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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"

35272 results found.

  1. GRB020410: BeppoSAX NFI observation
  2. GRB 020409: Optical observations
  3. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  4. GRB 020410, optical observations
  5. BeppoSAX ALERT: possible GRB020411
  6. GRB 020409, optical observations
  7. GRB 020409: Optical Observations
  8. GRB020406(?), optical observations
  9. GRB020410, optical observations
  10. BeppoSAX ALERT: possible GRB020410
  11. X-ray afterglow of GRB020321
  12. BeppoSAX GRB : GRB020409
  13. GRB020405: VLT optical observations and V band decay slope
  14. GRB020331 optical observations with RIMOTS
  15. GRB020124 optical observations with RIBOTS/RIMOTS
  16. GRB 020321: Candidate X-ray Counterparts
  17. ASM GRB candidate 020406 refined error box
  18. GRB 020405: Moderate-resolution spectroscopy
  19. GRB020406(?), optical observations
  20. GRB020405: VLT optical observations
  21. Revised Photometry of the Optical Afterglow of GRB 020405
  22. GRB020405: OT observations
  23. GRB 020331: Candidate Optical Afterglow
  24. GRB 020405: Decay index
  25. Short RXTE/ASM transient 020406; may be a GRB
  26. GRB020405, Radio Observations
  27. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  28. GRB 020405, U-band observations
  29. GRB 020405: Optical afterglow candidate
  30. IPN localization of GRB020405
  31. GRB011212: Optical Observations
  32. GRB 020331: NIR Observations
  33. GRB 020331: NIR Observations
  34. GRB020331 NIR observation at KPNO (re-submission)
  35. GRB02033 NIR observation at KPNO
  36. GRB020331 field photometry
  37. GRB 020331 Optical Observations
  38. GRB 020331, NIR observations
  39. GRB 020331: Optical observations
  40. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  41. GRB 020321: Infrared observations
  42. GRB 020322: BeppoSAX observations of the X-ray afterglow
  43. SN 2002ap - peak brightness date (SN/GRB?)
  44. GRB 020322, Radio observations
  45. Near-Infrared Observations of GRB020322 at TIRGO
  46. GRB 020321, Radio Observations
  47. GRB 020322: Optical Observations
  48. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  49. GRB 020321: Optical observations
  50. GRB020317 BVRI field photometry
  51. GRB011211 revised BVRI field photometry
  52. GRB020305 BVRI field photometry
  53. GRB020322 BVRI field photometry
  54. GRB 020322 optical observations
  55. GRB 020322 optical observation
  56. GRB020317 : Near IR Observations from Mt Abu Observatory
  57. GRB 020322: Optical Sources and Improved Astrometry
  58. GRB020322, optical observations
  59. GRB 020322: Optical candidate
  60. GRB020322: BeppoSAX/NFI Observations
  61. Bepposax GRB020322 The second springtime BSAX GRB
  62. GRB 020321: Optical observations
  63. GRB 011121: Fourth Epoch of HST Imaging
  64. GRB020317: optical observations
  65. GRB020321 optical observations
  66. GRB020321: BeppoSAX/NFI Observations
  67. GRB020321: a faint BeppoSAX detection
  68. GRB 020317 : KISO Optical Observations
  69. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  70. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  71. GRB 020305: Optical Observations
  72. GRB020317, optical observations
  73. GRB 020317: Optical observations
  74. GRB 011121: Third HST Epoch
  75. GRB020305: Properties of the Candidate Optical Afterglow
  76. GRB 011121: HST Observations reveal an intermediate-time multicolor
  77. GRB011121, possible supernova association
  78. GRB011130 (XRF011130) Second Epoch Chandra Observations
  79. GRB020305: Subaru Optical Observations
  80. GRB 020305: Optical observations
  81. XRF/GRB 011030 Images
  82. XRF/GRB 011030: Detection of the Probable Host Galaxy
  83. GRB 020305: Candidate optical afterglow
  84. Type Ic SN2002bl (SN/GRB?) Radio Observations
  85. GRB020305: Optical Observations
  86. IPN triangulation of GRB020305 (HETE 1939)
  87. GRB020305 (=H1939): Localization of a GRB by HETE
  88. GRB 020305: Optical observations
  89. HST Imaging of the afterglow and host of GRB 011121
  90. GRB 010921: HST Observations
  91. IPN detection and localization of Cygnus X-1 flares
  92. GRB020127: Further VLA Observations of Possible Counterparts
  93. IPN detection of further SGR1900+14 activity
  94. SGR1900+14 activity
  95. IPN/HETE Detection of Bursts from SGR1900+14
  96. IPN Upper Limits to a GRB Associated With SN2002ap
  97. GRB020124 BVRI field photometry
  98. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  99. SN2002ap (SN/GRB?) Echelle spectra
  100. SN2002ap (SN/GRB?) optical spectrographic observations

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