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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"

31632 results found.

  1. GRB 070724: optical observations
  2. GRB070724: Host galaxy redshift
  3. GRB 070724: P60 and Gemini Observations
  4. GRB 060814 - Keck host detection and redshift
  5. GRB 070724: Closer association with DSS source
  6. Swift/UVOT refined analysis of GRB070724
  7. GRB 070724: Swift-XRT Team refined analysis
  8. GRB 070724: Pre-Imaging Shows a Source in the XRT Error Circle
  9. Short-Hard GRB070714B: PROMPT Observations
  10. GRB 070724, Swift-BAT refined analysis of a short burst
  11. GRB 070721B: further observations and analysis
  12. GRB 070714B: Keck observations
  13. GRB 070721B: optical observations and proposed redshift
  14. Swift/UVOT observations of GRB070721B optical afterglow.
  15. GRB 070721B, Further Swift-BAT refined analysis
  16. Swift/UVOT Observations of GRB070721A
  17. GRB 070721B : Faulkes Telescope South observations
  18. GRB 070721B: Swift-XRT refined analysis
  19. GRB 070721A : Faulkes Telescope South optical limit
  20. GRB 070721A: Swift/XRT refined analysis
  21. GRB 070721B, Swift-BAT refined analysis
  22. GRB 070721A, Swift-BAT refined analysis
  23. GRB070721B: A bright UVOT candidate
  24. GRB 070721B: Swift detection of a burst
  25. GRB 070721: Swift detection of a possible burst
  26. GRB 070714B: Swift/BAT and Suzaku/WAM joint spectral analysis
  27. GRB 070714B : Suzaku WAM observation of the prompt emission
  28. GRB070714B: TNG NIR observations
  29. Erratum : Suzaku WAM observation of GRB 070704
  30. GRB 070714A: Swift/UVOT Upper limits
  31. GRB 070714B: Swift/UVOT Upper Limits
  32. GRB 070616: No Evidence for I Band Afterglow
  33. GRB 070714A: Swift XRT refined analysis
  34. GRB070714B: Swift-XRT refined analysis
  35. GRB 070707: Swift-XRT follow-up observations
  36. GRB 070714b ("Bastille"): Optical Pre-Imaging (Clarification)
  37. GRB 070714 ("Bastille"): Optical Pre-Imaging
  38. GRB 070714B, Swift-BAT refined analysis of the short hard burst
  39. GRB 070714A, Swift-BAT refined analysis
  40. GRB 070714 : Liverpool Telescope optical counterpart ?
  41. GRB 070704: RTT150 optical observations
  42. GRB 070704: Suzaku/WAM observation of the prompt emission
  43. Konus-Wind observation of GRB 070707
  44. GRB 070707: optical afterglow
  45. GRB 070707: object inside XRT error circle
  46. Swift/UVOT Observations of GRB070707
  47. Swift XRT observation of GRB 070707
  48. GRB 070707: VLT observations
  49. GRB 070429B: NIR Observations
  50. GRB070704: FAVOR optical observations
  51. GRB 070704 : Liverpool Telescope Observations
  52. GRB 070611: VLT observations
  53. VLA detection of GRB 070612A in C Band
  54. Konus-Wind observation of GRB 070626
  55. GRB 070704: Swift-XRT refined analysis
  56. Swift/UVOT Observations of GRB070704
  57. GRB 070704, Swift-BAT refined analysis
  58. GRB 070704: Correction to GCN Circ 6594
  59. GRB 070626: Suzaku/WAM observation of the prompt emission
  60. GRB 070628 Swift-UVOT Refined Analysis
  61. GRB 070628: NIR detection of afterglow
  62. GRB 070628, Swift-BAT refined analysis
  63. GRB 070628: TAROT La Silla observatory optical observations
  64. GRB 070628: Swift XRT refined analysis
  65. GRB 070628: Watcher Observations
  66. GRB 070612A: Allen Telescope Array Observations
  67. INTEGRAL burst GRB070615: X-ray continued observations
  68. GRB 070616 : WIDGET simultaneous optical observations
  69. GRB 070616: Suzaku/WAM observation of the prompt emission
  70. GRB 070612A: Second Epoch WSRT Radio Observations
  71. GRB070621: RTT150 optical observations
  72. GRB 070621: VLT optical observations
  73. GRB 070621: Swift/UVOT Upper Limits
  74. Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
  75. GRB 070621: Swift-BAT refined analysis
  76. GRB070621: Swift XRT refined analysis
  77. GRB 070621: Gemini South optical imaging
  78. Observations of GRB070612A at Calar Alto
  79. GRB 070621: NOT observations
  80. GRB070621: OPTIMA-Burst optical upper limit
  81. GRB 070621: Watcher Observations
  82. GRB 070621: ROTSE-III Prompt Optical Limits
  83. GMRT upper limit of GRB 070610/SWIFT J195509.6+261406 in 610 MHz
  84. GRB 070612A: TNG optical observations
  85. Swift/UVOT detection of GRB070616 optical afterglow.
  86. GRB070612A: Gemini Spectroscopic Redshift
  87. GRB 070612A: NOT observations
  88. GRB070616: Optical Observation by MITSuME Akeno
  89. GRB 070612B: Optical Observation by MITSuME Akeno
  90. GRB070616: Optical Observation by MITSuME Okayama
  91. GRB 070616, Swift-BAT further refined analysis
  92. GRB 070616: Swift XRT refined circular
  93. GRB 070612A: Possible WSRT Radio Detection
  94. Swift/UVOT observations of GRB070616
  95. GRB 070616: TLS observation
  96. Swift XRT observations of the INTEGRAL burst GRB070615: Possible
  97. GRB 070616, Swift-BAT partial refined analysis
  98. GRB 070612B: optical observations
  99. VLA upper limit on GRB 070610
  100. GRB 070615

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