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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"

2676 results found.

  1. GRB050922B: Swift-BAT detection of a weak long burst
  2. Swift-BAT trigger 155764 is not a GRB
  3. Swift-BAT trigger 155764 is probably not a GRB
  4. GRB 050915: Swift detection of a GRB
  5. GRB050908: VLT R-band decay index.
  6. GRB 050908: Swift detection of a burst
  7. GRB050904: Optical Observations
  8. GRB 050826: Optical Candidate
  9. GRB050824: MASTER:OT decay
  10. GRB 050820: Swift detection of a GRB
  11. GRB050814: P60 Optical Afterglow Candidate
  12. Retraction of Swift Trigger 149131 (GRB 050805B)
  13. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  14. GRB 050802 : Lulin Optical follow-up observation
  15. GCN 050801: early Swift XRT analysis results
  16. GRB 050730: Swift XRT afterglow observations
  17. GRB050721A: Swift-BAT detection of a weak burst
  18. GRB 050626: Swift XRT observations
  19. GRB 050701: Swift XRT afterglow position
  20. Swift trigger 143708 is really GRB 050701
  21. GRB050603: Fading Afterglow observed by Swift UVOT
  22. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  23. GRB050502b: Early Observation
  24. GRB 050509a: Swift-BAT refined analysis
  25. GRB 050509A: Optical observations
  26. GRB 050509a: Swift XRT Position
  27. GRB 050502a: Swift XRT Upper Limit
  28. GRB 050502a: Optical Observations
  29. GRB 050504: Swift XRT position
  30. GRB050502A: Optical Observations
  31. GRB 050502: Confirmed variability of the afterglow candidate +
  32. GRB050502 - Correction on the Optical Candidate from the Liverpool
  33. GRB050502 - Optical Candidate from the Liverpool Telescope
  34. GRB 050502: ROTSE-III Detection of Possible Counterpart
  35. GRB 050422: Swift-BAT refined analysis
  36. Swift Detection of GRB050421
  37. GRB 050416: Radio observations
  38. GRB 050412: Swift XRT Position
  39. GRB 050408: Optical limit at 20 min after the burst
  40. Swift-BAT detection of GRB 050401
  41. GRB 050401: Prompt XRT position
  42. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  43. GRB050315: Radio afterglow
  44. GRB 050315: Optical afterglow identification
  45. GRB 050315: Swift XRT Position
  46. Swift-BAT detection of GRB 050315
  47. GRB050309: CONCAM pre-trigger and trigger coincident optical
  48. Swift trigger 107518: optical observation
  49. GRB 050306: TAROT optical observations
  50. GRB 050215b: XRT confirmation of IR afterglow candidate
  51. GRB 050215b: Swift XRT Source Variability
  52. GRB050128,optical observations
  53. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  54. GRB050126: Updated Swift XRT Position
  55. GRB050126: MASTER optical limit for KECK OT
  56. GRB050126: MASTER optical observations
  57. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  58. GRB 050126: Prompt XRT detection and localization
  59. GRB 050124, SMARTS optical/IR observations
  60. GRB 050124: NIR Candidates from Keck/NIRC
  61. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  62. GRB041219; RXTE ASM Observations
  63. GRB 041219 ,optical observation
  64. Swift-BAT detection of the bright long burst GRB041219
  65. GRB041217: The First GRB Located On-Board Swift
  66. GRB 041211: Infrared Observations
  67. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  68. Triangulation of short GRB 041116 (large error box)
  69. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  70. GRB040924: Optical afterglow properties
  71. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  72. GRB040912 : Kiso Optical follow-up observation
  73. GRB040823,optical observation
  74. GRB 040812: Optical counterparts of CXO sources
  75. CXO observation of GRB 040812
  76. GRB 040812: a long GRB detected by INTEGRAL
  77. IPN Summary of SGR1806-20 Activity in 2004
  78. Activivty of SGR 1806-20
  79. IPN triangulation of GRB040228 (H3066, H3067)
  80. XMM-Newton Images of GRB 040223
  81. IPN triangulation of GRB031027 (small error box)
  82. Lulin optical follow-up observations of GRB031026
  83. IPN triangulation of GRB030926 (short/hard; large error box)
  84. IPN triangulation of GRB030903 (large error box)
  85. IPN triangulation of GRB030801 (large error box)
  86. XRF030723(=H2777): Chandra Observations
  87. XRF030723: Palomar observations and proposed counterpart
  88. XRF 030723, optical observations
  89. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  90. IPN triangulation of GRB030715 (two large error boxes)
  91. GRB 021206, Radio afterglow candidate
  92. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  93. GRB 030329 Optical Observations
  94. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  95. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  96. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  97. IPN triangulation of GRB030422 (two large error boxes)
  98. ROTSE-III prompt optical detections of GRB 030418
  99. GRB030329: Kiso B and R band observations
  100. GRB 030329: SARA Optical Observations

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