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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"

25996 results found.

  1. GRB020331 NIR observation at KPNO (re-submission)
  2. GRB02033 NIR observation at KPNO
  3. GRB020331 field photometry
  4. GRB 020331, NIR observations
  5. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  6. GRB 020322: BeppoSAX observations of the X-ray afterglow
  7. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  8. Near-Infrared Observations of GRB020322 at TIRGO
  9. GRB 020321, Radio Observations
  10. GRB 020322: Optical Observations
  11. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  12. GRB 020321: Optical observations
  13. GRB020317 BVRI field photometry
  14. GRB011211 revised BVRI field photometry
  15. GRB020305 BVRI field photometry
  16. GRB020322 BVRI field photometry
  17. GRB 020322: Optical Sources and Improved Astrometry
  18. GRB020317: optical observations
  19. GRB020321 optical observations
  20. GRB020321: a faint BeppoSAX detection
  21. GRB 020317 : KISO Optical Observations
  22. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  23. GRB 020305: Optical Observations
  24. GRB020317, optical observations
  25. GRB 020317: Optical observations
  26. GRB 011121: Third HST Epoch
  27. GRB020305: Properties of the Candidate Optical Afterglow
  28. GRB 011121: HST Observations reveal an intermediate-time multicolor
  29. GRB011130 (XRF011130) Second Epoch Chandra Observations
  30. GRB020305: Subaru Optical Observations
  31. XRF/GRB 011030: Detection of the Probable Host Galaxy
  32. GRB 020305: Candidate optical afterglow
  33. GRB020305, optical observations
  34. IPN triangulation of GRB020305 (HETE 1939)
  35. GRB020305 (=H1939): Localization of a GRB by HETE
  36. HST Imaging of the afterglow and host of GRB 011121
  37. IPN detection and localization of Cygnus X-1 flares
  38. SGR1900+14 activity
  39. IPN Upper Limits to a GRB Associated With SN2002ap
  40. GRB020124 BVRI field photometry
  41. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  42. SN2002ap (SN/GRB?) Echelle spectra
  43. GRB020127 Optical Observations
  44. SN 2002ap in M74
  45. SN2002ap (SN/GRB?) UBVRI Field Photometry
  46. GRB020127: Chandra Observations and Prospective Counterparts
  47. pre-SN2002ap (SN/GRB?) imaging of M74
  48. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  49. GRB020124, optical observations
  50. GRB 020127, I-band observations starting 3.14-hr after the event
  51. GRB010921 Optical Observations
  52. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  53. GRB020124: Optical observations
  54. GRB 020124: Optical observations
  55. GRB 020124: Optical afterglow
  56. GRB020124(=H1896): Localization of a Long GRB by HETE
  57. Possible optical counterpart to a GRB
  58. GRB011212, Optical Observations
  59. Optical polarization observations for GRB011211
  60. GRB 011211: Detection of the Probable Host Galaxy
  61. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  62. GRB 011130: Optical Observations of X-ray and Radio Sources
  63. GRB 011212: optical observation at Asiago
  64. GRB 011211: Evidence for an Optical Break
  65. GRB 011211: TNG Spectroscopic Observations
  66. optical follow-up of GRB(XRF) 011211
  67. GRB 011212: optical observation at Oslo (relayed)
  68. GRB 011211, Optical Observations
  69. GRB011212, BVRI field photometry
  70. GRB011211, BVRI field photometry
  71. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  72. Fading of the optical source associated of XRF 011211
  73. GRB 011211 Optical Observations: Likely Afterglow
  74. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  75. GRB011130 (XRF011130) Chandra Observations
  76. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  77. GRB 011130, K band observations
  78. GRB011130, optical observations
  79. GRB011130 (=XRF011130): Second Revised Localization by HETE
  80. GRB011130 (XRF011130) SDSS PT i-band observations
  81. XRF011130: Infrared Observations
  82. GRB 011121
  83. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  84. GRB 011121: J-band observations
  85. GRB 011121: NIR observations, host galaxy?
  86. GRB011121: UBRI Observations
  87. GRB 011121 J-Band Astrometry
  88. GRB 011121: Detection of Bright IR Counterpart
  89. GRB011121: possible redshift, continued decay
  90. GRB 011030: TNG K-band observation
  91. XRF011030: J and K band observations
  92. XRF011030: Chandra Observations
  93. GRB011030: Z-band observations
  94. GRB 011030 R band observations
  95. GRB 011030 I-band Observation
  96. The X-ray Flash 011030 ('GRB 011030')
  97. Non-triggered burst 011030 ("GRB 011030")
  98. The Radio Afterglow from the X-ray Rich GRB 011030
  99. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  100. GRB 970828: HST Observations of the Host Galaxy

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