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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"

4953 results found.

  1. GRB 120302A: GROND detection of an afterglow candidate
  2. GRB 120227A: RAPTOR Limit During the Gamma-Ray Emitting Interval
  3. Swift Trigger 516027 is CC Eri
  4. GRB 120219A: Swift detection of a burst
  5. Fermi GBM detection of an SGR-like burst
  6. GRB 120212A: Fermi GBM observation
  7. GRB 120212A: Swift-XRT observations
  8. GRB 120212A: Faulkes Telescope South afterglow candidate
  9. GRB 120212A: Swift detection of a burst
  10. IPN Triangulation of GRB 120129A (long/intense)
  11. GRB 120127A: MAXI/GSC detection of a probable GRB
  12. GRB 120119A: optical upper limit
  13. GRB 120121A: Swift detection of a burst
  14. GRB 120119A: optical observations
  15. GRB 120119A: Swift/UVOT Observations
  16. GRB 120119A: optical observations
  17. GRB 120119A: Swift detection of a burst with an optical counterpart
  18. XRF 120118A: Optical candidate
  19. AXP 4U 1042+61: Mondy optical observations
  20. GRB 120114A found in ground analysis of BAT data
  21. AXP 4U 0142+61: Swift-BAT refined analysis (trigger 511611)
  22. Swift detection of an SGR burst from AXP 4U 0142+61
  23. GRB 120107A: Suzaku WAM observation of the prompt emission
  24. GRB 120107A: Fermi GBM observation
  25. Konus-Wind observation of GRB 120107A
  26. IPN Triangulation of GRB 120107A
  27. GBM trigger 347620337 (GRB 120107A?) : High-energy photon emission in Fermi/LAT data
  28. GRB 120106A: Swift detection of a burst
  29. GRB 111228A: Swift detection of a burst with an optical counterpart
  30. GRB 111205A: optical observations
  31. GRB111225A: MITSuME Okayama optical upper limits
  32. GRB 111225A: Swift detection of a burst with an optical counterpart
  33. GRB 111210A: optical upper limit of Mt. Terskol observatory
  34. GRB 111211A: optical ovservations at Mt. Terskol observatory
  35. GRB 111215A: Swift detection of a burst
  36. GRB 111212A: Swift detection of a burst
  37. GRB 111210A: Gemini-North candidate counterpart
  38. GRB 111210A: Enhanced Swift-XRT position
  39. GRB 111210A: Swift detection of a burst
  40. GRB 111209A: IRTF NIR Imaging/Spectroscopy
  41. GRB 111209A optical limit by "Pi of the Sky"
  42. GRB111209A : planned XMM-Newton observation
  43. GRB 111123A: Swift detection of a burst
  44. GRB 111121A: Swift detection of a short hard burst
  45. GRB 111109A: Swift/UVOT Photometry
  46. GRB 111029A: RAPTOR Limits During the Gamma-ray Emitting Interval
  47. GRB 111029A: KAIT optical limits
  48. GRB 111029A: Faulkes Telescope North observations
  49. GRB 111029A: optical upper limit
  50. GRB 111029A: ROTSE-III Optical Limits
  51. GRB 111029A: Swift detection of a burst
  52. GRB 111022B: EVLA observations
  53. GRB 111022B: MITSuME Akeno Optical upper limits
  54. GRB 111020A: BOOTES-3 Optical Upper Limit.
  55. IPN Triangulation of GRB 111016B (long duration, intense)
  56. GRB 111008A : miniTAO/ANIR NIR observations
  57. Fermi GBM triggers 110923481, 110924391 and 110925200 are not GRBs
  58. GRB 110924A: Swift detection of a possible burst
  59. GCN for GRB 110921B
  60. GRB110918A: Lick Observations
  61. GRB 110921A: MASTER-Net early limit
  62. MAXI/GSC detection of a short soft X-ray transient
  63. GRB 110915A: Deep Gemini-South i/z-band imaging
  64. GRB 110915A: MITSuME Okayama and Ishigakijima Optical upper limits
  65. GRB 110915A: GMG optical upper limit
  66. GRB 110915A: MASTER-Net early limit
  67. GRB 110731A: SAO RAS and Terskol observations
  68. GRB 110906A(?): Burst detection (unconfirmed) from Swift-BAT slew data
  69. IPN triangulation of GRB 110820B (very long duration, extremely intense)
  70. GRB 110818A: Optical afterglow and redshift from VLT/X-shooter
  71. GRB 110818A: Swift-XRT refined Analysis
  72. GRB 110815A : Suzaku WAM observation of the prompt emission
  73. Konus-Wind observation of GRB 110815A
  74. GRB 110808A: VLT/X-shooter spectroscopy
  75. GRB 110731A : Suzaku WAM observation of the prompt emission
  76. AXP 4U 0142+61: Fermi GBM detection
  77. GRB 110731A Gemini-N redshift
  78. Konus-Wind observation of GRB 110731A
  79. GRB 110731A: Fermi GBM observation
  80. GRB 110731A: Swift detection of a burst with an optical counterpart
  81. AXP 4U 0142+61: Swift-BAT refined analysis
  82. Swift detection of a SGR-like burst from the AXP 4U 0142+61
  83. IPN triangulation of GRB 110721A
  84. GRB 110719A: Swift detection of a burst
  85. IPN triangulation of GRB 110708B (long duration, extremely intense)
  86. GRB 110709A: Fermi GBM observation
  87. GRB 110709A: MASTER-NET optical observations
  88. Swift Trigger 456659 is probably not astrophysical
  89. Swift J185003.2-005627: NIR Observation
  90. GRB 110625A: Swift detection of a burst
  91. SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
  92. GRB 110428A: Fermi-GBM observation
  93. GRB 110428A: Suzaku WAM observation of the prompt emission
  94. Konus-Wind observation of GRB 110428A
  95. GRB 110426A: MAXI/GSC detection of a GRB
  96. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  97. GRB 110414A: Swift detection of a burst
  98. GRB 110411A: PAIRITEL NIR Upper Limits
  99. GRB 110411A: MASTER prompt and follow-up optical limits
  100. GRB 110411A: Swift detection of a burst

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