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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"

21263 results found.

  1. XRF040916: continuing decay of OT
  2. TAROT Observations of GRB 040916 (HETE #3558)
  3. GRB040912(=H3557): Candidate Optical Afterglow
  4. XRF040916, optical observations
  5. XRF 040912, identification of CXO sources
  6. XRF 040912 (=H3557): Spectral and Temporal Properties
  7. XRF040912, BVRcIc field calibration
  8. XRF040916, BVRcIc field calibration
  9. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  10. GRB040916: Optical observations
  11. GRB 040912: Optical Observations
  12. GRB/XRF040912,optical observations
  13. GRB 040912, BVRI observations
  14. An intense burst from SGR1806-20
  15. GRB040912 : Kiso Optical follow-up observation
  16. Optical observations of field of GRB040912
  17. HETE 3557: Optical observations
  18. GRB040903 - A XRF?
  19. GRB040827: analysis of the XMM-Newton observation
  20. GRB040903, REM near-IR observation
  21. Very bright burst detected from SGR 1806-20
  22. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  23. GRB 040827 - Radio Observations
  24. XMM-Newton Images of GRB 040827
  25. GRB 040827: optical and NIR observations at the VLT
  26. GRB 040827: RTT150 optical observations
  27. GRB040827 XMM-Newton observation
  28. MASTER: GRB040827 possible OT
  29. GRB 040825B: Optical observations
  30. GRB 040827 : Planned XMM-Newton observation
  31. GRB 040827 - Refined position
  32. GRB040825B, BVRcIc field photometry
  33. GRB040825A, BVRcIc field photometry
  34. GCN GRB OBSERBATION REPORT
  35. GRB 040825A,optical observations
  36. Increase of SGR 1806-20 activity
  37. GRB040825A: optical observations
  38. GRB040825B: optical observations
  39. GRB 040812: Second epoch CXO Observations
  40. GRB040823,optical observation
  41. XRF040812: GMRT observations
  42. XRF 040812: optical observation at VLT
  43. GRB 040812: Optical counterparts of CXO sources
  44. CXO observation of GRB 040812
  45. GRB040812, optical/IR observations
  46. Konus-Wind observation of GRB040810 (=H3489)
  47. XRF040701: Optical Observations at ESO
  48. GRB 040730, infrared observations
  49. Ongoing activity of SGR 1806-20
  50. GRB040624: optical monitoring at TNG
  51. XRF 040701 - optical observations of the decaying Chandra source
  52. XRF040701: Second-Epoch Chandra Observations
  53. XRF040701: VLA Observations
  54. XRF040701: First-Epoch Chandra Observations
  55. GRB040624, optical observations
  56. GRB040706:observation at University of Miyazaki
  57. Optical Observations of GRB040624
  58. GRB 040624: optical observations at TNG and VLT
  59. MASTER: GRB 040624 optical observation after 0,48d
  60. GRB 040624, optical observations
  61. GRB 030329: Rebrightening of hyperluminal ejecta.
  62. IPN Summary of SGR1806-20 Activity in 2004
  63. SGR 1806-20: no IR variability of the proposed counterparts
  64. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  65. GRB 040606: Optical observations
  66. MASTER: HETE Alert 3274 optical observation
  67. Activivty of SGR 1806-20
  68. IPN triangulation of an intense intermediate burst from SGR1806-20
  69. GRB 040511, very fast decay?
  70. GRB 030324: Detection and Color of Host Galaxy
  71. GRB 040511: NIR observations with REM
  72. GRB040511: Candidate optical/NIR afterglow
  73. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  74. GRB 040511: Second Epoch Optical Observations
  75. GRB 040511: Optical observations
  76. GRB 040511: Optical Observations
  77. GRB040511: Optical Observations
  78. GRB040511: Optical Observations
  79. GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
  80. GRB 040423 (=H3175): A Long GRB Localized by HETE
  81. GRB040422 : I-band follow-up observation at Lulin Observatory
  82. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  83. GRB040422, BVRcIc field calibration
  84. GRB 040422,optical observation
  85. GRB 040403, deep optical observations
  86. MASTER: HETE Alert 3163, 3167 technical optical observation
  87. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  88. GRB 040403: Optical observations
  89. GRB 040329: hard burst detected by Konus-Wind and Helicon - Coronas-F
  90. GRB040323: NIR Observations and Variable Object
  91. GRB 040323, a dark GRB ?
  92. short hard GRB 040322
  93. GRB040223, improved XMM position
  94. GRB 031203, possible supernova
  95. MASTER: RXTE GRB040308 optical observation
  96. IBAS results on a burst from SGR1806-20
  97. IPN triangulation of GRB040228 (H3066, H3067)
  98. GRB040228 : KISO optical follow-up observation
  99. GRB 040223: Deep NIR NTT observations
  100. GRB 040223 : Optical observation (non-detection)

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