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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"

39191 results found.

  1. GRB 020410, optical observations
  2. BeppoSAX ALERT: possible GRB020411
  3. GRB 020409, optical observations
  4. GRB 020409: Optical Observations
  5. GRB020406(?), optical observations
  6. GRB020410, optical observations
  7. BeppoSAX ALERT: possible GRB020410
  8. X-ray afterglow of GRB020321
  9. BeppoSAX GRB : GRB020409
  10. GRB020405: VLT optical observations and V band decay slope
  11. GRB020331 optical observations with RIMOTS
  12. GRB020124 optical observations with RIBOTS/RIMOTS
  13. GRB 020321: Candidate X-ray Counterparts
  14. ASM GRB candidate 020406 refined error box
  15. GRB 020405: Moderate-resolution spectroscopy
  16. GRB020406(?), optical observations
  17. GRB020405: VLT optical observations
  18. Revised Photometry of the Optical Afterglow of GRB 020405
  19. GRB020405: OT observations
  20. GRB 020331: Candidate Optical Afterglow
  21. GRB 020405: Decay index
  22. Short RXTE/ASM transient 020406; may be a GRB
  23. GRB020405, Radio Observations
  24. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  25. GRB 020405, U-band observations
  26. GRB 020405: Optical afterglow candidate
  27. IPN localization of GRB020405
  28. GRB011212: Optical Observations
  29. GRB 020331: NIR Observations
  30. GRB 020331: NIR Observations
  31. GRB020331 NIR observation at KPNO (re-submission)
  32. GRB02033 NIR observation at KPNO
  33. GRB020331 field photometry
  34. GRB 020331 Optical Observations
  35. GRB 020331, NIR observations
  36. GRB 020331: Optical observations
  37. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  38. GRB 020321: Infrared observations
  39. GRB 020322: BeppoSAX observations of the X-ray afterglow
  40. SN 2002ap - peak brightness date (SN/GRB?)
  41. GRB 020322, Radio observations
  42. Near-Infrared Observations of GRB020322 at TIRGO
  43. GRB 020321, Radio Observations
  44. GRB 020322: Optical Observations
  45. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  46. GRB 020321: Optical observations
  47. GRB020317 BVRI field photometry
  48. GRB011211 revised BVRI field photometry
  49. GRB020305 BVRI field photometry
  50. GRB020322 BVRI field photometry
  51. GRB 020322 optical observations
  52. GRB 020322 optical observation
  53. GRB020317 : Near IR Observations from Mt Abu Observatory
  54. GRB 020322: Optical Sources and Improved Astrometry
  55. GRB020322, optical observations
  56. GRB 020322: Optical candidate
  57. GRB020322: BeppoSAX/NFI Observations
  58. Bepposax GRB020322 The second springtime BSAX GRB
  59. GRB 020321: Optical observations
  60. GRB 011121: Fourth Epoch of HST Imaging
  61. GRB020317: optical observations
  62. GRB020321 optical observations
  63. GRB020321: BeppoSAX/NFI Observations
  64. GRB020321: a faint BeppoSAX detection
  65. GRB020305: NIR observations
  66. GRB 020317 : KISO Optical Observations
  67. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  68. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  69. GRB 020305: Optical Observations
  70. GRB020317, optical observations
  71. GRB 020317: Optical observations
  72. GRB 011121: Third HST Epoch
  73. GRB020305: Properties of the Candidate Optical Afterglow
  74. GRB 011121: HST Observations reveal an intermediate-time multicolor
  75. GRB011121, possible supernova association
  76. GRB011130 (XRF011130) Second Epoch Chandra Observations
  77. GRB020305: Subaru Optical Observations
  78. GRB 020305: Optical observations
  79. XRF/GRB 011030 Images
  80. XRF/GRB 011030: Detection of the Probable Host Galaxy
  81. GRB 020305: Candidate optical afterglow
  82. Type Ic SN2002bl (SN/GRB?) Radio Observations
  83. GRB020305: Optical Observations
  84. IPN triangulation of GRB020305 (HETE 1939)
  85. GRB020305 (=H1939): Localization of a GRB by HETE
  86. GRB 020305: Optical observations
  87. HST Imaging of the afterglow and host of GRB 011121
  88. GRB 010921: HST Observations
  89. IPN detection and localization of Cygnus X-1 flares
  90. GRB020127: Further VLA Observations of Possible Counterparts
  91. IPN detection of further SGR1900+14 activity
  92. SGR1900+14 activity
  93. IPN/HETE Detection of Bursts from SGR1900+14
  94. IPN Upper Limits to a GRB Associated With SN2002ap
  95. GRB020124 BVRI field photometry
  96. GRB020127: Palomar and VLA Observations of Possible Counterparts
  97. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  98. SN2002ap (SN/GRB?) Echelle spectra
  99. SN2002ap (SN/GRB?) optical spectrographic observations
  100. GRB020127 Optical Observations

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