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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

28084 results found.

  1. GRB 150318A: Swift detection of a burst
  2. GRB 150317A: Swift/UVOT Upper Limits
  3. GRB 150317A: Swift-XRT refined Analysis
  4. GRB 150317A: Swift-BAT refined analysis
  5. GRB 150317A: RATIR Optical Afterglow Detection
  6. GRB 150317A: Enhanced Swift-XRT position
  7. GRB 150317A: NOT optical observations
  8. GRB 150317A: Swift detection of a burst
  9. GRB 150314A: Early RAPTOR Detection
  10. GRB 150220A, the review of the sky area in plate archives
  11. GRB 150314A: NOT further optical observations
  12. GRB 150314A: Swift-XRT refined Analysis
  13. GRB 150314A: Redshift from OSIRIS/GTC
  14. GRB 150314A: NOT optical observations
  15. GRB 150314A Swift-BAT refined analysis
  16. GRB 150314A: Swift/UVOT Detection
  17. GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow
  18. GRB 150314A: Enhanced Swift-XRT position
  19. GRB 150314A: Swift detection of a bright burst
  20. GRB 150313A: MAXI/GSC detection
  21. GRB 150309A: AAO optic upper limit
  22. GRB 150311A: MAXI/GSC possible afterglow detection
  23. GRB 150222A: CrAO optical observation
  24. GRB 150309A: CrAO optic upper limit
  25. GRB 150309A: ISON-Kislovodsk optic upper limit
  26. GRB 150309A: Swift-BAT refined analysis
  27. GRB 150309A: Fermi GBM detection
  28. GRB150309A: Optical observations at Crni Vrh
  29. GRB 150309A: Swift/UVOT Upper Limits
  30. GRB 150309A: MASTER prompt optical observation
  31. GRB 150309A: Swift-XRT refined Analysis
  32. GRB 150309A: Enhanced Swift-XRT position
  33. GRB 150309A: BOOTES-1 and -2 upper limit
  34. GRB 150309A: Swift detection of a burst
  35. GRB 150305A: a long GRB detected by INTEGRAL
  36. Swift J0045.2+4151: analysis of XMM-Newton archival data
  37. Further UVOT Observations of Swift J0045.2+4151
  38. Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
  39. BAT trigger 633105 (GRB 150301C): NOT r-band upper limit
  40. GRB 150302A: BOOTES-2/TELMA upper limit
  41. Trigger 633105 (aka GRB150301C): Swift/UVOT Observations of XRT Counterpart
  42. GRB 150302A: Mondy optical upper limit
  43. GRB 150302A, Swift-BAT refined analysis
  44. GRB 150302A: Swift/UVOT Upper Limits
  45. GRB 150302A: MITSuME Okayama upper limits
  46. GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
  47. GRB 150302A: Swift-XRT refined Analysis
  48. GRB 150302A: Enhanced Swift-XRT position
  49. GRB 150301B: Swift-XRT refined Analysis
  50. GRB 150220A: further Swift-XRT observations
  51. GRB 150301B: Swift/UVOT Observations
  52. GRB 150301B: LCOGT-Sutherland observations
  53. GRB 150302A: NOT afterglow candidate
  54. GRB 150302A: Swift detection of a burst
  55. GRB 150301B: Fermi GBM detection
  56. GRB 150301B: Swift-BAT refined analysis
  57. GRB 150301B: GROND afterglow observations
  58. GRB 150301A: Swift/UVOT Upper Limits
  59. GRB 150301B: Enhanced Swift-XRT position
  60. GRB 150301A: Swift-BAT refined analysis
  61. GRB 150301B: MASTER early OT detection
  62. GRB 150301A: Swift-XRT refined Analysis
  63. GRB 150301C : (Swift trigger 633105) Swift observations
  64. GRB 150301B: Swift detection of a burst with an optical afterglow
  65. GRB 150301A: GROND Observations
  66. Trigger 633105 is likely not a GRB
  67. GRB 150301A: Swift detection of a short burst or new SGR
  68. Swift-BAT refined analysis of magnetar 4U 0142+61 (Trigger 632888)
  69. Fermi GBM Observations of Magnetar 4U 0142+61
  70. Trigger 632888: Swift detection of the magnetar 4U 0142+61
  71. GRB 150222A: Further GROND Observations
  72. GRB 150220A: Swift-XRT observations
  73. GRB 150222A: I-band observations from OSN
  74. GRB 150222A: Swift/UVOT Upper Limits
  75. GRB 150222A: Swift-XRT refined Analysis
  76. GRB 150222B: MAXI/GSC detection
  77. Fermi GBM Observations of SGR 1935+2154
  78. GRB 150222A: GROND optical afterglow candidate
  79. GRB 150222A: Enhanced Swift-XRT position
  80. GRB 150222A: TNG optical observations
  81. GRB 150222A: Swift-BAT refined analysis
  82. SGR 1935+2154: Swift-BAT refined analysis
  83. GRB 150222A: Mondy optical observations
  84. GRB 150222A: Zadko observatory - Gingin optical observations
  85. GRB 150222A: Swift detection of a burst
  86. Swift detection of an outburst from SGR 1935+2154
  87. GRB 150213B, the review of the sky area in plate archives
  88. GRB 150219A: Swift-XRT afterglow detection
  89. Trigger 631747: Swift detection of 4U 0614+09
  90. GRB 150213B: AAO photometry
  91. GRB 150219A: A long GRB detected by INTEGRAL
  92. GRB 150213B: Enhanced Swift-XRT position
  93. GRB 150212A, the review of the sky area in plate archives
  94. GRB 150213B: Swift/UVOT Detection
  95. GRB 150213B: Swift-BAT refined analysis
  96. GRB 150213B: RATIR Optical and NIR Observations
  97. GRB 150213B: Swift-XRT refined Analysis
  98. GRB 150213B: AAO optical observations
  99. GRB 150213B: optical detection from the NOT
  100. GRB 150212A: Swift/UVOT Observations

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