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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"

5862 results found.

  1. LIGO/Virgo S230525a: Global MASTER-Net observations report
  2. Fermi-LAT gamma-ray observations of IceCube-230524A
  3. IceCube-230524A: Upper limits from a search for additional neutrino events in IceCube
  4. IceCube Alert 230524.47: Global MASTER-Net observations report
  5. IceCube-230524A - IceCube observation of a high-energy neutrino candidate track-like event
  6. Fermi trigger No 706610076: Global MASTER-Net observations report
  7. GRB 230523A: Fermi GBM Final Real-time Localization
  8. LIGO/Virgo S230522a: Global MASTER-Net observations report
  9. LIGO/Virgo/KAGRA S230522a: 2 counterpart neutrino candidates from IceCube neutrino searches
  10. LIGO/Virgo S230521k: Global MASTER-Net observations report
  11. LIGO/Virgo S230520ae: Global MASTER-Net observations report
  12. LIGO/Virgo/KAGRA S230520ae: Identification of a GW compact binary merger candidate: End-to-End Test
  13. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  14. GRB 230520A: MAXI/GSC detection
  15. LIGO/Virgo S230518h: Global MASTER-Net observations report
  16. GRB 230512A: Zwicky Transient Facility non-detection of GRB afterglow candidate
  17. GRB 230512A: Kitab possible afterglow candidate
  18. GRB 230506C: Fermi GBM detection
  19. GRB 230506B: LCOGT Optical Upper Limits
  20. GRB 230506C: NUTTelA-TAO / BSTI Early Optical Limits
  21. GRB 230506C: Swift detection of a burst
  22. Fermi trigger No 704837952: Global MASTER-Net observations report
  23. GRB 230427A: TSHAO, SAO RAS, AbAO optical upper limit
  24. Fermi trigger No 704365743: Global MASTER-Net observations report
  25. GRB 230428A: Fermi GBM Final Real-time Localization
  26. Swift Trigger 1165354 is probably not a GRB
  27. GRB 230421A: Fermi GBM observation
  28. GRB 230421: Swift/BAT-GUANO arcminute localization
  29. GRB 230421A: Fermi GBM Final Real-time Localization
  30. GRB 230420A: Swift detection of a burst
  31. GRB 230414B: Osservatorio Astronomico Nastro Verde - Sorrento: optical observations
  32. GRB 230307A: iTelescope optical upper limit (likely)
  33. GRB 230414B: Montarrenti Observatory late time optical afterglow detection
  34. GRB 230414B: Bassano Bresciano Observatory optical observations
  35. GRB 230414B: Enhanced Swift-XRT position
  36. Fermi GRB 230414A: Global MASTER-Net observations report
  37. GRB 230414B: GROWTH India Telescope afterglow confirmation
  38. GRB 230414B: Nanshan/HMT optical afterglow detection
  39. GRB 230414A: Mondy optical afterglow candidate
  40. GRB 230414B: Prompt enhanced Swift-XRT position
  41. GRB 230414B: Swift detection of a burst
  42. GRB 230409B: Mondy optical upper limit
  43. GRB 230409D: VZLUSAT-2 detection
  44. Fermi GRB 230409C: Global MASTER-Net observations report
  45. Fermi GRB 230409A: Global MASTER-Net observations report
  46. Fermi trigger No 702745263: Global MASTER-Net observations report
  47. Swift GRB 230409B: Global MASTER-Net observations report
  48. MAXI GRB230408.82: Global MASTER-Net observations report
  49. Swift GRB 230405B: Global MASTER-Net observations report
  50. GRB 230325A: Swift detection of a burst
  51. Fermi trigger No 701071944: Global MASTER-Net observations report
  52. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  53. Fermi GRB 230316A: Global MASTER-Net observations report
  54. GRB 230307A: INTEGRAL upper limit on Hard X-ray afterglow
  55. Fermi GRB 230313A: Global MASTER-Net observations report
  56. GRB 230309A: AstroSat CZTI detection of a bright long GRB
  57. GRB 230307A: GECKO optical observations and detections of the afterglow
  58. Fermi GRB 230310A: Global MASTER-Net observations report
  59. GRB 230307A: ASO-S/HXI detection
  60. Fermi GRB 230307A: Global MASTER-Net observations report
  61. Fermi GRB 230301B: Global MASTER-Net observations report
  62. Fermi trigger No 699294715: Global MASTER-Net observations report
  63. Fermi GRB 230227A: Global MASTER-Net observations report
  64. Fermi trigger No 699029364: Global MASTER-Net observations report
  65. GRB 230220A: Correction to GCN 33352
  66. GRB 230222A: Fermi GBM Final Real-time Localization
  67. Fermi GRB 230220B: Global MASTER-Net observations report
  68. GRB 230217A: Gemini-South Optical Observation
  69. IceCube Alert 230217.87: Global MASTER-Net observations report
  70. GRB 230217A: Swift detection of a short burst
  71. GRB 230209B: AGILE detection
  72. GRB 230209B: Fermi GBM Observation
  73. Swift Trigger 1153670 is probably not a GRB
  74. Fermi GRB 230209B: Global MASTER-Net observations report
  75. GRB 230209A is not a GRB
  76. Fermi Gamma-ray Burst Monitor trigger 230208382/697540213 is not a GRB
  77. GRB 230208A: Fermi GBM Final Real-time Localization
  78. ZTF23aabmzlp/AT2023azs: Neil Gehrels Swift Observatory X-ray observations
  79. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  80. Fermi trigger No 697098930: Global MASTER-Net observations report
  81. IceCube Alert 230201.26: Global MASTER-Net observations report
  82. Fermi GRB 230201B: Global MASTER-Net observations report
  83. ZTF23aabmzlp/AT2023azs: LCOGT Optical Detection
  84. ZTF23aaarlti/AT2023avj: VLA radio detection
  85. ZTF and LT Observations of AT2023avj, a Candidate Optical Afterglow
  86. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230125A
  87. Fermi GRB 230118A: Global MASTER-Net observations report
  88. Fermi GRB 230117A: Global MASTER-Net observations report
  89. GRB 230116C: Swift detection of a burst
  90. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-230109A
  91. IceCube-Cascade 230109A: Upper limits from a search for additional neutrino events in IceCube
  92. Fermi trigger No 695057654: Global MASTER-Net observations report
  93. Fermi Gamma-ray Burst Monitor trigger 694259491/230101411 is not a GRB
  94. Fermi GRB 221226A: Global MASTER-Net observations report
  95. IceCube Alert 221223.32: Global MASTER-Net observations report
  96. GRB 221216A: Nanshan/NEXT optical upper limits
  97. GRB 221215B: Fermi GBM Final Real-time Localization
  98. Fermi trigger No 692713692: Global MASTER-Net observations report
  99. IceCube-221210A: Upper limits from a search for additional neutrino events in IceCube
  100. Fermi GRB 221211A: Global MASTER-Net observations report

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