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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"

15687 results found.

  1. GRB 060515: Super-LOTIS Observations
  2. GRB 060515: TAROT optical observation
  3. GRB 060515: ROTSE-III Optical Limits
  4. VLT optical spectroscopy of GRB 060512
  5. Swift/UVOT observations of GRB060512.
  6. GRB060512: Swift XRT Team refined analysis
  7. GRB 060512: 1.54m Kuiper Observations
  8. GRB 060512: optical decay
  9. GRB 060512: REM NIR observations
  10. GRB 060512: Swift detection of a burst with an optical afterglow
  11. GRB 060510A: Swift/UVOT Detection of an Optical Afterglow
  12. GRB060418: optical observations
  13. GRB 060428a, SMARTS optical/IR afterglow detection
  14. GRB 060510B: Swift/UVOT Upper Limits
  15. GRB 060510b: Redshift
  16. GRB060510B : Faulkes North Telescope detection
  17. GRB 060510b: Gemini NIR observations
  18. GRB 060510b: NIR observations
  19. GRB 060510B: MDM Observations and candidate OT
  20. GRB 060510: Swift detection of a burst with optical transient
  21. GRB060507: optical afterglow detection
  22. GRB060502B: improvement in the XRT afterglow position
  23. GRB 060507: Swift/UVOT Upper Limits
  24. GRB 060507: MDM Optical Upper Limit
  25. GRB060425: new MASTER survey method
  26. GRB 060502b: Second epoch Gemini observations
  27. GRB 060428B: spectroscopy
  28. GRB 060502B: optical observations
  29. GRB 060502B MDM Follow-up Observation
  30. GRB060502A, optical observation
  31. GRB 060502B: MDM Optical Observation
  32. GRB 060502B: AROMA optical observations
  33. GRB 060502B: Xinglong optical observation
  34. GRB 060502B: MASTER optical observations
  35. GRB060502: Gemini spectroscopy
  36. GRB060501: Swift UVOT followup observations
  37. GRB 060502: P60 Afterglow Confirmation
  38. GRB 060502: Swift detection of a burst with an optical counterpart
  39. GRB060501: Super-LOTIS observations
  40. GRB 060501: ROTSE-III Optical Limits
  41. GRB060428B: optical observation
  42. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  43. GRB 060428B: MDM Observations
  44. GRB 060427B: MASTER optical observations
  45. GRB060428B: Swift XRT Team refined analysis
  46. GRB 060428B: KAIT observations
  47. GRB060425:MASTER optical limit
  48. GRB060428A: Swift/UVOT observations.
  49. GRB060428B, optical observation
  50. GRB060427:MASTER optical limit
  51. GRB 060428b: Optical afterglow candidate
  52. GRB060427: Xinglong optical Observations
  53. GRB 060427: NOT observations
  54. GRB 060427, optical observation
  55. GRB060424: optical afterglow detection
  56. No OT 060420 in MASCOT images
  57. OT 060420: CONCAM detection of a candidate new magnitude 5 optical
  58. GRB060418: optical observations
  59. Konus-Wind observation of GRB 060418
  60. GRB(?)060421:MASTER optical limit
  61. Possible GRB060421: BART limits
  62. GRB 060418 : Lulin Optical follow-up
  63. GRB 060418: Radio Observations
  64. GRB060418: Optical Observations
  65. GRB 060418, SMARTS optical/IR afterglow observations
  66. GRB060418 : LT optical afterglow observation
  67. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  68. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  69. GRB060403: optical observations
  70. GRB 060403 Optical observations
  71. GRB 060403: MITSuME optical observation
  72. GRB060403: Optical Limit
  73. HETE Triggers H4043 and H4044 Not Due to New Cosmic Source
  74. HETE trigger H4044: RTT150 optical observations
  75. H4044, a Repeat Outburst From The Source of H4043 (="GRB060331")
  76. HETE Trigger 4043: ROTSE-III Optical Limits
  77. H4043, an unusual high-energy transient observed by HETE
  78. GRB 060322: LNA optical limit
  79. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  80. GRB 060323 : WIDGET simultaneous optical observations
  81. GRB 060323: Early optical observation at Xinglong
  82. GRB060218, optical observations
  83. GRB 060211A: optical observation
  84. GRB060323: optical limit
  85. GRB060211B: optical observation
  86. GRB060323: NOT optical observations
  87. GRB 060322: IAC80 optical observations
  88. GRB060323: P60 Observations
  89. GRB 060323: Swift/UVOT Observations
  90. GRB 060323: optical afterglow confirmed
  91. GRB060323: NOT observations
  92. GRB 060323: Optical Observations
  93. GRB 060323: optical observations at TNG
  94. GRB060323, optical observation
  95. GRB 060323: Swift detection of a burst with a possible optical afterglow
  96. GRB060219: optical observation
  97. GRB060206: optical observation
  98. GRB060218/SN2006aj: optical observations
  99. GRB 060218/SN 2006aj, LNA optical observation
  100. GRB 060319: IAC-80 optical observations

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