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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"

19209 results found.

  1. SVOM GRB260913.32: Global MASTER-Net observations report
  2. GRB 260913A: SVOM/C-GFT optical upper limit
  3. GRB 260913A: SVOM detection of a faint burst
  4. GRB 260907A: SVOM/GRM observation
  5. GRB 260909A: CrAO and AbAO optical upper limits
  6. GRB 260909A: SVOM/ECLAIRs refined analysis
  7. GRB 260910B: GOTO tentative optical counterpart candidates
  8. GRB 260910B: Fermi GBM Final Real-time Localization
  9. GRB 260903A: Swift-XRT observations
  10. EP260806a: VLA+ALMA radio detections
  11. GRB 260909A: OHP/T193 z-band upper limit
  12. GRB 260909A: VLT optical and near-infrared upper limits
  13. EP Alert 260909.53: Global MASTER-Net observations report
  14. GRB 260909A: EP-FXT follow-up observation
  15. GRB 260910A: Fermi GBM Final Real-time Localization
  16. EP260806a: NOEMA detection
  17. GRB 260909A: SVOM/VT optical upper limits
  18. GRB 260909A: SVOM/GRM observation
  19. GRB 260909A: Mondy optical observations and afterglow candidate
  20. GRB 260909A: Xinglong 2.16m optical upper limit
  21. GRB 260909A: SVOM/C-GFT optical upper limit
  22. GRB 260909A: SVOM detection of a burst
  23. Fermi trigger No 810554827: Global MASTER-Net observations report
  24. EP Alert 260908.60: Global MASTER-Net observations report
  25. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  26. Fermi GRB 260907B: Global MASTER-Net observations report
  27. GRB 260903A: SAO RAS optical upper limit
  28. The EP-WXT trigger 01709305715 is likely a flaring star
  29. GRB 260907B: Fermi GBM Final Real-time Localization
  30. Fermi GRB 260907A: Global MASTER-Net observations report
  31. GRB 260907A: Fermi GBM Final Real-time Localization
  32. EP260903a: EP-FXT follow-up observation
  33. EP Alert 260905.11: Global MASTER-Net observations report
  34. The EP-WXT trigger 01709302592 is likely a flaring star
  35. GRB 260903A: J-band upper limit with WINTER
  36. EP Alert 260903.47: Global MASTER-Net observations report
  37. GRB 260903A: SVOM/ECLAIRs refined analysis
  38. GRB260903A: Liverpool Telescope optical observations
  39. GRB 260903A: SAO RAS optical observations
  40. GRB 260830A: GECAM-B detection of a burst
  41. EP260903a: EP-WXT detection of a fast X-ray transient
  42. EP Alert 260903.62: Global MASTER-Net observations report
  43. GRB 260830A: Insight-HXMT/HE detection
  44. GRB 260903A: EP-FXT follow-up observation
  45. GRB 260903A: NOT optical observations and afterglow fading
  46. NuSTAR Transient 260828: SOAR Optical Upper Limits
  47. SVOM GRB260903A: Global MASTER-Net observations report
  48. GRB 260903A: SVOM/VT optical candidate
  49. GRB 260903A: Retraction of optical counterpart of GCN 45501
  50. GRB 260831A: GECAM-B observation
  51. GRB 260903A: LCO optical counterpart detection
  52. GRB 260827A: Insight-HXMT/HE detection
  53. GRB 260903A: SVOM detection of a soft faint burst
  54. EP260901a: SVOM/VT optical upper limits
  55. EP260901a: EP-FXT follow-up observation
  56. GRB 260829A: SVOM/GRM observation
  57. GRB 260818A: ATCA detection of a candidate radio counterpart
  58. EP260830a: EP-FXT follow-up observation
  59. EP260901a: Global MASTER-Net observations report
  60. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  61. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  62. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  63. NuSTAR Transient 260828: LCO Optical Upper Limits
  64. EP260901a: EP-WXT detection of a fast X-ray transient
  65. SVOM trigger sb26083106 is not a GRB
  66. GRB 260829A: AstroSat CZTI detection
  67. GRB 260831B: EP-FXT follow-up observation
  68. GRB 260830A: NuSTAR detection of prompt emission
  69. GRB 260831B: LCO optical upper limits
  70. EP260830a: Global MASTER-Net observations report
  71. EP260830a: EP-WXT detection of a fast X-ray transient
  72. GRB 260827A: SVOM/GRM observation
  73. NuSTAR 260828: a 1100s hard X-ray transient
  74. GRB 260831B: SVOM detection of a possible burst
  75. GRB 260827A: Glowbug gamma-ray detection
  76. EP260727a: ATCA 10 GHz detection
  77. GRB 260831A: Fermi GBM Final Real-time Localization
  78. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  79. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  80. GRB 260829A: GECAM-B observation of a long burst
  81. GRB 260825A: SVOM/GRM observation of a long burst
  82. GRB 260825A: GECAM-B observation
  83. GRB 260829A: Fermi GBM Detection
  84. GRB 260825A: AstroSat CZTI detection
  85. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  86. GRB 260829A: Fermi GBM Final Real-time Localization
  87. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  88. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  89. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  90. Fermi GBM trigger 809666623/260829141 is not a GRB
  91. GRB 260818B: Further EP-FXT observation
  92. GRB 260818B: TNG NIR observations
  93. MAXI GRB260827.40: Global MASTER-Net observations report
  94. The EP-WXT trigger 01709291839 is likely the known LMXB 4U 1745-203
  95. GRB 260827A: Fermi GBM Final Real-time Localization
  96. GRB 260818B: 6 GHz VLA observations
  97. GRB 260818B: SVOM/VT optical upper limit and continuous observations
  98. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  99. GRB 260808B: SAO RAS observations of the optical rebrightening
  100. EP260822a: Global MASTER-Net observations report

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