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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"

21769 results found.

  1. GRB040924,optical observation
  2. GRB040924,optical observation
  3. GRB040924: KAIT observations
  4. GRB 040924: Subaru NIR observation
  5. GRB 040924, optical follow-up
  6. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  7. XRF040916: continuing decay of OT
  8. TAROT Observations of GRB 040916 (HETE #3558)
  9. GRB040912(=H3557): Candidate Optical Afterglow
  10. XRF040916, optical observations
  11. XRF 040912, identification of CXO sources
  12. XRF 040912 (=H3557): Spectral and Temporal Properties
  13. XRF040912, BVRcIc field calibration
  14. XRF040916, BVRcIc field calibration
  15. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  16. GRB040916: Optical observations
  17. GRB 040912: Optical Observations
  18. GRB/XRF040912,optical observations
  19. GRB 040912, BVRI observations
  20. An intense burst from SGR1806-20
  21. GRB040912 : Kiso Optical follow-up observation
  22. Optical observations of field of GRB040912
  23. HETE 3557: Optical observations
  24. GRB040903 - A XRF?
  25. GRB040827: analysis of the XMM-Newton observation
  26. GRB040903, REM near-IR observation
  27. Very bright burst detected from SGR 1806-20
  28. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  29. GRB 040827 - Radio Observations
  30. XMM-Newton Images of GRB 040827
  31. GRB 040827: optical and NIR observations at the VLT
  32. GRB 040827: RTT150 optical observations
  33. GRB040827 XMM-Newton observation
  34. MASTER: GRB040827 possible OT
  35. GRB 040825B: Optical observations
  36. GRB 040827 : Planned XMM-Newton observation
  37. GRB 040827 - Refined position
  38. GRB040825B, BVRcIc field photometry
  39. GRB040825A, BVRcIc field photometry
  40. GCN GRB OBSERBATION REPORT
  41. GRB 040825A,optical observations
  42. Increase of SGR 1806-20 activity
  43. GRB040825A: optical observations
  44. GRB040825B: optical observations
  45. GRB 040812: Second epoch CXO Observations
  46. GRB040823,optical observation
  47. XRF040812: GMRT observations
  48. XRF 040812: optical observation at VLT
  49. GRB 040812: Optical counterparts of CXO sources
  50. CXO observation of GRB 040812
  51. GRB040812, optical/IR observations
  52. Konus-Wind observation of GRB040810 (=H3489)
  53. XRF040701: Optical Observations at ESO
  54. GRB 040730, infrared observations
  55. Ongoing activity of SGR 1806-20
  56. GRB040624: optical monitoring at TNG
  57. XRF 040701 - optical observations of the decaying Chandra source
  58. XRF040701: Second-Epoch Chandra Observations
  59. XRF040701: VLA Observations
  60. XRF040701: First-Epoch Chandra Observations
  61. GRB040624, optical observations
  62. GRB040706:observation at University of Miyazaki
  63. Optical Observations of GRB040624
  64. GRB 040624: optical observations at TNG and VLT
  65. MASTER: GRB 040624 optical observation after 0,48d
  66. GRB 040624, optical observations
  67. GRB 030329: Rebrightening of hyperluminal ejecta.
  68. IPN Summary of SGR1806-20 Activity in 2004
  69. SGR 1806-20: no IR variability of the proposed counterparts
  70. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  71. GRB 040606: Optical observations
  72. MASTER: HETE Alert 3274 optical observation
  73. Activivty of SGR 1806-20
  74. IPN triangulation of an intense intermediate burst from SGR1806-20
  75. GRB 040511, very fast decay?
  76. GRB 030324: Detection and Color of Host Galaxy
  77. GRB 040511: NIR observations with REM
  78. GRB040511: Candidate optical/NIR afterglow
  79. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  80. GRB 040511: Second Epoch Optical Observations
  81. GRB 040511: Optical observations
  82. GRB 040511: Optical Observations
  83. GRB040511: Optical Observations
  84. GRB040511: Optical Observations
  85. GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
  86. GRB 040423 (=H3175): A Long GRB Localized by HETE
  87. GRB040422 : I-band follow-up observation at Lulin Observatory
  88. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  89. GRB040422, BVRcIc field calibration
  90. GRB 040422,optical observation
  91. GRB 040403, deep optical observations
  92. MASTER: HETE Alert 3163, 3167 technical optical observation
  93. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  94. GRB 040403: Optical observations
  95. GRB 040329: hard burst detected by Konus-Wind and Helicon - Coronas-F
  96. GRB040323: NIR Observations and Variable Object
  97. GRB 040323, a dark GRB ?
  98. short hard GRB 040322
  99. GRB040223, improved XMM position
  100. GRB 031203, possible supernova

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