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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"

41674 results found.

  1. GRB 140928A: GROND Afterglow Candidate
  2. GRB 140928A: Swift-XRT observations
  3. GRB 140928A: Fermi-LAT detection
  4. GRB 140927A: Swift-UVOT analysis
  5. GRB 140927A: Swift-BAT refined analysis
  6. GRB 140927A: Swift-XRT refined Analysis
  7. GRB 140927A: Swift detection of a burst
  8. Swift Trigger 613581 is not an astrophysical event
  9. GRB 140919A, Swift-BAT refined analysis
  10. GRB 140919A: Swift-XRT refined Analysis
  11. GRB 140919A: Swift/UVOT Detection
  12. GRB 140919A: GROND afterglow candidate
  13. GRB 140919A: Fermi GBM observation
  14. GRB 140919A: Swift/UVOT observations
  15. GRB 140919A: Swift detection of a burst
  16. GRB 140916B: LOT and iPTF follow-up of optical afterglow candidates
  17. Swift detection of outburst from 4U 1700+24
  18. GRB 140916A: Swift/UVOT Upper Limits
  19. GRB 140916A: Swift-BAT refined analysis
  20. GRB 140916A: UKIRT J-band observations
  21. GRB 140916A: Swift-XRT refined Analysis
  22. GRB 140916A: MITSuME Okayama upper limits
  23. GRB 140916B: iPTF Optical Observations
  24. GRB 140916A: FTS observations
  25. GRB 140916A: Swift detection of a burst
  26. GRB 140907A: Continued DCT Observations
  27. Fermi GBM trigger 140913075 is not a GRB
  28. GRB 140909A: Confirmation of the Swift-XRT afterglow
  29. Possible radio detection of GRB 140903A with the GMRT
  30. GRB 140907A: Mondy optical observations
  31. GRB 140903A: Chandra detection of the afterglow
  32. GRB 140909A: Swift/UVOT Upper Limits
  33. GRB 140909A: Swift-XRT observations
  34. GRB 140907A: 1.23m CAHA optical observations
  35. GRB 140907A: TShAO observations
  36. GRB 140909A: Swift detection of a GRB
  37. Konus-Wind observation of GRB 140906C
  38. GRB 140907A: MASTER optical observations
  39. Refined IPN Triangulation of GRB 140906C
  40. GRB 140907A: Nishi-Harima NIR Observations
  41. GRB 140907A: MITSuME Akeno Optical Observation
  42. GRB 140907A: Discovery Channel Telescope observations
  43. IPN Triangulation of GRB 140906C (short/hard)
  44. GRB 140907A: T100 observations
  45. GRB 140907A: Swift-BAT refined analysis
  46. GRB 140907A: Fermi GBM Detection
  47. GRB 140907A: redshift from the 10.4m GTC telescope
  48. GRB 140907A: Swift-XRT refined Analysis
  49. GRB 140907A: MITSuME Ishigakijima Optical Observation
  50. GRB140907A: MITSuME Okayama Optical Observation
  51. GRB 140907A : Virtual Telescope optical observations
  52. GRB140907A: Swift UVOT detection
  53. GRB 140906B: Fermi GBM Detection of a Long GRB
  54. GRB 140907A : Optical observations from Nanshan
  55. GRB 140907A: Swift detection of a burst with an optical counterpart
  56. GRB 140906A - Fermi GBM Detection
  57. GRB 140906A: iPTF optical transient candidates
  58. GRB 140903A: Confirmation of Optical Fading from Discovery Channel Telescope
  59. GRB 140903A: Possible optical variability
  60. GRB 140903A: NOT optical and NIR observations
  61. GRB 140901B: Swift XRT observation
  62. GRB 140903A: FTN observations
  63. GRB 140818B: TShAO optical upper limit
  64. GRB 140903A: ISON-Kislovodsk observations
  65. GRB 140903A: MAXI/GSC upper limit
  66. GRB 140903A: 6 GHz VLA detection
  67. GRB 140903A: Pan STARRS images of the field
  68. GRB 140901B: Fermi GBM detection
  69. GRB 140903A: tentative spectroscopic redshift
  70. GRB 140901B found in ground analysis of BAT data
  71. GRB 140903A: Swift/UVOT Upper Limits
  72. GRB 140903A: Swift-BAT Spectral lag analysis
  73. GRB 140903A: P60 Optical Observations
  74. GRB140903A: Discovery Channel Telescope Optical Detection
  75. GRB 140903A: Swift-BAT refined analysis
  76. GRB 140903A: Swift-XRT refined Analysis
  77. GRB 140903A: Coincident galaxy cluster in archival images
  78. GRB 140903A: Preliminary Swift/XRT localization
  79. GRB 140903A: Swift detection of a possible burst
  80. GRB 140901A: Fermi GBM detection
  81. IPN Triangulation of GRB 140901A (short/hard/very intense)
  82. GRB 140831A: iPTF observations of a possible short burst detected by Fermi GBM
  83. GRB 140829A: Fermi GBM Detection
  84. GRB 140829A: iPTF optical observations
  85. GRB140818B, the review of the sky area in plate archives
  86. GRB 140828A, Swift-BAT refined analysis
  87. Konus-Wind observation of GRB 140825A
  88. GRB 140828A: Fermi GBM observation
  89. Swift Mission Operations Center Fully Operational
  90. IPN Triangulation of GRB 140825A (very intense/long)
  91. GRB 140828A: Swift detection of a burst
  92. IPN Triangulation of GRB 140824B
  93. Swift Burst Response Reenabled
  94. GRB 140818B: TLS observations
  95. GRB 140824A: optical upper limit in CrAO
  96. GRB 140824B: Swift observations
  97. Fermi TRIGGER_NUM 430645968: MASTER OT inside error box
  98. Swift Mission Operations Center Moving Tomorrow
  99. GRB 140824B: Fermi GBM Detection
  100. GRB 140821A: Fermi GBM Detection

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