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"

962 results found.

  1. GRB 260907A: SVOM/GRM observation
  2. GRB 260909A: SVOM/ECLAIRs refined analysis
  3. GRB 260909A: SVOM/VT optical upper limits
  4. GRB 260909A: SVOM/GRM observation
  5. GRB 260909A: SVOM/C-GFT optical upper limit
  6. GRB 260909A: SVOM detection of a burst
  7. GRB 260903A: SVOM/ECLAIRs refined analysis
  8. GRB 260903A: LCO optical observations
  9. GRB 260903A: SVOM/VT optical candidate
  10. GRB 260903A: Retraction of optical counterpart of GCN 45501
  11. GRB 260903A: LCO optical counterpart detection
  12. GRB 260903A: SVOM detection of a soft faint burst
  13. EP260901a: SVOM/VT optical upper limits
  14. GRB 260829A: SVOM/GRM observation
  15. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  16. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  17. SVOM trigger sb26083106 is not a GRB
  18. GRB 260831B: LCO optical upper limits
  19. GRB 260827A: SVOM/GRM observation
  20. GRB 260831B: SVOM detection of a possible burst
  21. GRB 260825A: SVOM/GRM observation of a long burst
  22. GRB 260818B: SVOM/VT optical upper limit and continuous observations
  23. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  24. GRB 260807A: EP-FXT follow-up observations
  25. GRB 260822A: SVOM/ECLAIRs refined analysis
  26. GRB 260809A: SVOM/ECLAIRs refined analysis
  27. GRB 260822A: SVOM/VT optical upper limits
  28. GRB 260822A: EP/FXT follow-up observations
  29. GRB 260818A: further EP-FXT observations and X-ray afterglow confirmation
  30. GRB 260822A: SVOM/VT optical detection of COLIBRÍ candidate
  31. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  32. GRB 260822A: LCO optical upper limits
  33. GRB 260822A: SVOM detection of a short burst
  34. GRB 260818B: SVOM/C-GFT optical upper limit
  35. EP260731a: SVOM/ECLAIRs detection through offline targeted search
  36. GRB 260818B: SVOM/GRM observation
  37. GRB 260818B: SVOM/ECLAIRs refined analysis
  38. GRB 260818A: SVOM/ECLAIRs refined analysis
  39. GRB 260810A: SVOM/GRM observation
  40. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  41. GRB 260818B: LCO optical upper limits
  42. GRB 260818B: SVOM detection of a short burst
  43. GRB 260818A: LCO optical upper limits
  44. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  45. GRB 260818A: SVOM possible detection of a long and faint GRB
  46. EP260806a: SVOM/ECLAIRs detection through targeted search
  47. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  48. EP260812a: SVOM/C-GFT optical upper limit
  49. EP260812b: SVOM/VT optical observation
  50. GRB 260808A: SVOM/GRM observation
  51. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  52. GRB 260808B: SVOM/VT optical re-brightening at day 3
  53. GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
  54. GRB 260807A: SVOM/ECLAIRs refined analysis
  55. GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
  56. GRB 260809A: SVOM/COLIBRÍ (FM-GFT) optical observation
  57. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
  58. GRB 260809A: SVOM/VT optical counterpart
  59. GRB 260808B: SVOM/ECLAIRs refined analysis
  60. GRB 260809A: SVOM detection of a faint burst
  61. GRB 260808B: LCO optical observations
  62. GRB 260808B: SVOM/VT optical afterglow confirmation
  63. GRB 260808B: SVOM/VT optical candidate from VHF data ( localization correction for GCN 45317 )
  64. GRB 260808B: SVOM/VT optical candidate from VHF data
  65. GRB 260808B: SVOM detection of a faint burst
  66. GRB 260807A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  67. GRB 260807A: SVOM possible detection of a faint burst
  68. EP260806a: SVOM/VT optical observation
  69. GRB 260708A: LCO further optical observations show supernova features
  70. GRB 260802A / EP J223759.5+531421: SVOM/VT optical upper limit
  71. GRB 260802A: SVOM/VT optical upper limits from VHF data
  72. GRB 260802A: LCO optical upper limits
  73. GRB 260802A / EP J223759.5+531421: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  74. GRB 260802A/EP J223759.5+531421: SVOM detection of a possible magnetar burst
  75. GRB 260727A: EP-FXT further follow-up observations and candidate afterglow
  76. GRB 260618B: SVOM/VT continued optical observations indicated a steeper and redder decay
  77. GRB 260727A: SVOM/ECLAIRs refined analysis
  78. GRB 260726A: SVOM/ECLAIRs refined analysis
  79. GRB 260726A: EP-FXT follow-up observations
  80. GRB 260727A: SVOM/GRM observation
  81. GRB 260727A: EP/FXT follow-up observations
  82. GRB 260726A: SVOM/VT optical candidate
  83. GRB 260726A: SVOM ECLAIRs improved position and MXT possible detection of a counterpart
  84. EP260723a: SVOM/ECLAIRs Upper Limit
  85. GRB 260727A: LCO optical upper limits
  86. GRB 260727A: SVOM detection of a bright long burst
  87. GRB 260726A: SVOM detection of a burst
  88. GRB 260718A: SVOM/ECLAIRs refined analysis
  89. EP260723a: SVOM/VT optical observation
  90. SVOM trigger sb26071506: SVOM/VT confirmation of a stellar flare
  91. GRB 260718A: LCO optical upper limits
  92. GRB 260711A: SVOM/GRM observation
  93. GRB 260710A: SVOM/GRM observation
  94. GRB 260718A: SVOM/VT optical upper limits
  95. GRB 260718A: SVOM/VT optical upper limits from VHF data
  96. GRB 260718A: SVOM detection of a burst
  97. GRB 260714B: SVOM/GRM observation
  98. sb26071506: SVOM detection of a X-ray transient
  99. EP260703a: SVOM/ECLAIRs Upper Limit
  100. GRB 260619A: SVOM/VT continuous optical observations

Advanced

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