Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

2406 results found.

  1. GRB 260827A: Insight-HXMT/HE detection
  2. GRB 260903A: SVOM detection of a soft faint burst
  3. EP260901a: SVOM/VT optical upper limits
  4. Konus-Wind detection of GRB 260829A
  5. GRB 260829A: SVOM/GRM observation
  6. GRB 260818A: ATCA detection of a candidate radio counterpart
  7. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  8. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  9. SVOM trigger sb26083106 is not a GRB
  10. GRB 260831B: EP-FXT follow-up observation
  11. GRB 260831B: LCO optical upper limits
  12. GRB 260827A: SVOM/GRM observation
  13. GRB 260831B: SVOM detection of a possible burst
  14. GRB 260825A: SVOM/GRM observation of a long burst
  15. GRB 260818B: Further EP-FXT observation
  16. GRB 260818B: VLT optical and nIR observations
  17. GRB 260818B: TNG NIR observations
  18. GRB 260818B: 6 GHz VLA observations
  19. GRB 260818B: SVOM/VT optical upper limit and continuous observations
  20. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  21. GRB 260808B: SAO RAS observations of the optical rebrightening
  22. GRB 260807A: EP-FXT follow-up observations
  23. GRB 260822A: SVOM/ECLAIRs refined analysis
  24. GRB 260809A: SVOM/ECLAIRs refined analysis
  25. GRB 260822A: SVOM/VT optical upper limits
  26. GRB 260822A: PRIME near-infrared upper limits from multiple epochs
  27. GRB 260822A: EP/FXT follow-up observations
  28. GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
  29. GRB 260818A: further EP-FXT observations and X-ray afterglow confirmation
  30. GRB 260822A: GOTO optical counterpart detection
  31. GRB 260822A: SVOM/VT optical detection of COLIBRÍ candidate
  32. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  33. GRB 260822A: LCO optical upper limits
  34. GRB 260822A: GROWTH-India Telescope Upper Limits
  35. GRB 260822A: GOTO optical upper limit
  36. GRB 260822A: SVOM detection of a short burst
  37. GRB 260818B: SVOM/C-GFT optical upper limit
  38. EP260731a: SVOM/ECLAIRs detection through offline targeted search
  39. GRB 260818B: SVOM/GRM observation
  40. GRB 260818B: Insight-HXMT detection
  41. GRB 260818B: EP-FXT follow-up observation
  42. GRB 260818A: J-band observations with WINTER
  43. GRB 260818B: SVOM/ECLAIRs refined analysis
  44. GRB 260818A: SVOM/ECLAIRs refined analysis
  45. GRB 260818B: NOT optical upper limits
  46. GRB 260810A: SVOM/GRM observation
  47. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  48. GRB260818A: EP-FXT follow-up observation
  49. GRB 260818B: LCO optical upper limits
  50. GRB 260818B: SVOM detection of a short burst
  51. SVOM trigger sb26081806 is not a GRB
  52. GRB 260818A: LCO optical upper limits
  53. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  54. GRB 260818A: SVOM possible detection of a long and faint GRB
  55. EP260806a: SVOM/ECLAIRs detection through targeted search
  56. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  57. GRB 260808B: Liverpool Telescope further optical observations
  58. EP260812a: SVOM/C-GFT optical upper limit
  59. EP260812b: COLIBRÍ optical observations
  60. EP260812b: SVOM/VT optical observation
  61. GRB 260808A: SVOM/GRM observation
  62. Fermi GBM Sub-Threshold Detection of GRB 260809A
  63. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  64. GRB 260809A: SAO RAS optical observations
  65. GRB 260808B: SAO RAS optical observations
  66. GRB 260808B: SVOM/VT optical re-brightening at day 3
  67. GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
  68. GRB 260807A: SVOM/ECLAIRs refined analysis
  69. GRB260808B: MAO/AZT-22 optical observations
  70. GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
  71. GRB 260809A: J-band upper limit with WINTER
  72. GRB260809A/EPF_J234751.2+210212: EP-FXT follow-up observation
  73. GRB 260809A: SVOM/COLIBRÍ (FM-GFT) optical observation
  74. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
  75. GRB 260809A: NOT optical observations
  76. GRB260809A: MAO/AZT-22 optical observations
  77. GRB 260809A: SVOM/VT optical counterpart
  78. GRB 260808B: J-band upper limit with WINTER
  79. GRB 260808B: SVOM/ECLAIRs refined analysis
  80. GRB 260809A: SVOM detection of a faint burst
  81. GRB 260808B: Liverpool Telescope optical observations
  82. GRB 260808B: NOT optical observations
  83. GRB 260808B: LCO optical observations
  84. GRB 260808B / EPF_J230056.0+082842: EP-FXT follow-up observation
  85. GRB 260808B: SVOM/VT optical afterglow confirmation
  86. GRB 260808B: SVOM/VT optical candidate from VHF data ( localization correction for GCN 45317 )
  87. GRB 260808B: SVOM/VT optical candidate from VHF data
  88. GRB 260808B: SVOM detection of a faint burst
  89. GRB 260807A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  90. GRB 260807A: SVOM possible detection of a faint burst
  91. EP260806a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  92. EP260806a: SVOM/VT optical observation
  93. GRB 260709A: cubesat Avion detection
  94. GRB 260708A: LCO further optical observations show supernova features
  95. GRB 260802A / EP J223759.5+521421: EP-FXT follow-up observation
  96. GRB 260802A / EP J223759.5+531421: SVOM/VT optical upper limit
  97. GRB 260802A: SVOM/VT optical upper limits from VHF data
  98. GRB 260802A: LCO optical upper limits
  99. GRB 260802A / EP J223759.5+531421: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  100. GRB 260802A/EP J223759.5+531421: SVOM detection of a possible magnetar burst

Advanced

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