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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

31727 results found.

  1. GRB 240825A: Skynet Optical Afterglow observations
  2. GRB 240825A: Nanshan/HMT optical afterglow observations
  3. GRB 240824A: Swift-BAT refined analysis
  4. GRB 240824A: SVOM/C-GFT optical upper limit
  5. GRB 240824B: Swift-XRT afterglow detection
  6. LIGO/Virgo/KAGRA S240825ar: Identification of a GW compact binary merger candidate
  7. GRB 240824B: Swift/BAT arcminute localization of a burst
  8. GRB 240824B: Swift ToO observations
  9. Fermi GRB 240824C: Global MASTER-Net observations report
  10. GRB 240824A: Swift/UVOT Upper Limits
  11. GRB 240821A: Swift/UVOT observations of the XRT sources.
  12. GRB 240824B: MAXI/GSC detection
  13. GRB 240824A: Retraction of GCN 37255
  14. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  15. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  16. GRB 240824A: KAIT optical upper limit
  17. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  18. GRB 240821A: Colibri Optical Upper Limit
  19. EP240820a: PRIME J-band Observations
  20. GRB 240821A: Swift-XRT observations
  21. GRB 240821A: REM optical/NIR upper limits
  22. GRB 240821A: LCO optical observations
  23. GRB 240821A: JinShan optical upper limits
  24. GRB 240809A: Mondy and AbAO Optical Observations
  25. GRB 240821A: SVOM/VT follow-up and optical upper limit
  26. GRB 240821A: GMG Optical Upper Limit
  27. Fermi GRB 240821A: Global MASTER-Net observations report
  28. GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
  29. GRB 240821A: Fermi GBM Observation
  30. GRB 240821A: Swift ToO observations
  31. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  32. GRB240821A: EIRSAT-1 GMOD Detection
  33. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  34. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  35. Fermi GRB 240821B: Global MASTER-Net observations report
  36. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  37. GRB 240821A: SVOM/GRM observation
  38. GRB 240821A: SVOM/GRM observation
  39. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  40. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  41. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  42. GRB 240819A: Swift-XRT observations
  43. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  44. EP240820a: TRT optical upper limit
  45. GRB 240819A: KAIT optical upper limit
  46. EP240816a: PRIME upper limits
  47. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  48. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  49. GRB 240819A: Swift ToO observations
  50. GRB 240814A: SVOM/GRM observation
  51. EP240816b: Liverpool Telescope optical follow-up observations
  52. GRB 240814C: SVOM/GRM observation
  53. IceCube-240721A: AT2023qqp and AT2024pge likely unrelated
  54. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  55. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  56. EP240816b: KAIT optical upper limit
  57. GRB 240814B: GRBAlpha detection
  58. EP EP240816b: Global MASTER-Net observations report
  59. EP240816b: TRT optical upper limit
  60. Fermi GRB 240814A: Global MASTER-Net observations report
  61. Fermi GRB 240814C: Global MASTER-Net observations report
  62. Fermi GRB 240814B: Global MASTER-Net observations report
  63. GRB 240812B: SVOM/GRM observation
  64. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  65. LIGO/Virgo/KAGRA S240813d: Updated Sky localization
  66. Konus-Wind detection of GRB 240811A
  67. Konus-Wind detection of GRB 240810A
  68. LIGO/Virgo/KAGRA S240813d: Identification of a GW compact binary merger candidate
  69. LIGO/Virgo/KAGRA S240813c: Updated Sky localization
  70. LIGO/Virgo/KAGRA S240813c: Identification of a GW compact binary merger candidate
  71. GRB 240809A: Correction to the VLA source position in GCN 37158
  72. GRB 240810A: SVOM/GRM observation
  73. GRB 240809A: ATA radio non-detection
  74. GRB 240809A : RAPAS follow-up observations
  75. GRB 240809A: VLA detection
  76. GRB 240809A: ALMA detection
  77. IPN triangulation of GRB 240810A (short)
  78. GRB 240811A: Swift-BAT refined analysis
  79. GRB 240809A: Swift-BAT refined analysis
  80. EP240807a: PRIME H-band upper limits
  81. IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube
  82. GRB 240811A: Bassano Bresciano Observatory upper limit
  83. GRB 240811A: Swift/UVOT Upper Limits
  84. EP240801a: Assy-Turgen optical observations
  85. Fermi GRB 240810A: Global MASTER-Net observations report
  86. GRB 240811A: LCOGT Optical Upper Limit
  87. GRB 240811A: Upper limits with Mephisto
  88. Konus-Wind detection of GRB 240809A
  89. Swift GRB 240811A: Global MASTER-Net observations report
  90. GRB240809A: Liverpool Telescope optical follow-up observations
  91. GRB 240809A: REM detection of the optical afterglow
  92. GRB 240809A: Bassano Bresciano Observatory optical observations
  93. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  94. GRB 240809A: Conclusive redshift from VLT
  95. Fermi-LAT gamma-ray observations of IceCube-240808A
  96. GRB 240809A: KAIT optical observations
  97. GRB 240808A: AstroSat CZTI detection
  98. GRB 240809A: GIT afterglow observations
  99. GRB 240809A: Swift/UVOT Detection
  100. GRB 240809A: Tentative redshift from NOT

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