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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"

16155 results found.

  1. GRB 060502B: Xinglong optical observation
  2. GRB 060502B: MASTER optical observations
  3. GRB060502: Gemini spectroscopy
  4. GRB060501: Swift UVOT followup observations
  5. GRB 060502: P60 Afterglow Confirmation
  6. GRB 060502: Swift detection of a burst with an optical counterpart
  7. GRB060501: Super-LOTIS observations
  8. GRB 060501: ROTSE-III Optical Limits
  9. GRB060428B: optical observation
  10. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  11. GRB 060428B: MDM Observations
  12. GRB 060427B: MASTER optical observations
  13. GRB060428B: Swift XRT Team refined analysis
  14. GRB 060428B: KAIT observations
  15. GRB060425:MASTER optical limit
  16. GRB060428A: Swift/UVOT observations.
  17. GRB060428B, optical observation
  18. GRB060427:MASTER optical limit
  19. GRB 060428b: Optical afterglow candidate
  20. GRB060427: Xinglong optical Observations
  21. GRB 060427: NOT observations
  22. GRB 060427, optical observation
  23. GRB060424: optical afterglow detection
  24. No OT 060420 in MASCOT images
  25. OT 060420: CONCAM detection of a candidate new magnitude 5 optical
  26. GRB060418: optical observations
  27. Konus-Wind observation of GRB 060418
  28. GRB(?)060421:MASTER optical limit
  29. Possible GRB060421: BART limits
  30. GRB 060418 : Lulin Optical follow-up
  31. GRB 060418: Radio Observations
  32. GRB060418: Optical Observations
  33. GRB 060418, SMARTS optical/IR afterglow observations
  34. GRB060418 : LT optical afterglow observation
  35. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  36. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  37. GRB060403: optical observations
  38. GRB 060403 Optical observations
  39. GRB 060403: MITSuME optical observation
  40. GRB060403: Optical Limit
  41. HETE Triggers H4043 and H4044 Not Due to New Cosmic Source
  42. HETE trigger H4044: RTT150 optical observations
  43. H4044, a Repeat Outburst From The Source of H4043 (="GRB060331")
  44. HETE Trigger 4043: ROTSE-III Optical Limits
  45. H4043, an unusual high-energy transient observed by HETE
  46. GRB 060322: LNA optical limit
  47. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  48. GRB 060323 : WIDGET simultaneous optical observations
  49. GRB 060323: Early optical observation at Xinglong
  50. GRB060218, optical observations
  51. GRB 060211A: optical observation
  52. GRB060323: optical limit
  53. GRB060211B: optical observation
  54. GRB060323: NOT optical observations
  55. GRB 060322: IAC80 optical observations
  56. GRB060323: P60 Observations
  57. GRB 060323: Swift/UVOT Observations
  58. GRB 060323: optical afterglow confirmed
  59. GRB060323: NOT observations
  60. GRB 060323: Optical Observations
  61. GRB 060323: optical observations at TNG
  62. GRB060323, optical observation
  63. GRB 060323: Swift detection of a burst with a possible optical afterglow
  64. GRB060219: optical observation
  65. GRB060206: optical observation
  66. GRB060218/SN2006aj: optical observations
  67. GRB 060218/SN 2006aj, LNA optical observation
  68. GRB 060319: IAC-80 optical observations
  69. GRB 060319: Re-analysis of TNG data
  70. GRB 060319 optical observations at TNG
  71. GRB060319 : Liverpool Telescope optical limit
  72. GRB060319: MASTER optical observation
  73. GRB060313: Radio Observations
  74. GRB 060313: early afterglow NIR upper limits with REM
  75. GRB 060313: Swift-XRT team refined analysis
  76. GRB060313: optical observations of the afterglow candidate
  77. GRB 060313, SMARTS optical counterpart?
  78. GRB 060313: Possible optical counterpart
  79. GRB 060313, SMARTS optical/IR observations
  80. GRB060313: optical and near infrared observations with REM
  81. GRB 060312: ROTSE-III Optical Limits
  82. GRB060218: analysis of the XMM-Newton observation
  83. GRB 060218: RTT150 optical observations
  84. GRB060223b: optical limit
  85. GRB060218/SN 2006aj: optical observation in V
  86. GRB060218/SN 2006aj: optical observation
  87. GRB 060121: HST observations
  88. GRB 060218/SN 2006aj: K-380 optical observations
  89. GRB 060218/SN 2006aj, SMARTS optical/IR observations
  90. GRB200618: optical polarimetry and photometry
  91. GRB 060218/SN 2006aj: ABT observations
  92. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  93. GRB 060218 : Radio upper limits from GMRT
  94. GRB 060218/SN 2006aj: WIRO optical observations
  95. GRB 060218/SN 2006aj: RBO optical observations
  96. GRB 060204B: GETS early limit
  97. GRB 060223A:Xinglong optical limits
  98. GRB 060223B: ART optical limits
  99. GRB 060218: rebrightening
  100. Correction to GCN 4816 on GRB060218

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