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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"

37101 results found.

  1. X-ray afterglow of GRB020321
  2. BeppoSAX GRB : GRB020409
  3. GRB020331: Confirmation of Afterglow Candidate with Magellan
  4. GRB020405: VLT optical observations and V band decay slope
  5. GRB020331 optical observations with RIMOTS
  6. GRB020124 optical observations with RIBOTS/RIMOTS
  7. GRB 020321: Candidate X-ray Counterparts
  8. ASM GRB candidate 020406 refined error box
  9. GRB 020405: Moderate-resolution spectroscopy
  10. GRB020406(?), optical observations
  11. GRB020405: VLT optical observations
  12. Revised Photometry of the Optical Afterglow of GRB 020405
  13. GRB020405: OT observations
  14. GRB 020331: Candidate Optical Afterglow
  15. GRB 020405: Decay index
  16. Short RXTE/ASM transient 020406; may be a GRB
  17. GRB020405, Radio Observations
  18. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  19. GRB 020405, U-band observations
  20. GRB 020405: Optical afterglow candidate
  21. IPN localization of GRB020405
  22. GRB011212: Optical Observations
  23. GRB 020331: NIR Observations
  24. GRB 020331: NIR Observations
  25. GRB020331 NIR observation at KPNO (re-submission)
  26. GRB02033 NIR observation at KPNO
  27. GRB020331 field photometry
  28. GRB 020331 Optical Observations
  29. GRB 020331, NIR observations
  30. GRB 020331: Optical observations
  31. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  32. GRB 020321: Infrared observations
  33. GRB 020322: BeppoSAX observations of the X-ray afterglow
  34. SN 2002ap - peak brightness date (SN/GRB?)
  35. GRB 020322, Radio observations
  36. Near-Infrared Observations of GRB020322 at TIRGO
  37. GRB 020321, Radio Observations
  38. GRB 020322: Optical Observations
  39. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  40. GRB 020321: Optical observations
  41. GRB020317 BVRI field photometry
  42. GRB011211 revised BVRI field photometry
  43. GRB020305 BVRI field photometry
  44. GRB020322 BVRI field photometry
  45. GRB 020322 optical observations
  46. GRB 020322 optical observation
  47. GRB020317 : Near IR Observations from Mt Abu Observatory
  48. GRB 020322: Optical Sources and Improved Astrometry
  49. GRB020322, optical observations
  50. GRB 020322: Optical candidate
  51. GRB020322: Optical Observations
  52. GRB020322: BeppoSAX/NFI Observations
  53. Bepposax GRB020322 The second springtime BSAX GRB
  54. GRB 020321: Optical observations
  55. GRB 011121: Fourth Epoch of HST Imaging
  56. GRB020317: optical observations
  57. GRB020321 optical observations
  58. GRB020321: BeppoSAX/NFI Observations
  59. GRB020321: a faint BeppoSAX detection
  60. GRB 020317 : KISO Optical Observations
  61. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  62. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  63. GRB 020305: Optical Observations
  64. GRB020317, optical observations
  65. GRB 020317: Optical observations
  66. GRB 011121: Third HST Epoch
  67. GRB020305: Properties of the Candidate Optical Afterglow
  68. GRB 011121: HST Observations reveal an intermediate-time multicolor
  69. GRB011121, possible supernova association
  70. GRB011130 (XRF011130) Second Epoch Chandra Observations
  71. GRB020305: Subaru Optical Observations
  72. GRB 020305: Optical observations
  73. XRF/GRB 011030 Images
  74. XRF/GRB 011030: Detection of the Probable Host Galaxy
  75. GRB 020305: Candidate optical afterglow
  76. Type Ic SN2002bl (SN/GRB?) Radio Observations
  77. GRB020305: Optical Observations
  78. IPN triangulation of GRB020305 (HETE 1939)
  79. GRB020305 (=H1939): Localization of a GRB by HETE
  80. GRB 020305: Optical observations
  81. HST Imaging of the afterglow and host of GRB 011121
  82. GRB 010921: HST Observations
  83. IPN detection and localization of Cygnus X-1 flares
  84. GRB020127: Further VLA Observations of Possible Counterparts
  85. IPN detection of further SGR1900+14 activity
  86. SGR1900+14 activity
  87. IPN/HETE Detection of Bursts from SGR1900+14
  88. IPN Upper Limits to a GRB Associated With SN2002ap
  89. GRB020124 BVRI field photometry
  90. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  91. SN2002ap (SN/GRB?) Echelle spectra
  92. SN2002ap (SN/GRB?) optical spectrographic observations
  93. GRB020127 Optical Observations
  94. SN 2002ap (SN/GRB?)
  95. SN2002ap (SN/GRB?) UBVRI Field Photometry
  96. GRB020127: Chandra Observations and Prospective Counterparts
  97. pre-SN2002ap (SN/GRB?) imaging of M74
  98. SN 2002ap (hypernova / GRB ??): special list on VSNET
  99. Type Ib/c SN2002ap (SN/GRB?)
  100. Type Ib/c SN2002ap (SN/GRB?) Radio Observations

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