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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"

2262 results found.

  1. MAXI GRB260916.37: Global MASTER-Net observations report
  2. GRB 260915A: J-band upper limit by SYSU 80cm infrared telescope
  3. GRB 260915A: SVOM/C-GFT optical upper limits
  4. GRB 260915A: EP-FXT follow-up observation
  5. GRB 260915A: REM optical/NIR observations
  6. GRB 260914A: REM optical/NIR observations
  7. GRB 260914A: VLT/X-shooter observations and redshift confirmation
  8. GRB 260915A: SVOM/VT optical upper limits
  9. GRB 260915A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  10. GRB 260914A: VLT/X-shooter spectroscopic redshift z = 0.778
  11. GRB 260915A: NOT optical upper limit
  12. SVOM GRB260915.05: Global MASTER-Net observations report
  13. GRB 260915A: SVOM/VT optical upper limits from VHF data
  14. Fermi GBM Sub-Threshold Detection of GRB 260915A
  15. GRB 260915A: LCO optical upper limits
  16. EP Alert 260914.53: Global MASTER-Net observations report
  17. GRB 260914A: EP-FXT follow-up observation
  18. GRB 260915A: SVOM detection of a burst
  19. Fermi GBM Sub-Threshold Detection of GRB 260914A
  20. GRB 260914A: LCO optical observation
  21. GRB 260914A: SVOM/C-GFT optical observations
  22. GRB 260914A: SVOM/VT optical counterpart confirmation
  23. GRB 260914A: SVOM/VT optical observation from VHF data
  24. GRB 260914A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  25. SVOM GRB260914.47: Global MASTER-Net observations report
  26. GRB 260914A: SVOM detection of a burst
  27. GRB 260913A: SVOM trigger sb26091302 is not an astrophysical event
  28. GRB 260818A: Continued ATCA observations
  29. SVOM GRB260913.32: Global MASTER-Net observations report
  30. GRB 260913A: SVOM/C-GFT optical upper limit
  31. GRB 260913A: SVOM detection of a faint burst
  32. GRB 260907A: SVOM/GRM observation
  33. GRB 260909A: CrAO and AbAO optical upper limits
  34. GRB 260909A: SVOM/ECLAIRs refined analysis
  35. GRB 260910B: GOTO tentative optical counterpart candidates
  36. GRB 260910B: Fermi GBM Final Real-time Localization
  37. EP260806a: VLA+ALMA radio detections
  38. GRB 260909A: OHP/T193 z-band upper limit
  39. GRB 260909A: VLT optical and near-infrared upper limits
  40. EP Alert 260909.53: Global MASTER-Net observations report
  41. GRB 260909A: EP-FXT follow-up observation
  42. GRB 260910A: Fermi GBM Final Real-time Localization
  43. EP260806a: NOEMA detection
  44. GRB 260909A: SVOM/VT optical upper limits
  45. GRB 260909A: SVOM/GRM observation
  46. GRB 260909A: Mondy optical observations and afterglow candidate
  47. GRB 260909A: Xinglong 2.16m optical upper limit
  48. GRB 260909A: SVOM/C-GFT optical upper limit
  49. GRB 260909A: SVOM detection of a burst
  50. Fermi trigger No 810554827: Global MASTER-Net observations report
  51. EP Alert 260908.60: Global MASTER-Net observations report
  52. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  53. Fermi GRB 260907B: Global MASTER-Net observations report
  54. GRB 260903A: SAO RAS optical upper limit
  55. The EP-WXT trigger 01709305715 is likely a flaring star
  56. GRB 260907B: Fermi GBM Final Real-time Localization
  57. Fermi GRB 260907A: Global MASTER-Net observations report
  58. GRB 260907A: Fermi GBM Final Real-time Localization
  59. EP260903a: EP-FXT follow-up observation
  60. EP Alert 260905.11: Global MASTER-Net observations report
  61. The EP-WXT trigger 01709302592 is likely a flaring star
  62. GRB 260903A: J-band upper limit with WINTER
  63. EP Alert 260903.47: Global MASTER-Net observations report
  64. GRB 260903A: SVOM/ECLAIRs refined analysis
  65. GRB260903A: Liverpool Telescope optical observations
  66. GRB 260903A: SAO RAS optical observations
  67. GRB 260830A: GECAM-B detection of a burst
  68. EP260903a: EP-WXT detection of a fast X-ray transient
  69. EP Alert 260903.62: Global MASTER-Net observations report
  70. GRB 260830A: Insight-HXMT/HE detection
  71. GRB 260903A: EP-FXT follow-up observation
  72. GRB 260903A: NOT optical observations and afterglow fading
  73. NuSTAR Transient 260828: SOAR Optical Upper Limits
  74. SVOM GRB260903A: Global MASTER-Net observations report
  75. GRB 260903A: SVOM/VT optical candidate
  76. GRB 260831A: GECAM-B observation
  77. GRB 260903A: LCO optical counterpart detection
  78. GRB 260827A: Insight-HXMT/HE detection
  79. GRB 260903A: SVOM detection of a soft faint burst
  80. EP260901a: SVOM/VT optical upper limits
  81. EP260901a: EP-FXT follow-up observation
  82. GRB 260829A: SVOM/GRM observation
  83. GRB 260818A: ATCA detection of a candidate radio counterpart
  84. EP260830a: EP-FXT follow-up observation
  85. EP260901a: Global MASTER-Net observations report
  86. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  87. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  88. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  89. NuSTAR Transient 260828: LCO Optical Upper Limits
  90. EP260901a: EP-WXT detection of a fast X-ray transient
  91. SVOM trigger sb26083106 is not a GRB
  92. GRB 260829A: AstroSat CZTI detection
  93. GRB 260831B: EP-FXT follow-up observation
  94. GRB 260830A: NuSTAR detection of prompt emission
  95. GRB 260831B: LCO optical upper limits
  96. EP260830a: Global MASTER-Net observations report
  97. EP260830a: EP-WXT detection of a fast X-ray transient
  98. GRB 260827A: SVOM/GRM observation
  99. NuSTAR 260828: a 1100s hard X-ray transient
  100. GRB 260831B: SVOM detection of a possible burst

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