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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"

27392 results found.

  1. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  2. GRB 020322: BeppoSAX observations of the X-ray afterglow
  3. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  4. Near-Infrared Observations of GRB020322 at TIRGO
  5. GRB 020321, Radio Observations
  6. GRB 020322: Optical Observations
  7. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  8. GRB 020321: Optical observations
  9. GRB020317 BVRI field photometry
  10. GRB011211 revised BVRI field photometry
  11. GRB020305 BVRI field photometry
  12. GRB020322 BVRI field photometry
  13. GRB 020322: Optical Sources and Improved Astrometry
  14. GRB020317: optical observations
  15. GRB020321 optical observations
  16. GRB020321: a faint BeppoSAX detection
  17. GRB 020317 : KISO Optical Observations
  18. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  19. GRB 020305: Optical Observations
  20. GRB020317, optical observations
  21. GRB 020317: Optical observations
  22. GRB 011121: Third HST Epoch
  23. GRB020305: Properties of the Candidate Optical Afterglow
  24. GRB 011121: HST Observations reveal an intermediate-time multicolor
  25. GRB011130 (XRF011130) Second Epoch Chandra Observations
  26. GRB020305: Subaru Optical Observations
  27. XRF/GRB 011030: Detection of the Probable Host Galaxy
  28. GRB 020305: Candidate optical afterglow
  29. GRB020305, optical observations
  30. IPN triangulation of GRB020305 (HETE 1939)
  31. GRB020305 (=H1939): Localization of a GRB by HETE
  32. HST Imaging of the afterglow and host of GRB 011121
  33. IPN detection and localization of Cygnus X-1 flares
  34. SGR1900+14 activity
  35. IPN Upper Limits to a GRB Associated With SN2002ap
  36. GRB020124 BVRI field photometry
  37. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  38. SN2002ap (SN/GRB?) Echelle spectra
  39. GRB020127 Optical Observations
  40. SN 2002ap in M74
  41. SN2002ap (SN/GRB?) UBVRI Field Photometry
  42. GRB020127: Chandra Observations and Prospective Counterparts
  43. pre-SN2002ap (SN/GRB?) imaging of M74
  44. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  45. GRB020124, optical observations
  46. GRB 020127, I-band observations starting 3.14-hr after the event
  47. GRB010921 Optical Observations
  48. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  49. GRB020124: Optical observations
  50. GRB 020124: Optical observations
  51. GRB 020124: Optical afterglow
  52. GRB020124(=H1896): Localization of a Long GRB by HETE
  53. Possible optical counterpart to a GRB
  54. GRB011212, Optical Observations
  55. Optical polarization observations for GRB011211
  56. GRB 011211: Detection of the Probable Host Galaxy
  57. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  58. GRB 011130: Optical Observations of X-ray and Radio Sources
  59. GRB 011212: optical observation at Asiago
  60. GRB 011211: Evidence for an Optical Break
  61. GRB 011211: TNG Spectroscopic Observations
  62. optical follow-up of GRB(XRF) 011211
  63. GRB 011212: optical observation at Oslo (relayed)
  64. GRB 011211, Optical Observations
  65. GRB011212, BVRI field photometry
  66. GRB011211, BVRI field photometry
  67. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  68. Fading of the optical source associated of XRF 011211
  69. GRB 011211 Optical Observations: Likely Afterglow
  70. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  71. GRB011130 (XRF011130) Chandra Observations
  72. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  73. GRB 011130, K band observations
  74. GRB011130, optical observations
  75. GRB011130 (=XRF011130): Second Revised Localization by HETE
  76. GRB011130 (XRF011130) SDSS PT i-band observations
  77. XRF011130: Infrared Observations
  78. GRB 011121
  79. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  80. GRB 011121: J-band observations
  81. GRB 011121: NIR observations, host galaxy?
  82. GRB011121: UBRI Observations
  83. GRB 011121 J-Band Astrometry
  84. GRB 011121: Detection of Bright IR Counterpart
  85. GRB011121: possible redshift, continued decay
  86. GRB 011030: TNG K-band observation
  87. XRF011030: J and K band observations
  88. XRF011030: Chandra Observations
  89. GRB011030: Z-band observations
  90. GRB 011030 R band observations
  91. GRB 011030 I-band Observation
  92. The X-ray Flash 011030 ('GRB 011030')
  93. Non-triggered burst 011030 ("GRB 011030")
  94. The Radio Afterglow from the X-ray Rich GRB 011030
  95. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  96. GRB 970828: HST Observations of the Host Galaxy
  97. GRB 000131: HST Detection of the Host Galaxy
  98. GRB 970828: HST Observations of the Host Galaxy
  99. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  100. GRB011019: Subaru Optical Observations

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