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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"

21986 results found.

  1. GRB 230812B: Koshka Zeiss-1000 optical observations
  2. GRB 230812B: Leavitt Observatory optical observations
  3. GRB 230812B : optical observations from Observatoire de Haute-Provence
  4. GRB 230812B: Bassano Bresciano Observatory optical observations
  5. GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
  6. GRB 230812B: OASDG optical observations
  7. GRB 230812B: AbAO optical observations
  8. GRB 230812B: Montarrenti Observatory optical observations
  9. GRB 230812B: SAO RAS optical observations
  10. GRB 230812B: GMG - GRANDMA observations
  11. GRB 230812B: Swift-XRT afterglow detection
  12. GRB 230812: Swift/UVOT Detection
  13. GOTO confirmation and possible host galaxy of GRB230812B optical afterglow
  14. GRB 230812B: KAIT Optical Afterglow Candidate
  15. LAT GRB230812.79: Global MASTER-Net observations report
  16. Fermi GRB 230812B: Global MASTER-Net observations report
  17. GRB 230812B: Tiled Swift observations
  18. ZTF23aaoohpy/AT2023lcr: JWST spectroscopy confirmation of an associated type Ic-BL supernova
  19. Fermi trigger No 713525317: Global MASTER-Net observations report
  20. GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
  21. GRB 230808A: Swift/BAT-GUANO detection of a burst
  22. Fermi trigger No 713136868: Global MASTER-Net observations report
  23. Fermi trigger No 713205976: Global MASTER-Net observations report
  24. ZTF23aaoohpy/AT2023lcr: JWST observations consistent with the presence of a supernova
  25. transient SPT-SVJ025406.5-702837: ATCA follow-up observations
  26. Fermi GRB 230807A: Global MASTER-Net observations report
  27. Fermi trigger No 713134237: Global MASTER-Net observations report
  28. LIGO/Virgo/KAGRA S230805x: Upper limits from Swift/BAT-GUANO
  29. GRB 230805B : OHP/T193 optical upper limit
  30. GRB 230805B: Swift/UVOT Upper Limits
  31. Fermi trigger No 712991593: Global MASTER-Net observations report
  32. GRB 230805B: Bassano Bresciano observatory upper limit
  33. Fermi trigger No 712987357: Global MASTER-Net observations report
  34. GRB 230805B: NOT optical afterglow confirmation
  35. Fermi GRB 230805A: Global MASTER-Net observations report
  36. GRB 230805B: SAO RAS optical observations
  37. Fermi trigger No 712927418: Global MASTER-Net observations report
  38. Swift GRB 230805B: Global MASTER-Net observations report
  39. Fermi trigger No 712798043: Global MASTER-Net observations report
  40. GRB 230802A: Swift/UVOT Upper Limits
  41. Fermi trigger No 712718833: Global MASTER-Net observations report
  42. Fermi trigger No 712713532: Global MASTER-Net observations report
  43. Fermi trigger No 712651827: Global MASTER-Net observations report
  44. Swift GRB 230802A: Global MASTER-Net observations report
  45. LIGO/Virgo/KAGRA S230802aq: Upper limits from Fermi-GBM Observations
  46. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  47. IceCube-230724A: JCMT/SCUBA-2 submm observations
  48. IceCube-230707A: JCMT/SCUBA-2 submm observations
  49. LIGO/Virgo/KAGRA S230731an: Upper limits from Swift/BAT-GUANO
  50. LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
  51. GRB 230723A: Detection of candidate millimeter-band radiation by SPT-3G
  52. Fermi trigger No 712390645: Global MASTER-Net observations report
  53. Fermi-LAT gamma-ray observations of IceCube-230727A
  54. Fermi trigger No 712306969: Global MASTER-Net observations report
  55. IceCube-230727A: No candidates from the Zwicky Transient Facility
  56. GRB 230728A: Swift/UVOT Upper Limits
  57. GRB 230728A: NOT optical observations and possible host galaxy
  58. IceCube-230724A: No counterparts from the Zwicky Transient Facility
  59. Swift GRB230728.12: Global MASTER-Net observations report
  60. GRB 230727A: Swift/BAT-GUANO detection of a burst
  61. Fermi-LAT gamma-ray observations of IceCube-230725A
  62. Fermi-LAT gamma-ray observations of IceCube-230724A
  63. Fermi trigger No 712143685: Global MASTER-Net observations report
  64. Integral GRB230726.26: Global MASTER-Net observations report
  65. GRB 230723B: Further CAHA observations and host galaxy detection
  66. GRB 230723B: ATCA rapid radio follow-up
  67. Integral GRB230725.99: Global MASTER-Net observations report
  68. IceCube Alert 230725.90: Global MASTER-Net observations report
  69. GRB 230723B: GAD Observatory, La Spezia, Italy upper limit
  70. GRB 230723B: Leavitt Observatory upper limit
  71. GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
  72. GRB 230723B: Montarrenti Observatory upper limit
  73. GRB 230723B: Optical afterglow candidate from CAHA
  74. GRB 230723B: Bassano Bresciano Observatory upper limit
  75. GRB 230723B: non-detections from Observatoire de Haute-Provence
  76. IceCube Alert 230724.08: Global MASTER-Net observations report
  77. Fermi trigger No 711853834: Global MASTER-Net observations report
  78. Fermi trigger No 711805358: Global MASTER-Net observations report
  79. GRB 230723B: Optical limit from CAHA
  80. GRB 230723B: Swift/UVOT Upper Limits
  81. Swift GRB 230723B: Global MASTER-Net observations report
  82. GRB 230723B: Swift-XRT observations
  83. Fermi GRB 230723A: Global MASTER-Net observations report
  84. Swift GRB230720.30: Global MASTER-Net observations report
  85. Fermi trigger No 711088412: Global MASTER-Net observations report
  86. Fermi GRB 230713A: Global MASTER-Net observations report
  87. GRB 230709C: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  88. IceCube-230708A: Upper limits from Swift/BAT-GUANO
  89. Fermi trigger No 710741042: Global MASTER-Net observations report
  90. IceCube-230707A: No candidates detected by Swift-XRT
  91. IceCube-230707A: No candidates from the Zwicky Transient Facility
  92. Fermi-LAT gamma-ray observations of IceCube-230708A
  93. Fermi-LAT gamma-ray observations of IceCube-230707B
  94. Fermi-LAT gamma-ray observations of IceCube-230707A
  95. GRB 230707B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  96. GRB 230707A: Swift-XRT observations
  97. IceCube Alert 230708.35: Global MASTER-Net observations report
  98. IceCube Alert 230707.71: Global MASTER-Net observations report
  99. GRB 230707A: Swift ToO observations
  100. GRB 230707A: Swift/BAT-GUANO arcminute localization of a burst

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