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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"

4613 results found.

  1. GRB071020, optical upper limit
  2. GRB 071025: Swift-XRT Team refined analysis
  3. GRB 071025: Swift detection of a burst
  4. GRB 071021: Swift-XRT Team refined analysis
  5. GRB 071021: Swift detection of a burst
  6. GRB 071020: Swift-XRT refined analysis
  7. GRB 071013: 3rd TLS Epoch - constraints on variability
  8. GRB 071010B correction to GCN 6892 optical observations
  9. GRB 071010B: Super-LOTIS upper limit
  10. GRB 071010B optical photometry
  11. GRB 071010: Swift-XRT observation
  12. GRB 071010: Keck Observations of the Afterglow
  13. GRB 071010: TAROT La Silla observatory detection of the afterglow
  14. GRB 071003: Keck HIRES spectroscopy
  15. GRB 071001: Swift-XRT Team refined analysis
  16. Update on Swift Status
  17. GRB 070917: Confirmation of the X-ray afterglow
  18. GRB920925C: search for host galaxy
  19. GRB 070917: P60 Observations
  20. GRB 070917: Swift-XRT observations
  21. GRB 070917: Swift detection of a bright burst
  22. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  23. Konus-Wind observation of GRB 070824
  24. GRB 070824 - Combined SuperAGILE/IPN Localization
  25. GRB 070810A: ROTSE-III Refined Analysis
  26. GRB 070810B: Xinglong TNT optical Upper Limit
  27. A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
  28. GRB 070810: Swift-XRT Team Refined Analysis
  29. GRB 070809: Swift-XRT refined analysis
  30. GRB 070810: Swift/UVOT Optical Counterpart
  31. GRB 070810: Swift detection of a burst
  32. GRB 070809: ROTSE-III Optical Limits
  33. Swift trigger on 4U 1700-377 while star tracker loss-of-lock
  34. GRB 070802: Swift-XRT refined analysis
  35. GRB070729: Swift/UVOT upper limits
  36. GRB 070729: Swift-XRT refined analysis
  37. GRB 070724b: First Gamma Ray Burst Localization by SuperAGILE onboard
  38. GRB 070724: P60 and Gemini Observations
  39. GRB 070724: Swift-XRT Team refined analysis
  40. GRB 070721A: Swift/XRT refined analysis
  41. GRB 070714A: Swift XRT refined analysis
  42. GRB070714B: Swift-XRT refined analysis
  43. GRB 070704: Swift-XRT refined analysis
  44. GRB 070626: IPN localization and Konus spectrum of a bright long burst
  45. GRB070621: RTT150 optical observations
  46. GRB 070621: VLT optical observations
  47. Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
  48. GRB070621: Swift XRT refined analysis
  49. GRB 070621: Gemini South optical imaging
  50. GRB 070621: UVOT-enhanced XRT position
  51. GRB 070621: NOT observations
  52. GRB 070621: ROTSE-III Prompt Optical Limits
  53. Swift XRT observations of the INTEGRAL burst GRB070615: Possible
  54. SWIFT J195509.6+261406 (GRB 070610): further observations
  55. GRB 070612A: continued SARA observations
  56. GRB 070612B: SARA upper limit
  57. GRB 070612B: KAIT limits
  58. GRB 070610: TAROT Calern observatory optical observations
  59. GRB 070611: Swift-XRT refined analysis
  60. GRB 070529: Swift-XRT refined analysis
  61. GRB 070521: Swift-XRT refined analysis
  62. GRB 070520A: Subaru Observations
  63. GRB 070520B: Swift-XRT refined analysis
  64. GRB 070521: optical limit by Pi of the Sky
  65. GRB 070521: TAROT La Silla observatory optical observations
  66. GRB 070520A: Swift-XRT refined analysis
  67. GRB 070518: Swift-XRT refined analysis
  68. GRB070517: Swift-XRT Refined Analysis
  69. GRB070509: Swift-XRT Refined Analysis
  70. Swift-BAT trigger 278809 is not a GRB
  71. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  72. GRB070506: Swift XRT refined analysis
  73. GRB 070506: Swift detection of a burst with optical afterglow
  74. GRB 070429A: optical observations
  75. Swift/UVOT observations of GRB070429A
  76. GRB 070429A: Swift XRT refined analysis
  77. GRB 070429A: optical and NIR observations
  78. GRB 070429B: Swift XRT refined analysis
  79. GRB 070429: Swift detection of a burst
  80. GRB070419A, optical observation
  81. GRB 070418: Optical and IR observations with KANATA
  82. GRB 070411: Swift-XRT refined analysis
  83. GRB 070412: Gemini/GMOS afterglow candidate
  84. GRB 070412: NOT observations
  85. Suzaku ToO observation of SGR 1806-20
  86. IPN triangulation of GRB070402
  87. long burst from SGR 1806-20 detected on March 26
  88. GRB 070328: Swift/XRT Refined Analysis
  89. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  90. GRB 070311: Swift-XRT refined analysis
  91. GRB 070306, optical observation
  92. GRB 070306: ART-3 early optical and near infrared constraints
  93. GRB 070306: XRT Team Refined Analysis
  94. GRB 920925C: optical afterglow candidate
  95. VLA observation of GRB 070220
  96. GRB 070224: WHT K-band imaging
  97. GRB 070224: MASTER-Net refind analysis
  98. GRB 070224: MASTER observations
  99. GRB 070220: MITSuME Okayama Optical Observation
  100. GRB 070220: Swift-XRT Refined Analysis

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