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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. Possible radio detection of GRB 071021 with the VLA
  2. GRB 071021: correction to GCNC 6968
  3. GRB 071021: optical and NIR observations
  4. GRB 071021: Swift-XRT Team refined analysis
  5. GRB 071021: Faulkes Telescope South optical candidate
  6. GRB 071021: Swift detection of a burst
  7. GRB071010b: optical observations
  8. GRB 071010A: Continued Keck Imaging
  9. GRB 071010B: Bright OT confirmed with TLS
  10. GRB 071010, Swift-BAT refined analysis
  11. Konus-Wind observation of GRB 071006
  12. GRB 071010 REM NIR observations
  13. GRB 071010: Swift detection of a burst
  14. GRB 070810B: further XRT analysis
  15. GRB 071003: OA power-law decay indices from KAIT
  16. GRB 071003: KAIT optical afterglow observations
  17. GRB 070911, SMARTS optical/IR afterglow observations
  18. INTEGRAL ToO observations of SGR1806-20
  19. GRB 070913: Swift-BAT refined analysis
  20. GRB 070731, Swift-BAT refined analysis
  21. VLA upper limit on short hard burst GRB 070714B
  22. Konus-Wind observation of GRB 070724B
  23. GRB 070704, Swift-BAT refined analysis
  24. GRB 070628: Swift detection of a possible burst
  25. GRB 070612A: Allen Telescope Array Observations
  26. GRB 070612A: Super-LOTIS observations
  27. GRB 070611: Watcher Observations
  28. GRB 070612B: KAIT limits
  29. GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
  30. GRB 070521: optical limit by Pi of the Sky
  31. GRB 070506, Swift-BAT Refined Analysis
  32. GRB 070506: Swift detection of a burst with optical afterglow
  33. GRB 070429: Swift detection of a burst
  34. GRB 070427: Swift detection of a burst
  35. GRB 070420 Swift-BAT Refined Analysis
  36. GRB070419A, optical observation
  37. GRB 070412: Optical observations at Crni Vrh
  38. GRB 070411: Tautenburg RRM Afterglow Confirmation
  39. GRB 070406: Xinglong TNT optical Upper Limit
  40. GRB 070318: Swift detection of a burst with an optical afterglow
  41. IPN localization of very bright long hard GRB 070207
  42. RHESSI Spectrum of GRB070125
  43. Konus-Wind observation of GRB 061222A
  44. GRB 061222b, SMARTS optical/IR afterglow observations
  45. GRB 061217: ROTSE-III Optical Limits
  46. GRB 061121: Second Epoch ATCA Radio Observations
  47. GRB 061126: Early Detection of the IR Afterglow
  48. GRB 061121: MDM Continued Monitoring
  49. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  50. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  51. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  52. GRB 060928: Swift observations
  53. GRB 060923A: Keck and Gemini Observations
  54. GRB 060923, Swift-BAT refined analysis
  55. GRB 060908: Swift/UVOT Observations
  56. GRB 060906: observations with FRAM
  57. GRB 060904B: RTT150 optical observations
  58. GRB060814: Break in the XRT light curve
  59. GRB 060805B: Swift/UVOT Upper Limits
  60. GRB060719: prompt NIR observations with REM
  61. GRB050326: Host Galaxy Candidates
  62. GRB050124: Possible Host Galaxy
  63. GRB050223: Host Galaxy
  64. GRB 060522: PROMPT Optical Limits
  65. GRB 060507: Swift-BAT Refined Analysis
  66. GRB 060502: Swift detection of a burst with an optical counterpart
  67. GRB060428B, optical observation
  68. GRB 060428A: Refined analysis of the Swift-BAT burst
  69. GRB 060421: TTT Observations
  70. GRB060413: Swift/UVOT upper limits
  71. GRB 060413: Swift detection of a burst
  72. SGR 1900+14: BAT observations
  73. HETE Trigger 4043: ROTSE-III Optical Limits
  74. H4043, an unusual high-energy transient observed by HETE
  75. GRB 060322: Confirmation of Swift XRT afterglow
  76. GRB 060322: Swift XRT afterglow candidate
  77. GRB 060319: Swift detection of a burst
  78. Bright short hard GRB 060303: IPN localization and Konus spectrum
  79. GRB 060218/SN 2006aj: RBO optical observations
  80. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  81. GRB 050826: Optical Afterglow and Host Galaxy
  82. GRB 060211: Swift detection of a long burst
  83. GRB 060130: PROMPT Observations
  84. GRB 060124: Swift-BAT detection of a burst
  85. GRB 060116: IR Candidate Afterglow
  86. GRB 060115: OT photometry with MITSuME
  87. Swift Trigger 172767 is not a GRB
  88. GRB 051105b: ART optical limits
  89. SGR 1806-20: continued moderate activity seen with INTEGRAL
  90. GRB 051022 Chandra Observations scheduled
  91. GRB051021b: Magellan IR Imaging
  92. GRB051008: optical candidate
  93. GRB051008: optical observation
  94. GRB051008: Radio Observation
  95. GRB 051008: Swift XRT position
  96. GRB 051008: Swift UVOT Candidate
  97. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  98. GRB 051001: Swift Detection of a Burst
  99. GRB050922B: Swift UVOT early upper limits.
  100. GRB 050922B: optical limit

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