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"

32724 results found.

  1. EP260224a: LCO optical upper limits
  2. GRB260225A: SVOM/ECLAIRs refined position
  3. GRB 260225A: EP-FXT follow-up observation
  4. GRB 260225A: SVOM/VT optical observation
  5. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  6. GRB 260223A: Fermi GBM Observation
  7. GRB 260225A: SVOM/VT optical upper limits
  8. EP260126a: VLA 6 GHz detection
  9. EP260223a: Liverpool Telescope upper limits
  10. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  11. EP 260225.148: COLIBRÍ Confirmation of flaring star
  12. EP260223a: Xinglong optical upper limit
  13. GRB 260223A: Glowbug gamma-ray detection
  14. EP260213a: Mephisto optical upper limits
  15. EP260223a: EP-FXT follow-up observation
  16. sb26021801: SVOM/VT optical upper limits
  17. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  18. sb26021801: SVOM/C-GFT upper limit
  19. EP260223a: COLIBRÍ optical upper limits
  20. GRB 260223A: SVOM/VT optical observation
  21. GRB 260223A: SVOM/GRM observation
  22. GRB 260223A: COLIBRÍ further optical observations and a brightening
  23. EP260221a: Optical upper limit with Kinder observations
  24. GRB 260223A: COLIBRÍ optical observations
  25. GRB 260223A: DDOTI Optical Candidate
  26. Fermi GRB 260223A: Global MASTER-Net observations report
  27. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  28. EP260221a: COLIBRÍ optical counterpart candidate
  29. EP260221a: Gemini South z-band upper limit
  30. EP260221a: Global MASTER-Net observations report
  31. EP260221a: EP-FXT follow-up observation
  32. Fermi GRB 260221B: Global MASTER-Net observations report
  33. EP260221a: Xinglong optical upper limit
  34. Fermi GRB 260221A: Global MASTER-Net observations report
  35. EP260221a: GOTO optical upper limit
  36. EP260221a: COLIBRÍ optical upper limit
  37. SVOM alert sb26021801: LCO optical upper limit
  38. GRB 260219A: AstroSat CZTI detection
  39. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  40. GRB 260219A: GECAM-B observation of a long burst
  41. Fermi GRB 260219A: Global MASTER-Net observations report
  42. SVOM alert sb26021801: LAST optical upper limit
  43. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  44. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  45. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  46. EP260214b: Mondy optical observations
  47. EP260214b: 1.3m DFOT optical upper limit
  48. EP260210a: Mondy optical upper limits
  49. Konus-Wind detection of GRB 260212A
  50. GRB 260208A: AbAO and Terskol optical upper limits
  51. GRB 260208A: continued Mondy optical observations
  52. IPN triangulation of GRB 260212A
  53. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  54. GRB 260213A: GECAM-B observation of a short burst
  55. EP260214b: Liverpool Telescope optical observations
  56. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  57. EP260214b: Optical upper limit with Kinder observations
  58. EP260214a: Optical upper limits with Kinder observations
  59. EP260214b: EP-FXT follow-up observation
  60. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  61. EP260214b: DDOTI Optical Detection
  62. EP260214b: GROWTH-India Telescope optical upper limit
  63. EP260214a: VLT near-infrared observation
  64. EP260214b: SVOM/VT optical observation
  65. EP260214a: NOT optical upper limits
  66. EP260214a: COLIBRÍ optical upper limits
  67. EP260214b: OHP/T120 optical observations
  68. EP260214a: refined analysis of the EP-FXT observation
  69. EP260214b: LCO optical counterpart detection
  70. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  71. GRB 260211A: SVOM/VT optical counterpart
  72. EP260214b: COLIBRÍ optical observations
  73. EP260214a: SVOM/VT optical upper limits
  74. EP260214b: NOT optical counterpart detection
  75. EP260214a: Global MASTER-Net observations report
  76. GRB 260212A: AstroSat CZTI detection
  77. GRB 260212A: Fermi GBM Observation
  78. EP260213a: Liverpool Telescope optical upper limits
  79. EP260213a: Global MASTER-Net observations report
  80. EP260213a: COLIBRÍ optical upper limits
  81. GRB 260212A: GECAM-B observation
  82. EP260213a: Optical upper limits with Kinder observations
  83. EP260213a: SVOM/VT optical upper limit
  84. EP260213a: Mondy R-band optical upper limit
  85. EP260213a: NUTTelA-TAO Early Optical Limits
  86. EP260213a: SVOM/C-GFT upper limit
  87. EP260213a: refined analysis of the EP-FXT observation
  88. GRB 260212A: SVOM/GRM observation of a long burst
  89. GRB 260211A - SVOM/ECLAIRs refined analysis
  90. GRB 260204A: SVOM/ECLAIRs refined analysis
  91. GRB 260211A: EP-FXT follow-up observation
  92. GRB 260211A: SVOM/VT optical observation
  93. GRB 260212A: Glowbug gamma-ray detection
  94. GRB 260211A: GOTO optical upper limit
  95. Fermi GRB 260212A: Global MASTER-Net observations report
  96. GRB 260211A: LAST optical upper limit
  97. GRB 260210A: SVOM/GRM observation
  98. Fermi GBM Sub-Threshold Detection of GRB 260211A
  99. Konus-Wind detection of GRB 260207B
  100. GRB 260128B: SVOM/ECLAIRs refined analysis

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov