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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"

19215 results found.

  1. GRB 260914A: SVOM/VT optical observation from VHF data
  2. GRB 260914A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  3. SVOM GRB260914.47: Global MASTER-Net observations report
  4. GRB 260914A: SVOM detection of a burst
  5. GRB 260913A: SVOM trigger sb26091302 is not an astrophysical event
  6. GRB 260818A: Continued ATCA observations
  7. SVOM GRB260913.32: Global MASTER-Net observations report
  8. GRB 260913A: SVOM/C-GFT optical upper limit
  9. GRB 260913A: SVOM detection of a faint burst
  10. GRB 260907A: SVOM/GRM observation
  11. GRB 260909A: CrAO and AbAO optical upper limits
  12. GRB 260909A: SVOM/ECLAIRs refined analysis
  13. GRB 260910B: GOTO tentative optical counterpart candidates
  14. GRB 260910B: Fermi GBM Final Real-time Localization
  15. GRB 260903A: Swift-XRT observations
  16. EP260806a: VLA+ALMA radio detections
  17. GRB 260909A: OHP/T193 z-band upper limit
  18. GRB 260909A: VLT optical and near-infrared upper limits
  19. EP Alert 260909.53: Global MASTER-Net observations report
  20. GRB 260909A: EP-FXT follow-up observation
  21. GRB 260910A: Fermi GBM Final Real-time Localization
  22. EP260806a: NOEMA detection
  23. GRB 260909A: SVOM/VT optical upper limits
  24. GRB 260909A: SVOM/GRM observation
  25. GRB 260909A: Mondy optical observations and afterglow candidate
  26. GRB 260909A: Xinglong 2.16m optical upper limit
  27. GRB 260909A: SVOM/C-GFT optical upper limit
  28. GRB 260909A: SVOM detection of a burst
  29. Fermi trigger No 810554827: Global MASTER-Net observations report
  30. EP Alert 260908.60: Global MASTER-Net observations report
  31. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  32. Fermi GRB 260907B: Global MASTER-Net observations report
  33. GRB 260903A: SAO RAS optical upper limit
  34. The EP-WXT trigger 01709305715 is likely a flaring star
  35. GRB 260907B: Fermi GBM Final Real-time Localization
  36. Fermi GRB 260907A: Global MASTER-Net observations report
  37. GRB 260907A: Fermi GBM Final Real-time Localization
  38. EP260903a: EP-FXT follow-up observation
  39. EP Alert 260905.11: Global MASTER-Net observations report
  40. The EP-WXT trigger 01709302592 is likely a flaring star
  41. GRB 260903A: J-band upper limit with WINTER
  42. EP Alert 260903.47: Global MASTER-Net observations report
  43. GRB 260903A: SVOM/ECLAIRs refined analysis
  44. GRB260903A: Liverpool Telescope optical observations
  45. GRB 260903A: SAO RAS optical observations
  46. GRB 260830A: GECAM-B detection of a burst
  47. EP260903a: EP-WXT detection of a fast X-ray transient
  48. EP Alert 260903.62: Global MASTER-Net observations report
  49. GRB 260830A: Insight-HXMT/HE detection
  50. GRB 260903A: EP-FXT follow-up observation
  51. GRB 260903A: NOT optical observations and afterglow fading
  52. NuSTAR Transient 260828: SOAR Optical Upper Limits
  53. SVOM GRB260903A: Global MASTER-Net observations report
  54. GRB 260903A: SVOM/VT optical candidate
  55. GRB 260903A: Retraction of optical counterpart of GCN 45501
  56. GRB 260831A: GECAM-B observation
  57. GRB 260903A: LCO optical counterpart detection
  58. GRB 260827A: Insight-HXMT/HE detection
  59. GRB 260903A: SVOM detection of a soft faint burst
  60. EP260901a: SVOM/VT optical upper limits
  61. EP260901a: EP-FXT follow-up observation
  62. GRB 260829A: SVOM/GRM observation
  63. GRB 260818A: ATCA detection of a candidate radio counterpart
  64. EP260830a: EP-FXT follow-up observation
  65. EP260901a: Global MASTER-Net observations report
  66. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  67. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  68. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  69. NuSTAR Transient 260828: LCO Optical Upper Limits
  70. EP260901a: EP-WXT detection of a fast X-ray transient
  71. SVOM trigger sb26083106 is not a GRB
  72. GRB 260829A: AstroSat CZTI detection
  73. GRB 260831B: EP-FXT follow-up observation
  74. GRB 260830A: NuSTAR detection of prompt emission
  75. GRB 260831B: LCO optical upper limits
  76. EP260830a: Global MASTER-Net observations report
  77. EP260830a: EP-WXT detection of a fast X-ray transient
  78. GRB 260827A: SVOM/GRM observation
  79. NuSTAR 260828: a 1100s hard X-ray transient
  80. GRB 260831B: SVOM detection of a possible burst
  81. GRB 260827A: Glowbug gamma-ray detection
  82. EP260727a: ATCA 10 GHz detection
  83. GRB 260831A: Fermi GBM Final Real-time Localization
  84. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  85. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  86. GRB 260829A: GECAM-B observation of a long burst
  87. GRB 260825A: SVOM/GRM observation of a long burst
  88. GRB 260825A: GECAM-B observation
  89. GRB 260829A: Fermi GBM Detection
  90. GRB 260825A: AstroSat CZTI detection
  91. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  92. GRB 260829A: Fermi GBM Final Real-time Localization
  93. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  94. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  95. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  96. Fermi GBM trigger 809666623/260829141 is not a GRB
  97. GRB 260818B: Further EP-FXT observation
  98. GRB 260818B: TNG NIR observations
  99. MAXI GRB260827.40: Global MASTER-Net observations report
  100. The EP-WXT trigger 01709291839 is likely the known LMXB 4U 1745-203

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