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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"

15684 results found.

  1. GRB060319: MASTER optical observation
  2. GRB060313: Radio Observations
  3. GRB 060313: early afterglow NIR upper limits with REM
  4. GRB 060313: Swift-XRT team refined analysis
  5. GRB060313: optical observations of the afterglow candidate
  6. GRB 060313, SMARTS optical counterpart?
  7. GRB 060313: Possible optical counterpart
  8. GRB 060313, SMARTS optical/IR observations
  9. GRB060313: optical and near infrared observations with REM
  10. GRB 060312: ROTSE-III Optical Limits
  11. GRB060218: analysis of the XMM-Newton observation
  12. GRB 060218: RTT150 optical observations
  13. GRB060223b: optical limit
  14. GRB060218/SN 2006aj: optical observation in V
  15. GRB060218/SN 2006aj: optical observation
  16. GRB 060121: HST observations
  17. GRB 060218/SN 2006aj: K-380 optical observations
  18. GRB 060218/SN 2006aj, SMARTS optical/IR observations
  19. GRB200618: optical polarimetry and photometry
  20. GRB 060218/SN 2006aj: ABT observations
  21. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  22. GRB 060218 : Radio upper limits from GMRT
  23. GRB 060218/SN 2006aj: WIRO optical observations
  24. GRB 060218/SN 2006aj: RBO optical observations
  25. GRB 060204B: GETS early limit
  26. GRB 060223A:Xinglong optical limits
  27. GRB 060223B: ART optical limits
  28. GRB 060218: rebrightening
  29. Correction to GCN 4816 on GRB060218
  30. GRB 060218/SN 2006aj: optical observations
  31. GRB060218: Optical brightening in V and R
  32. GRB 060223: Keck redshift
  33. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  34. Spectral properties of GRB060218/SN2006aj
  35. GRB 060218: rebrightening
  36. GRB 060218: emergence of the underlying SN spectrum
  37. GRB 060218: Decline in r-band flux
  38. GRB 060218: spectroscopic observations
  39. GRB060218: Optical Spectroscopy of GRB-SN
  40. GRB060218: VLT spectroscopy
  41. GRB 060218: Optical Observations at Xinglong Obs.
  42. GRB060218: UV Detection and Light Curves
  43. GRB060218: Radio Afterglow Discovery
  44. GRB 060218: MDM Redshift
  45. GRB 060218: optical/nIR observations at La Palma
  46. Oddball GRB 060218, transient or GRB?
  47. Brightening of the Optical Counterpart of the Possible GRB 060218
  48. GRB 060218: MDM Observations
  49. GRB 060218A: ROTSE-III Possible Optical Flare
  50. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  51. GRB 060213: optical afterglow not confirmed
  52. Swift UVOT observations of GRB060213
  53. GRB 060213: optical afterglow candidate
  54. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  55. GRB 060211b: WIRO NIR Observations
  56. GRB060213:_MASTER_optical_observation
  57. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  58. GRB 060210: Radio Observations
  59. GRB 060211a: WIRO NIR Observations
  60. GRB060211B: REM optical and NIR observations
  61. GRB060121: optical observations
  62. GRB060110: optical observations
  63. GRB060105: optical observations
  64. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  65. GRB 060206: SOAR Detections
  66. GRB 050826: Optical Afterglow and Host Galaxy
  67. GRB060211b: optical observation
  68. GRB 060210: Optical Observations
  69. GRB060211: Faulkes North observation
  70. GRB 060211: ROTSE-III Optical Limits
  71. GRB060210: Swift XRT Refined Analysis
  72. GRB060206, optical observations
  73. GRB 060210 : Xinglong and Lulin optical limit
  74. GRB060210: Optical Observations
  75. GRB060210: Gemini absorption spectroscopy
  76. GRB060210: Early Optical Observations
  77. GRB 060210: optical evolution
  78. GRB060210: Optical afterglow
  79. GRB060209: RTT150 optical observations
  80. GRB 060209 : TAROT optical observation
  81. GRB060209A: MASTER optical observation
  82. GRB 060206: WSRT Radio Observations
  83. GRB 060206: More PROMPT Detections
  84. GRB 060121 : WIDGET Pre-trigger limit
  85. GRB 060206: optical observations at Asiago
  86. Orphan GRB Afterglow candidate
  87. GRB 060206: Subaru/FOCAS optical spectroscopy
  88. GRB 060206: Super-LOTIS observations
  89. GRB060204A: Swift/UVOT observations
  90. GRB 060206 : Lulin optical observations
  91. GRB060206: Swift XRT Refined Analysis
  92. GRB060206: Liverpool Telescope observation
  93. GRB060206: P60 Optical Observations
  94. GRB060206: Swift XRT Position
  95. GRB 060206: RAPTOR observations of afterglow candidate variability.
  96. GRB 060206: High redshift burst
  97. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  98. GRB060206: Optical afterglow
  99. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  100. GRB060203: WHT Z-band observations

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