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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"

41220 results found.

  1. GRB 041211: Optical follow-up in East Asian region
  2. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  3. GRB041211: P60 optical imaging
  4. GRB970815: Discovery of Optical Afterglow
  5. Triangulation of short GRB 041116 (large error box)
  6. GRB041015: Near-Infrared observations
  7. GRB 040924: Afterglow Color
  8. GRB 041006: GETS Optical Afterglow Observation
  9. Summary of the recent bursts from SGR 1806-20
  10. GRB 041006: Optical Observations
  11. GRB041006, late-time optical photometry
  12. GRB041015, optical observation in CrAO
  13. GRB041006: RTT150 Optical Observations
  14. GRB041015 : Multi epoch optical observations
  15. GRB 041016: BOOTES-2 simultaneous observation
  16. GRB041006: RTT150 Optical Observations
  17. GRB041016,optical observation
  18. GRB 041016: Optical limits
  19. GRB 041016: Optical limits in V, R, I
  20. GRB 041016:Optical limit during first minute
  21. GRB041016: MASTER: Optical observations
  22. GRB 041015: Optical Observations at Rikubetsu
  23. GRB041006: Near Infrared observations
  24. GRB 041016: Optical limit
  25. GRB 041015 R band observations
  26. GRB040924, BVRcIc field calibration
  27. GRB041015: MASTER: Optical observations
  28. GRB041015,optical observation
  29. GRB041006: Fading X-ray Afterglow Observed with Chandra
  30. GRB 041015: Optical limit at Osaka University
  31. GRB041015 : Optical follow-up at Kiso
  32. GRB 041015 - A long GRB detected by INTEGRAL
  33. GRB 041006 R observations in Loiano
  34. GRB041006: VLT observations of the afterglow and host galaxy
  35. GRB041006: Optical observations and Potential host galaxy
  36. GRB041006, BVRcIc field calibration
  37. GRB 040924: VLT spectroscopy
  38. GRB 041006: SARA afterglow observations
  39. GRB041006, optical observation in CrAO
  40. Search for SN light in XRF 040912 with MEGACAM
  41. GRB 040916: Afterglow Color at Early Times
  42. GRB 041006 Optical afterglow observations
  43. IBAS GRB Alert # 2010
  44. GRB 041006: BR observations with VATT
  45. GRB 041006: Redshift confirmed
  46. GRB041006: Liverpool Telescope optical observations
  47. GRB041006: break in the light curve
  48. GRB 041006: Radio Observations
  49. GRB041006, further submilllimetre observations
  50. GRB 041006 : optical follow-up observation at Lulin Observatory
  51. GRB 041006 : Optical follow-up observation at TAROT
  52. GRB041006: Optical photometry and spectroscopy at TNG
  53. GRB 041006: presice astrometry
  54. GRB 041006 : optical observation at Bisei
  55. GRB041006, optical I observation
  56. GRB041006 (=HETE3570): optical observations
  57. ROTSE-IIIa Observations of GRB 041006
  58. GRB041006, optical observation
  59. GRB041006, submillimetre observations
  60. GRB041006: MASTER optical observations
  61. GRB041006,optical observation
  62. GRB 041006: Optical decay
  63. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  64. GRB041006: Fading of optical afterglow candidate
  65. GRB 041006 : Optical follow-up observation at KISO
  66. GRB 041006: Finding chart
  67. GRB 041006: Optical afterglow candidate
  68. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  69. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  70. XRF 020903: Observations of the Host Galaxy
  71. SGR 1806-20 still active
  72. GRB 040924: Second Epoch WSRT Radio Observations
  73. radio observations, GRB 040924
  74. GRB040929,optical observation
  75. GRB040929: MASTER optical observations
  76. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  77. GRB040924,optical observation
  78. GRB040924, RTT150 optical observation
  79. GRB040924,optical observation
  80. GRB 040924: detection of possible host galaxy by Subaru
  81. GRB040924, RTT150 optical observation
  82. GRB040924: KAIT observations
  83. GRB040924: Afterglow magnitude at t=17.5hr
  84. GRB 040924: WSRT Radio Observations
  85. GRB040924 : Optical candidate observations at Lulin observatory
  86. GRB040924 : Optical candidate observations at Lulin observatory
  87. GRB 040924: Subaru NIR observation
  88. GRB040924: Optical afterglow properties
  89. GRB 040924: RTT150 optical observations
  90. GRB 040924, optical follow-up
  91. GRB040924: MASTER: OT decay
  92. GRB040924: MASTER Optical observations
  93. IPN triangulation of GRB040924 (H3564)
  94. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  95. GRB040924 (H3564): Optical afterglow candidate
  96. XRF 040912: Radio Observations
  97. XRF 040916: Radio Observations
  98. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  99. XRF040916: continuing decay of OT
  100. GRB040912(=H3557): Candidate Optical Afterglow

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