. EP260214a: refined analysis of the EP-FXT observation
  29. EP260214b: LCO optical counterpart detection
  30. GRB 260211A: SVOM/VT optical counterpart
  31. EP260214b: COLIBRÍ optical observations
  32. EP260214a: SVOM/VT optical upper limits
  33. EP260214b: NOT optical counterpart detection
  34. EP260214b: Einstein Probe detection of a fast X-ray transient
  35. EP260214a: Einstein Probe detection of an X-ray transient
  36. GRB 260212A: AstroSat CZTI detection
  37. GRB 260212A: Fermi GBM Observation
  38. EP260213a: COLIBRÍ optical upper limits
  39. GRB 260212A: GECAM-B observation
  40. EP260213a: Optical upper limits with Kinder observations
  41. EP260213a: SVOM/VT optical upper limit
  42. EP260213a: NUTTelA-TAO Early Optical Limits
  43. EP260213a: SVOM/C-GFT upper limit
  44. EP260213a: refined analysis of the EP-FXT observation
  45. EP260213a: Einstein Probe detection of a fast X-ray transient
  46. GRB 260212A: SVOM/GRM observation of a long burst
  47. GRB 260211A - SVOM/ECLAIRs refined analysis
  48. GRB 260204A: SVOM/ECLAIRs refined analysis
  49. GRB 260211A: EP-FXT follow-up observation
  50. GRB 260211A: SVOM/VT optical observation
  51. GRB 260212A: Glowbug gamma-ray detection
  52. GRB 260211A: GOTO optical upper limit
  53. GRB 260211A: LAST optical upper limit
  54. GRB 260210A: SVOM/GRM observation
  55. Fermi GBM Sub-Threshold Detection of GRB 260211A
  56. Konus-Wind detection of GRB 260207B
  57. GRB 260128B: SVOM/ECLAIRs refined analysis
  58. GRID detection of GRB 260207B
  59. GRB 260211A: LCO optical upper limits
  60. GRB260131A/B: 3.6m DOT Optical Observations
  61. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  62. GRB 260211A: SVOM detection of a burst
  63. Swift Operations Update + Community Forum (Friday, February 13 @ 10:00 AM EST)
  64. Konus-Wind detection of GRB 260209B
  65. GRB 260208A: Swift UVOT detection
  66. Konus-Wind detection of GRB 260127B
  67. EP260209a: COLIBRÍ optical upper limit
  68. EP260210a: refined analysis of the EP-FXT observation
  69. GRB 260208A: LCO detection of the optical counterpart
  70. EP260209a: Einstein Probe detection of a fast X-ray transient
  71. EP260210a: Optical upper limits with Kinder observations
  72. IPN triangulation of GRB 260207B (short/hard with EE)
  73. GRB 260210A: Glowbug gamma-ray detection
  74. EP260210a: SVOM/VT optical upper limit
  75. GRB 260210A: AstroSat CZTI detection
  76. GRB 260208C: AstroSat CZTI detection
  77. EP260210a: COLIBRÍ optical upper limit
  78. EP260210a: SVOM/C-GFT upper limit
  79. GRB 260208B: refined analysis of the EP-FXT observation
  80. EP260210a: Einstein Probe detection of an X-ray transient
  81. GRB 260207B: AstroSat CZTI detection
  82. GRB 260208C: SVOM/GRM observation
  83. GRB 260204A: Swift-XRT afterglow detection
  84. GRB 260208B: AstroSat CZTI detection of a bright long burst
  85. GRB260208A: Liverpool Telescope optical follow-up observations
  86. GRB 260208A: Glowbug gamma-ray detection
  87. GRB 260208A: NuSTAR detection of prompt emission
  88. GRB 260208A: Fermi GBM Observation
  89. GRB 260208B: Swift-XRT observations
  90. GRB 260131A/B: continued Mondy optical observations
  91. GRB 260204A: Swift/UVOT Upper Limits
  92. GRB 260208B: COLIBRÍ optical observations
  93. GRB 260208A: 1.3m DFOT optical detection
  94. GRB 260208A: COLIBRÍ optical observations
  95. GRB 260208B: EP-FXT observation
  96. GRB 260208A: NOT spectroscopic redshift z = 2.36
  97. GRB 260208B: SVOM/VT optical candidate
  98. GRB 260208A: GECAM-B observation of a bright burst
  99. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  100. GRB 260208A: SVOM/VT optical observation

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