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"

11620 results found.

  1. GRB 250919A: BALROG localization (Fermi Trigger 779934537 / GRB 250919020)
  2. GRB 250916A: Fermi GBM Observation
  3. Fermi GRB 250919A: Global MASTER-Net observations report
  4. GRB 250919A: Fermi GBM Final Real-time Localization
  5. GRB 250916A: KAIT optical observations
  6. GRB 250917B: VLT/HAWK-I near-infrared observations
  7. GRB 250916A: NuSTAR detection of the prompt emission
  8. GRB 250916A: further SAO RAS optical observations
  9. GRB 250912A: SVOM/ECLAIRs refined analysis
  10. GRB 250918A: BALROG localization (Fermi Trigger 779891543 / GRB 250918522)
  11. GRB 250918A: Fermi GBM Final Real-time Localization
  12. GRB 250917B: Swift/UVOT Upper Limits
  13. GRB 250916A: OSIRIS+/GTC redshift z = 2.015
  14. GRB 250916A: Swift-XRT observations
  15. GRB 250916A: MAO/AZT-22 optical observations
  16. GRB 250916A: SAO RAS optical observations
  17. GRB 250916A : GIT optical observations
  18. GRB 250916A: Glowbug gamma-ray detection
  19. GRB250917B: WFST optical observations
  20. GRB 250916A: Swift ToO observations
  21. GRB 250917B: Fermi GBM Observation
  22. Fermi GRB 250917B: Global MASTER-Net observations report
  23. GRB 250916A: GOTO optical counterpart candidate
  24. GRB 250917B: Fermi GBM Final Real-time Localization
  25. GRB 250917A: Fermi GBM Final Real-time Localization
  26. GRB 250916A: AstroSat CZTI detection of a bright long burst
  27. Fermi GRB 250916A: Global MASTER-Net observations report
  28. GRB 250916A: Fermi GBM Final Real-time Localization
  29. GRB 250912A: Swift/BAT-GUANO localization skymap of a possibly short burst
  30. GRB 250912A: SVOM/COLIBRÍ (FM-GFT) optical observations
  31. GRB 250912A: Swift-XRT observations
  32. GRB250912A: VLT/HAWK-I follow-up observations
  33. GRB 250912A: Fermi GBM Observation
  34. GRB 250912A: SVOM/GRM analysis suggests a possible short GRB with extended emission
  35. GRB 250912A: LCO optical upper limit
  36. Fermi GRB 250912A: Global MASTER-Net observations report
  37. GRB 250912A: SVOM detection of a burst
  38. GRB 250912A: Fermi GBM Final Real-time Localization
  39. EP250911a: Upper limit from Fermi-GBM Observations
  40. GRB 250910B: SVOM/GRM observation
  41. GRB 250910C: Fermi GBM Final Localization Correction
  42. Fermi GRB 250910B: Global MASTER-Net observations report
  43. GRB 250910B: BALROG localization (Fermi Trigger 779223130 / GRB 250910786)
  44. GRB 250910B: Fermi GBM Final Real-time Localization
  45. GRB 250909A: AstroSat CZTI detection
  46. GRB 250702B: Late time Chandra observations
  47. Fermi GRB 250909A: Global MASTER-Net observations report
  48. GRB 250909A: Fermi GBM Final Real-time Localization
  49. Fermi-LAT Gamma-ray Observations of IceCube-250905A
  50. IceCube-250905A - IceCube observation of a high-energy neutrino candidate track-like event
  51. GRB 250905B: Fermi GBM Final Localization
  52. EP250827a and EP250827b: Upper limit from Fermi-GBM Observations
  53. GRB 250902B: CALET Gamma-Ray Burst Monitor detection
  54. GRB 250902A: CALET Gamma-Ray Burst Monitor detection
  55. GRB 250902A: VZLUSAT-2 detection
  56. GRB 250902A: GECAM-B detection
  57. GRB 250902B: AstroSat CZTI detection
  58. GRB 250902B: SVOM/GRM observation
  59. Fermi GRB 250902B: Global MASTER-Net observations report
  60. Fermi-LAT Gamma-ray Observations of IceCube-250831A
  61. GRB 250902A: Fermi GBM Detection
  62. GRB 250902B: Fermi GBM Final Real-time Localization
  63. GRB 250902A: SVOM/GRM observation
  64. GRB 250902A: Fermi GBM Final Real-time Localization
  65. IceCube-250831A - IceCube observation of a high-energy neutrino candidate track-like event
  66. LIGO/Virgo/KAGRA S250725j: Observations with the NSF-DOE Vera C. Rubin Observatory
  67. GRB 250828A: Fermi GBM Final Localization
  68. GRID detection of GRB 250824A
  69. Fermi GRB 250827A: Global MASTER-Net observations report
  70. GRB 250826A: SVOM/GRM observation
  71. GRB 250827A: Fermi GBM Final Real-time Localization
  72. Fermi GRB 250826A: Global MASTER-Net observations report
  73. Fermi trigger No 777883624: Global MASTER-Net observations report
  74. Fermi Gamma-ray Burst Monitor trigger 777883624/250826283 is not a GRB
  75. GRB 250826A: Fermi GBM Final Real-time Localization
  76. Fermi GRB 250824B: Global MASTER-Net observations report
  77. GRB 250821B: AstroSat CZTI detection
  78. GRB 250821B: Insight-HXMT detection
  79. GRB 250824B: Fermi GBM Final Real-time Localization
  80. GRB 250823A: COLIBRÍ optical observations
  81. GRB 250823A: SVOM/VT optical observation
  82. GRB 250824A: Fermi GBM Final Real-time Localization
  83. GRB 250823A: NOT optical observations
  84. GRB 250823A: Fermi GBM Observation
  85. GRB 250823A: BOOTES6/DPRT early optical detection
  86. GRB 250823A: Liverpool Telescope optical detection
  87. GRB 250823A: Fermi GBM Final Real-time Localization
  88. Konus-Wind detection of GRB 250821B
  89. IPN triangulation of GRB 250821B (long/bright)
  90. GRB 250821B: SVOM/GRM observation
  91. Fermi GRB 250821B: Global MASTER-Net observations report
  92. GRB 250821C: Fermi GBM Final Real-time Localization
  93. GRB 250821B: Fermi GBM Detection
  94. GRB 250821B: BALROG localization (Fermi Trigger / GRB 250821672)
  95. GRB 250821B: Fermi GBM Final Localization of a Bright Burst
  96. GRB 250814A: CMO SAI and SAO RAS izJ observations.
  97. IPN triangulation of GRB 250816A (short)
  98. LIGO/Virgo/KAGRA S250818k: Upper limits from Fermi-GBM Observations
  99. GRB 250818A: AstroSat CZTI detection
  100. Fermi Gamma-ray Burst Monitor trigger 777342746/250820022 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