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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"

19212 results found.

  1. GRB 260914A: SVOM detection of a burst
  2. GRB 260913A: SVOM trigger sb26091302 is not an astrophysical event
  3. GRB 260818A: Continued ATCA observations
  4. SVOM GRB260913.32: Global MASTER-Net observations report
  5. GRB 260913A: SVOM/C-GFT optical upper limit
  6. GRB 260913A: SVOM detection of a faint burst
  7. GRB 260907A: SVOM/GRM observation
  8. GRB 260909A: CrAO and AbAO optical upper limits
  9. GRB 260909A: SVOM/ECLAIRs refined analysis
  10. GRB 260910B: GOTO tentative optical counterpart candidates
  11. GRB 260910B: Fermi GBM Final Real-time Localization
  12. GRB 260903A: Swift-XRT observations
  13. EP260806a: VLA+ALMA radio detections
  14. GRB 260909A: OHP/T193 z-band upper limit
  15. GRB 260909A: VLT optical and near-infrared upper limits
  16. EP Alert 260909.53: Global MASTER-Net observations report
  17. GRB 260909A: EP-FXT follow-up observation
  18. GRB 260910A: Fermi GBM Final Real-time Localization
  19. EP260806a: NOEMA detection
  20. GRB 260909A: SVOM/VT optical upper limits
  21. GRB 260909A: SVOM/GRM observation
  22. GRB 260909A: Mondy optical observations and afterglow candidate
  23. GRB 260909A: Xinglong 2.16m optical upper limit
  24. GRB 260909A: SVOM/C-GFT optical upper limit
  25. GRB 260909A: SVOM detection of a burst
  26. Fermi trigger No 810554827: Global MASTER-Net observations report
  27. EP Alert 260908.60: Global MASTER-Net observations report
  28. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  29. Fermi GRB 260907B: Global MASTER-Net observations report
  30. GRB 260903A: SAO RAS optical upper limit
  31. The EP-WXT trigger 01709305715 is likely a flaring star
  32. GRB 260907B: Fermi GBM Final Real-time Localization
  33. Fermi GRB 260907A: Global MASTER-Net observations report
  34. GRB 260907A: Fermi GBM Final Real-time Localization
  35. EP260903a: EP-FXT follow-up observation
  36. EP Alert 260905.11: Global MASTER-Net observations report
  37. The EP-WXT trigger 01709302592 is likely a flaring star
  38. GRB 260903A: J-band upper limit with WINTER
  39. EP Alert 260903.47: Global MASTER-Net observations report
  40. GRB 260903A: SVOM/ECLAIRs refined analysis
  41. GRB260903A: Liverpool Telescope optical observations
  42. GRB 260903A: SAO RAS optical observations
  43. GRB 260830A: GECAM-B detection of a burst
  44. EP260903a: EP-WXT detection of a fast X-ray transient
  45. EP Alert 260903.62: Global MASTER-Net observations report
  46. GRB 260830A: Insight-HXMT/HE detection
  47. GRB 260903A: EP-FXT follow-up observation
  48. GRB 260903A: NOT optical observations and afterglow fading
  49. NuSTAR Transient 260828: SOAR Optical Upper Limits
  50. SVOM GRB260903A: Global MASTER-Net observations report
  51. GRB 260903A: SVOM/VT optical candidate
  52. GRB 260903A: Retraction of optical counterpart of GCN 45501
  53. GRB 260831A: GECAM-B observation
  54. GRB 260903A: LCO optical counterpart detection
  55. GRB 260827A: Insight-HXMT/HE detection
  56. GRB 260903A: SVOM detection of a soft faint burst
  57. EP260901a: SVOM/VT optical upper limits
  58. EP260901a: EP-FXT follow-up observation
  59. GRB 260829A: SVOM/GRM observation
  60. GRB 260818A: ATCA detection of a candidate radio counterpart
  61. EP260830a: EP-FXT follow-up observation
  62. EP260901a: Global MASTER-Net observations report
  63. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  64. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  65. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  66. NuSTAR Transient 260828: LCO Optical Upper Limits
  67. EP260901a: EP-WXT detection of a fast X-ray transient
  68. SVOM trigger sb26083106 is not a GRB
  69. GRB 260829A: AstroSat CZTI detection
  70. GRB 260831B: EP-FXT follow-up observation
  71. GRB 260830A: NuSTAR detection of prompt emission
  72. GRB 260831B: LCO optical upper limits
  73. EP260830a: Global MASTER-Net observations report
  74. EP260830a: EP-WXT detection of a fast X-ray transient
  75. GRB 260827A: SVOM/GRM observation
  76. NuSTAR 260828: a 1100s hard X-ray transient
  77. GRB 260831B: SVOM detection of a possible burst
  78. GRB 260827A: Glowbug gamma-ray detection
  79. EP260727a: ATCA 10 GHz detection
  80. GRB 260831A: Fermi GBM Final Real-time Localization
  81. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  82. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  83. GRB 260829A: GECAM-B observation of a long burst
  84. GRB 260825A: SVOM/GRM observation of a long burst
  85. GRB 260825A: GECAM-B observation
  86. GRB 260829A: Fermi GBM Detection
  87. GRB 260825A: AstroSat CZTI detection
  88. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  89. GRB 260829A: Fermi GBM Final Real-time Localization
  90. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  91. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  92. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  93. Fermi GBM trigger 809666623/260829141 is not a GRB
  94. GRB 260818B: Further EP-FXT observation
  95. GRB 260818B: TNG NIR observations
  96. MAXI GRB260827.40: Global MASTER-Net observations report
  97. The EP-WXT trigger 01709291839 is likely the known LMXB 4U 1745-203
  98. GRB 260827A: Fermi GBM Final Real-time Localization
  99. GRB 260818B: 6 GHz VLA observations
  100. GRB 260818B: SVOM/VT optical upper limit and continuous observations

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