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"

19402 results found.

  1. GRB 260822A: PRIME near-infrared upper limits from multiple epochs
  2. GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
  3. EP260822a: EP-FXT non-detection and upper limit
  4. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  5. EP260822a: Einstein Probe detection of a fast X-ray transient
  6. GRB 260822A: LCO optical upper limits
  7. GRB 260822A: GROWTH-India Telescope Upper Limits
  8. GRB 260822A: SVOM detection of a short burst
  9. GRB 260818B: SVOM/C-GFT optical upper limit
  10. EP260731a: SVOM/ECLAIRs detection through offline targeted search
  11. EP detected a brightening of LMXB 1ES 1735-26.9
  12. GRB 260818A: J-band observations with WINTER
  13. GRB 260818B: SVOM/ECLAIRs refined analysis
  14. GRB 260818A: SVOM/ECLAIRs refined analysis
  15. GRB 260818B: NOT optical upper limits
  16. GRB 260810A: SVOM/GRM observation
  17. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  18. GRB 260818B: LCO optical upper limits
  19. GRB 260818B: SVOM detection of a short burst
  20. EP260806a: SAO RAS multicolor optical observations
  21. GRB 260818A: LCO optical upper limits
  22. EP260812a: AbAO optical upper limit
  23. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  24. GRB 260818A: SVOM possible detection of a long and faint GRB
  25. EP260806a: NUTTELA-TAO optical observations
  26. EP260812a: AZT-22 optical upper limit
  27. EP260806a: WFST optical observations
  28. EP260812b: Optical upper limit with Kinder
  29. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  30. GRB 260808B: Liverpool Telescope further optical observations
  31. EP260812a: NOT and Liverpool Telescope upper limits:
  32. EP260812b: Liverpool Telescope observations
  33. EP260812a: refined analysis of the EP-WXT and autonomous EP-FXT observation
  34. EP260812a: SVOM/C-GFT optical upper limit
  35. EP260812b: COLIBRÍ optical observations
  36. EP260812b: SVOM/VT optical observation
  37. GRB 260808A: SVOM/GRM observation
  38. EP260812b: Einstein Probe detection of an X-ray transient
  39. EP trigger #01709278129 (EP260812b?): NOT optical counterpart
  40. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  41. EP260812a: Einstein Probe detection of an X-ray transient
  42. GRB 260809A: SAO RAS optical observations
  43. GRB 260808B: SAO RAS optical observations
  44. GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
  45. GRB 260807A: SVOM/ECLAIRs refined analysis
  46. EP260806a: MAO/AZT-22 optical observations
  47. GRB260808B: MAO/AZT-22 optical observations
  48. GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
  49. GRB 260809A: J-band upper limit with WINTER
  50. GRB 260808A: CALET Gamma-Ray Burst Monitor detection
  51. GRB 260809A: SVOM/COLIBRÍ (FM-GFT) optical observation
  52. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
  53. GRB 260809A: NOT optical observations
  54. GRB260809A: MAO/AZT-22 optical observations
  55. GRB260809A: OHP/T193 optical observations
  56. EP260809a: J-band upper limit with WINTER
  57. GRB 260808B: J-band upper limit with WINTER
  58. GRB 260808B: SVOM/ECLAIRs refined analysis
  59. EP260809a:refined analysis of the EP-WXT and autonomous EP-FXT observation
  60. GRB 260809A: SVOM detection of a faint burst
  61. GRB 260808B: Liverpool Telescope optical observations
  62. GRB 260808B: NOT optical observations
  63. GRB 260808B: LCO optical observations
  64. EP260809a: COLIBRÍ optical observations
  65. EP260809a: LCO optical observation
  66. EP260809a: OHP/T193 optical observations
  67. GRB260808B: OHP/T193 optical observations
  68. EP260809a: Einstein Probe detection of an X-ray transient
  69. GRB 260808B: SVOM/VT optical afterglow confirmation
  70. GRB 260808C: Fermi GBM Final Real-time Localization
  71. GRB 260808B: SVOM/VT optical candidate from VHF data ( localization correction for GCN 45317 )
  72. GRB 260808B: SVOM/VT optical candidate from VHF data
  73. GRB 260808B: SVOM detection of a faint burst
  74. GRB 260808A: Fermi GBM Final Real-time Localization
  75. GRB 260807A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  76. GRB 260807A: SVOM possible detection of a faint burst
  77. EP260806a: COLIBRÍ optical observations
  78. EP260806a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  79. EP260806a: SVOM/VT optical observation
  80. EP260806a: Liverpool Telescope observations of the counterpart show a blue colour
  81. EP260731a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  82. EP260806a: LCO likely optical counterpart
  83. EP260806a: Einstein Probe detection of an X-ray transient
  84. GRB 260802A: SVOM/VT optical upper limits from VHF data
  85. GRB 260802A: LCO optical upper limits
  86. GRB 260802A / EP J223759.5+531421: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  87. GRB 260802A/EP J223759.5+531421: SVOM detection of a possible magnetar burst
  88. GRB 260731A: AstroSat CZTI detection of a long burst
  89. EP260731a: COLIBRÍ optical upper limit
  90. EP260731a: NOT optical upper limit
  91. EP260731a: Einstein Probe detection of an X-ray transient
  92. EP260728a: COLIBRÍ optical upper limit
  93. EP260729a: Einstein Probe detection of an X-ray transient
  94. EP260727a: SAO RAS optical observations
  95. GRB 260727A: AbAO and SAO RAS optical observations
  96. EP260728a: Einstein Probe detection of a fast X-ray transient
  97. EP260727a:refined analysis of the EP-WXT and EP-FXT observation
  98. EP260727a: OHP/T193 optical observations
  99. GRB 260726A: Liverpool Telescope optical observations
  100. GRB 260727A: Liverpool Telescope optical upper limits

Advanced

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