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"

23687 results found.

  1. GRB251026B: PRIME H-band upper limit
  2. GRB 251028A: MAXI/GSC detection
  3. SVOM trigger sb25102702/GRB 251027A is not a GRB
  4. GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
  5. GRB 251026B: Swift-XRT observations of GOTO25jgl/AT2025absf
  6. GRB 251025C: Glowbug gamma-ray detection
  7. Konus-Wind detection of GRB 251022A
  8. GRB 251027A: Swift-XRT observations
  9. EP251027.145: COLIBRÍ optical upper limits
  10. GRB 251022A: SVOM/GRM observation
  11. GRB 251027A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  12. GRB 251025B: Kilonova-Catcher optical afterglow detection
  13. Konus-Wind detection of GRB 251016A (short/hard)
  14. GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
  15. GRB 251026B: Tentative GOTO optical counterpart candidate
  16. GRB 251025C: AstroSat CZTI detection
  17. GRB 251025C: CALET Gamma-Ray Burst Monitor detection
  18. GRB 251025B: MAO/AZT-22 optical observations
  19. LIGO/Virgo/KAGRA S251026bn: Identification of a GW compact binary merger candidate
  20. GRB 251026A: Swift-XRT observations
  21. GRB 251025B: J-band detection with WINTER
  22. IceCube-251025A: DDOTI Optical Upper Limit
  23. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  24. GRB 251026A: SVOM detection of a long burst
  25. GRB 251025B: SVOM/VT optical bump
  26. GRB 251025B: SVOM/COLIBRÍ (FM-GFT) strong rebrightening of the optical counterpart
  27. GRB 251023A: SVOM/GRM observation
  28. GRB 251025B: ULL-ASTRO-MASTER optical counterpart detection with IAC80 telescope at Teide Observatory
  29. Konus-Wind detection of GRB 251016B
  30. GRB 251024A: Swift/UVOT Upper Limits
  31. GRB 251025B: Swift-XRT afterglow detection
  32. GRB 251024A: Swift-BAT refined analysis
  33. GRB 251025B: SVOM/VT optical observations with VHF data
  34. GRB 251025B: SVOM/C-GFT optical counterpart detection
  35. GRB 251025B: SVOM detection of a burst
  36. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  37. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  38. GRB 251025A: SVOM/VT VHF optical upper limit
  39. GRB 251025A: SVOM detection of a faint burst
  40. GRB 251023C: Glowbug gamma-ray detection
  41. GRB 251022A: KAIT optical observations
  42. GRB 251024A: Swift detection of a burst
  43. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  44. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  45. GRB 251023B: OHP/T193 optical observations
  46. GRB 251023C: AstroSat CZTI detection
  47. GRB 251022A: Swift-XRT detection of GOTO25iym
  48. GRB 251023C: CALET Gamma-Ray Burst Monitor detection
  49. GRB 251023A: Glowbug gamma-ray detection
  50. GRB 251023B: Glowbug gamma-ray detection
  51. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  52. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  53. IPN triangulation of GRB 251016B
  54. GRB 251023B: CALET Gamma-Ray Burst Monitor detection
  55. EP#01709247298: Swift-XRT counterpart detection
  56. EP251023a: COLIBRÍ optical observations
  57. GRB 251013C: further SAO RAS optical observations
  58. GRB 251022A: COLIBRÍ optical observations
  59. GRB 251022A: DDOTI Optical Detection
  60. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  61. EP251023a: GSP Optical Counterpart Detection
  62. EP/WXT 01709247295: GOTO optical afterglow candidate.
  63. GRB 251022A: GOTO optical counterpart detection
  64. GRB 251022A: Fermi-LAT detection
  65. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  66. EP251021b: BOOTES-7 optical upper limit
  67. GRB 250911A: MAXI/GSC detection
  68. GRB 251016A: SVOM/ECLAIRs refined analysis
  69. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  70. Fermi-LAT gamma-ray observations of IceCube-251018A
  71. GRB 251017A : RAPAS follow-up observations
  72. GRB 251017A: COLIBRÍ optical observations of a late plateau
  73. IceCube-251018A: DDOTI Optical Upper Limit
  74. GRB 251017A: Swift-BAT refined analysis
  75. GRB 251018A: Fermi GBM Observation
  76. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  77. GRB 251018A: Swift-XRT refined Analysis
  78. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  79. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  80. GRB 251017A: COLIBRÍ photometric redshift
  81. GRB 251017A: Swift-XRT refined Analysis
  82. GRB 251018A: TRT optical afterglow detection
  83. GRB 251018A: Swift detection of a burst with an optical counterpart
  84. GRB 251017A: J-band detection with WINTER
  85. GRB 251017A: Glowbug gamma-ray detection
  86. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  87. Swift Trigger 1404295 is not a GRB
  88. GRB 251016A: AstroSat CZTI detection of a short burst
  89. GRB 251017A: COLIBRÍ Early Afterglow Detection
  90. GRB 251016B: AstroSat CZTI detection
  91. GRB 251017A: BOOTES-5/JGT early optical afterglow detection
  92. GRB 251017A: Swift detection of a burst with an optical counterpart
  93. GRB 251016A: CALET Gamma-Ray Burst Monitor detection
  94. GRB 251016B: CALET Gamma-Ray Burst Monitor detection
  95. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart
  96. GRB 251007B: Swift-BAT refined analysis
  97. GRB 251014D: Swift-BAT refined analysis
  98. GRB 251016A: BOOTES-6/DPRT optical upper limit
  99. GRB 251016A: Glowbug gamma-ray detection of a short burst
  100. sb25101602: Swift-XRT counterpart detection

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