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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').
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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"

45470 results found.

  1. GRB 040912: Optical Observations
  2. GRB/XRF040912,optical observations
  3. GRB 040912, BVRI observations
  4. Optical observations of GRB/XRF 040912 = HETE 3557
  5. An intense burst from SGR1806-20
  6. GRB040912 : Kiso Optical follow-up observation
  7. IBAS GRB Alerts 1978-1980
  8. Optical observations of field of GRB040912
  9. HETE 3557: Optical observations
  10. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  11. GRB 040827: XMM-Newton data
  12. GRB040903 - A XRF?
  13. GRB040827: analysis of the XMM-Newton observation
  14. GRB040903, REM near-IR observation
  15. GRB 040903 - INTEGRAL data analysis
  16. IBAS Alert 1974. Not a real GRB
  17. Very bright burst detected from SGR 1806-20
  18. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  19. Possible GRB 040903 - further analysis
  20. Possible GRB 040903 detected with INTEGRAL
  21. GRB 040827 - Radio Observations
  22. XMM-Newton Images of GRB 040827
  23. GRB040825A: Optical observations
  24. GRB040825A: Optical observations
  25. GRB 040827: optical and NIR observations at the VLT
  26. GRB 040827: UKIRT - 2nd epoch K-band imaging
  27. GRB 040827: 2nd epoch of Magellan K-band imaging
  28. GRB 040827: K imaging - no evidence of variability
  29. GRB 040827: Detection of NIR afterglow
  30. GRB 040827: Possible detection of optical afterglow
  31. GRB 040827: RTT150 optical observations
  32. GRB040827 XMM-Newton observation
  33. GRB040825A: optical limit before GRB
  34. MASTER: GRB040827 possible OT
  35. GRB 040825B: Optical observations
  36. GRB040827 optical observations
  37. GRB 040827 : Planned XMM-Newton observation
  38. GRB 040827 - Refined position
  39. GRB 040827 - A long GRB detected by INTEGRAL
  40. GRB040825B, BVRcIc field photometry
  41. GRB040825A, BVRcIc field photometry
  42. GCN GRB OBSERBATION REPORT
  43. GRB 040825A,optical observations
  44. Increase of SGR 1806-20 activity
  45. GRB040825A: optical observations
  46. GRB040825B: optical observations
  47. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  48. GRB 040825A: Optical observations.
  49. MASTER: GRB040825a optical observation
  50. MASTER: GRB040825b optical observation
  51. GRB040825B: Correction to GCN 2657
  52. GRB 040825: Optical observations
  53. XRF040812: possible afterglow second Chandra observation
  54. GRB 040812: Second epoch CXO Observations
  55. GRB040823,optical observation
  56. XRF040812: GMRT observations
  57. Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F)
  58. XRF 040812: optical observation at VLT
  59. GRB 040812: Optical counterparts of CXO sources
  60. XRF040812: possible afterglow
  61. CXO observation of GRB 040812
  62. Bursting activity from SGR 1806-20 detected with IBAS
  63. IPN/HETE localizations of GRB040810 (=H3489)
  64. GRB 040812: Keck and LCO optical observations
  65. GRB 040812: Keck and LCO observations
  66. GRB 040812: radio observations
  67. GRB040812, optical/IR observations
  68. Konus-Wind observation of GRB040810 (=H3489)
  69. GRB 040812: a long GRB detected by INTEGRAL
  70. GRB 040810: Optical observations of a limited region
  71. XRF040701: Optical Observations at ESO
  72. IPN/HETE triangulation of GRB040802 (=H3485)
  73. GRB 040730, infrared observations
  74. GRB 040730: Optical observations
  75. GRB 040730: a long GRB detected with INTEGRAL
  76. Ongoing activity of SGR 1806-20
  77. GRB040624: optical monitoring at TNG
  78. XRF 040701 - optical observations of the decaying Chandra source
  79. XRF040701: Second-Epoch Chandra Observations
  80. Cancellation of IBAS/INTEGRAL GRB alerts
  81. XRF040701: VLA Observations
  82. XRF040701: Magellan Spectroscopy of Chandra Source #2 Associated Galaxy
  83. XRF040701: First-Epoch Chandra Observations
  84. IBAS Alert 1836: NOT a real GRB
  85. GRB040709 J,H-band observations
  86. GRB040624, optical observations
  87. GRB040706:observation at University of Miyazaki
  88. XRF 040701, optical observations
  89. XRF040701 (=U11548): a bright XRF detected by HETE
  90. GRB 040624: optical observations
  91. Optical Observations of GRB040624
  92. GRB 040624: optical observations at TNG and VLT
  93. MASTER: GRB 040624 optical observation after 0,48d
  94. GRB 040624: R-band observations
  95. GRB 040624, optical observations
  96. GRB 040624 - A long GRB detected with INTEGRAL
  97. GRB 030329: Rebrightening of hyperluminal ejecta.
  98. IPN Summary of SGR1806-20 Activity in 2004
  99. GRB040511: Retraction of redshift identification
  100. SGR 1806-20: no IR variability of the proposed counterparts

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