Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

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"

36349 results found.

  1. GRB 240825A: REM detection of the optical/NIR afterglow
  2. GRB 240825A: Swift-XRT refined Analysis
  3. GRB 240825A: VLT/X-shooter redshift
  4. GRB 240825A: SVOM/C-GFT optical observations
  5. GRB 240825A: Montarrenti Observatory optical observations
  6. GRB 240825A: Enhanced Swift-XRT position
  7. GRB 240825A: MASTER optical counterpart observation
  8. GRB 240825A: Fermi-LAT detection
  9. GRB 240825A: LCO optical observations
  10. GRB 240824B: KAIT optical upper limit
  11. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  12. GRB 240824B: Fermi GBM Observation
  13. Fermi GRB 240825A: Global MASTER-Net observations report
  14. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  15. GRB 240824B: NOT optical upper limit
  16. GRB 240825A: GMG Optical Observation
  17. Swift GRB 240825A: Global MASTER-Net observations report
  18. GRB 240825A: 1.6m Mephisto multi-band detection
  19. GRB 240825A: AKO Optical Afterglow Detection
  20. GRB 240825A: Skynet Optical Afterglow observations
  21. GRB 240825A: Nanshan/HMT optical afterglow observations
  22. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  23. GRB 240825A: Fermi GBM Final Real-time Localization
  24. GRB 240824A: Swift-BAT refined analysis
  25. GRB 240824A: SVOM/C-GFT optical upper limit
  26. GRB 240824B: Swift-XRT afterglow detection
  27. GRB 240824A: Swift-XRT observations
  28. GRB 240824B: Swift/BAT arcminute localization of a burst
  29. GRB 240824B: Swift ToO observations
  30. Fermi GRB 240824C: Global MASTER-Net observations report
  31. GRB 240824C: Fermi GBM Final Localization
  32. GRB 240824A: Swift/UVOT Upper Limits
  33. GRB 240821A: Swift/UVOT observations of the XRT sources.
  34. GRB 240824B: MAXI/GSC detection
  35. GRB 240824B: Fermi GBM Final Real-time Localization
  36. GRB 240824A: Retraction of GCN 37255
  37. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  38. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  39. GRB 240824A: KAIT optical upper limit
  40. GRB 240824A: Skynet Optical Afterglow Discovery
  41. GRB 240824A: Swift detection of a burst
  42. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  43. GRB 240821A: Colibri Optical Upper Limit
  44. GRB 240821A: Swift-XRT observations
  45. GRB 240822A: AstroSat CZTI detection of a short burst
  46. GRB 240821A: REM optical/NIR upper limits
  47. GRB 240821A: LCO optical observations
  48. GRB 240821A: JinShan optical upper limits
  49. GRB 240809A: Mondy and AbAO Optical Observations
  50. GRB 240821A: SVOM/VT follow-up and optical upper limit
  51. GRB 240821A: GMG Optical Upper Limit
  52. Fermi GRB 240821A: Global MASTER-Net observations report
  53. GRB 240821A: Fermi GBM Observation
  54. GRB 240821A: Swift ToO observations
  55. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  56. GRB240821A: EIRSAT-1 GMOD Detection
  57. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  58. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  59. Fermi GRB 240821B: Global MASTER-Net observations report
  60. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  61. GRB 240821A: SVOM/GRM observation
  62. GRB 240821A: SVOM/GRM observation
  63. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  64. GRB 240821B: Fermi GBM Final Localization
  65. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  66. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  67. GRB 240821A: Fermi GBM Final Real-time Localization
  68. GRB 240819A: Swift-XRT observations
  69. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  70. GRB 240820B: SVOM/GRM observation
  71. GRB 240819A: KAIT optical upper limit
  72. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  73. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  74. GRB 240819A: X-ray follow-up observation with EP-FXT
  75. Fermi Gamma-ray Burst Monitor trigger 745811685 / 240820080 is not a GRB
  76. GRB 240820A: Fermi GBM Final Real-time Localization
  77. GRB 240819A: Swift ToO observations
  78. GRB 240814A: SVOM/GRM observation
  79. GRB 240814C: SVOM/GRM observation
  80. GRB 240815A: SVOM/GRM observation
  81. GRB 240817A: Fermi GBM Final Real-time Localization
  82. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  83. IBAS Alert n.10856: not a GRB
  84. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  85. EP240816b: KAIT optical upper limit
  86. GRB 240814B: GRBAlpha detection
  87. Fermi GRB 240814A: Global MASTER-Net observations report
  88. Fermi GRB 240814C: Global MASTER-Net observations report
  89. GRB 240814C: Fermi GBM Final Real-time Localization
  90. Fermi GRB 240814B: Global MASTER-Net observations report
  91. GRB 240812B: SVOM/GRM observation
  92. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  93. GRB 240814B: Fermi GBM Final Real-time Localization
  94. GRB 240814A: Fermi GBM Final Real-time Localization
  95. Konus-Wind detection of GRB 240811A
  96. Konus-Wind detection of GRB 240810A
  97. Fermi Gamma-ray Burst Monitor trigger 745220784/240813240 is not a GRB
  98. GRB 240809A: Correction to the VLA source position in GCN 37158
  99. GRB 240810A: SVOM/GRM observation
  100. Fermi Gamma-ray Burst Monitor trigger 240812940/745194848 is not a GRB

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov