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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"

16149 results found.

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

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