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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"

41739 results found.

  1. GRB 020405, U-band observations
  2. GRB 020405: Optical afterglow candidate
  3. IPN localization of GRB020405
  4. GRB011212: Optical Observations
  5. GRB 020331: NIR Observations
  6. GRB 020331: NIR Observations
  7. GRB020331 NIR observation at KPNO (re-submission)
  8. GRB02033 NIR observation at KPNO
  9. GRB020331 field photometry
  10. GRB 020331 Optical Observations
  11. GRB 020331, NIR observations
  12. GRB 020331: Optical observations
  13. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  14. GRB 020321: Infrared observations
  15. GRB 020322: BeppoSAX observations of the X-ray afterglow
  16. SN 2002ap - peak brightness date (SN/GRB?)
  17. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  18. GRB 020322, Radio observations
  19. Near-Infrared Observations of GRB020322 at TIRGO
  20. GRB 020321, Radio Observations
  21. GRB 020322: Optical Observations
  22. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  23. GRB 020321: Optical observations
  24. GRB020317 BVRI field photometry
  25. GRB011211 revised BVRI field photometry
  26. GRB020305 BVRI field photometry
  27. GRB020322 BVRI field photometry
  28. GRB 020322 optical observations
  29. GRB020322: Candidate Optical Afterglow
  30. GRB 020322 optical observation
  31. GRB020317 : Near IR Observations from Mt Abu Observatory
  32. GRB 020322: Optical Sources and Improved Astrometry
  33. GRB020322, optical observations
  34. GRB 020322: Optical candidate
  35. XMM-Newton observation of GRB020322
  36. GRB020322: Optical Observations
  37. GRB 011121: Fourth Epoch of HST Imaging
  38. GRB020317: optical observations
  39. GRB020321 optical observations
  40. GRB020321: BeppoSAX/NFI Observations
  41. GRB020321: a faint BeppoSAX detection
  42. GRB020305: NIR observations
  43. GRB 020317 : KISO Optical Observations
  44. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  45. GRB 020305: Optical Observations
  46. GRB020317, optical observations
  47. GRB 020317: Optical observations
  48. GRB 011121: Third HST Epoch
  49. GRB020305: Properties of the Candidate Optical Afterglow
  50. GRB 011121: HST Observations reveal an intermediate-time multicolor
  51. GRB011121, possible supernova association
  52. GRB011130 (XRF011130) Second Epoch Chandra Observations
  53. GRB020305: Subaru Optical Observations
  54. GRB 020305: Optical observations
  55. XRF/GRB 011030: Detection of the Probable Host Galaxy
  56. GRB 020305: Candidate optical afterglow
  57. Type Ic SN2002bl (SN/GRB?) Radio Observations
  58. GRB020305, optical observations
  59. GRB020305: Optical Observations
  60. IPN triangulation of GRB020305 (HETE 1939)
  61. GRB020305 (=H1939): Localization of a GRB by HETE
  62. GRB 020305: Optical observations
  63. HST Imaging of the afterglow and host of GRB 011121
  64. GRB 010921: HST Observations
  65. IPN detection and localization of Cygnus X-1 flares
  66. GRB020127: Further VLA Observations of Possible Counterparts
  67. RXTE Observations of SGR 1900+14
  68. IPN detection of further SGR1900+14 activity
  69. SGR1900+14 activity
  70. IPN/HETE Detection of Bursts from SGR1900+14
  71. IPN Upper Limits to a GRB Associated With SN2002ap
  72. GRB020124 BVRI field photometry
  73. GRB020127: Palomar and VLA Observations of Possible Counterparts
  74. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  75. SN2002ap (SN/GRB?) Echelle spectra
  76. SN2002ap (SN/GRB?) optical spectrographic observations
  77. GRB020127, WSRT radio observations
  78. GRB020127 Optical Observations
  79. SN 2002ap (SN/GRB?)
  80. SN 2002ap in M74
  81. SN2002ap (SN/GRB?) UBVRI Field Photometry
  82. GRB020127: Chandra Observations and Prospective Counterparts
  83. pre-SN2002ap (SN/GRB?) imaging of M74
  84. Type Ib/c SN2002ap (SN/GRB?)
  85. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  86. GRB020124, optical observations
  87. GRB020127: Optical observations
  88. GRB 020127, I-band observations starting 3.14-hr after the event
  89. IPN detection of further activity from SGR1806-20
  90. IPN triangulation of GRB020127 (=H1902)
  91. GRB010921 Optical Observations
  92. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  93. GRB020124: Optical observations
  94. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  95. GRB020124: Optical observations
  96. GRB 020124: Optical observations
  97. GRB 020124 Optical Observations
  98. IPN triangulation of GRB020124 (HETE 1896)
  99. IPN observations of SGR1806-20
  100. GRB 020124: Optical afterglow

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