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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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19142 results found.

  1. GRB011212: Optical Observations
  2. GRB 020331: NIR Observations
  3. GRB 020331: NIR Observations
  4. GRB020331 NIR observation at KPNO (re-submission)
  5. GRB02033 NIR observation at KPNO
  6. GRB 020331 Optical Observations
  7. GRB 020331, NIR observations
  8. GRB 020331: Optical observations
  9. GRB 020321: Infrared observations
  10. GRB 020322: BeppoSAX observations of the X-ray afterglow
  11. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  12. GRB 020322, Radio observations
  13. Near-Infrared Observations of GRB020322 at TIRGO
  14. GRB 020321, Radio Observations
  15. GRB 020322: Optical Observations
  16. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  17. GRB 020321: Optical observations
  18. GRB 020322 optical observations
  19. GRB020317 : Near IR Observations from Mt Abu Observatory
  20. GRB020322, optical observations
  21. GRB020322: Optical Observations
  22. GRB020322: BeppoSAX/NFI Observations
  23. GRB 020321: Optical observations
  24. GRB 011121: Fourth Epoch of HST Imaging
  25. GRB020317: optical observations
  26. GRB020321 optical observations
  27. GRB020321: BeppoSAX/NFI Observations
  28. GRB020305: NIR observations
  29. GRB 020317 : KISO Optical Observations
  30. GRB 020305: Optical Observations
  31. GRB020317, optical observations
  32. GRB 020317: Optical observations
  33. GRB 011121: Third HST Epoch
  34. GRB 011121: HST Observations reveal an intermediate-time multicolor
  35. GRB011121, possible supernova association
  36. GRB011130 (XRF011130) Second Epoch Chandra Observations
  37. GRB020305: Subaru Optical Observations
  38. GRB 020305: Optical observations
  39. XRF/GRB 011030 Images
  40. XRF/GRB 011030: Detection of the Probable Host Galaxy
  41. GRB 020305: Candidate optical afterglow
  42. Type Ic SN2002bl (SN/GRB?) Radio Observations
  43. GRB020305, optical observations
  44. GRB020305: Optical Observations
  45. GRB 020305: Optical observations
  46. HST Imaging of the afterglow and host of GRB 011121
  47. GRB 010921: HST Observations
  48. GRB020127: Further VLA Observations of Possible Counterparts
  49. RXTE Observations of SGR 1900+14
  50. GRB020127: Palomar and VLA Observations of Possible Counterparts
  51. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  52. SN2002ap (SN/GRB?) Echelle spectra
  53. SN2002ap (SN/GRB?) optical spectrographic observations
  54. GRB020127, WSRT radio observations
  55. GRB020127 Optical Observations
  56. SN 2002ap in M74
  57. SN2002ap (SN/GRB?) UBVRI Field Photometry
  58. GRB020127: Chandra Observations and Prospective Counterparts
  59. pre-SN2002ap (SN/GRB?) imaging of M74
  60. Type Ib/c SN2002ap (SN/GRB?)
  61. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  62. GRB020124, optical observations
  63. GRB020127: Optical observations
  64. GRB 020127, I-band observations starting 3.14-hr after the event
  65. GRB020127 Optical Observations -- Erratum to GCN 1230
  66. GRB010921 Optical Observations
  67. GRB020124: Optical observations
  68. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  69. GRB020124: Optical observations
  70. GRB 020124: Optical observations
  71. GRB 020124 Optical Observations
  72. IPN observations of SGR1806-20
  73. GRB 020124: Optical afterglow
  74. HETE 1896: Optical observations
  75. GRB optical counterpart candidate in GCN 1217 is M dwarf
  76. Possible optical counterpart to a GRB
  77. GRB011212, Optical Observations
  78. Optical polarization observations for GRB011211
  79. GRB 011211: Detection of the Probable Host Galaxy
  80. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  81. Color indices of the afterglow of GRB011211
  82. GRB011212: Optical observations at Gunma
  83. GRB 011130: Optical Observations of X-ray and Radio Sources
  84. GRB 011130, Radio/X-ray Comparison
  85. GRB011212: Optical observations
  86. GRB 011212: optical observation at Asiago
  87. GRB 011211: TNG Spectroscopic Observations
  88. GRB 011211, Optical Observations
  89. GRB011212: Optical observations
  90. GRB 011211 Optical Observations: Likely Afterglow
  91. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  92. GRB 011130: Optical Observations of Chandra Sources
  93. GRB 011130: Optical Observations of Chandra sources
  94. GRB011130 (XRF011130) Chandra Observations
  95. GRB 011130: Magellan spectroscopy
  96. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  97. GRB011130, optical observations
  98. GRB 011130, K band observations
  99. GRB011130, optical observations
  100. GRB011130 (XRF011130) optical observations

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