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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"

28058 results found.

  1. GRB041006 (=HETE3570): optical observations
  2. ROTSE-IIIa Observations of GRB 041006
  3. GRB041006: MASTER optical observations
  4. GRB041006,optical observation
  5. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  6. GRB041006: Fading of optical afterglow candidate
  7. GRB 041006: Optical afterglow candidate
  8. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  9. XRF 020903: Observations of the Host Galaxy
  10. radio observations, GRB 040924
  11. GRB040929,optical observation
  12. GRB040924,optical observation
  13. GRB040924,optical observation
  14. GRB 040924: detection of possible host galaxy by Subaru
  15. GRB040924: KAIT observations
  16. GRB040924 : Optical candidate observations at Lulin observatory
  17. GRB040924 : Optical candidate observations at Lulin observatory
  18. GRB 040924: Subaru NIR observation
  19. XRF 040912: Radio Observations
  20. XRF 040916: Radio Observations
  21. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  22. XRF040916: continuing decay of OT
  23. TAROT Observations of GRB 040916 (HETE #3558)
  24. GRB040912(=H3557): Candidate Optical Afterglow
  25. XRF040916, optical observations
  26. XRF 040912, identification of CXO sources
  27. XRF040912, BVRcIc field calibration
  28. XRF040916, BVRcIc field calibration
  29. GRB040916: Archival optical observations
  30. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  31. GRB040916: Optical observations
  32. GRB040912 (= H3557): Chandra Observations Scheduled
  33. GRB 040912: Optical Observations
  34. GRB/XRF040912,optical observations
  35. GRB 040912, BVRI observations
  36. Optical observations of field of GRB040912
  37. HETE 3557: Optical observations
  38. GRB040903 - A XRF?
  39. GRB040827: analysis of the XMM-Newton observation
  40. GRB040903, REM near-IR observation
  41. Very bright burst detected from SGR 1806-20
  42. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  43. Possible GRB 040903 - further analysis
  44. GRB 040827 - Radio Observations
  45. XMM-Newton Images of GRB 040827
  46. GRB 040827: optical and NIR observations at the VLT
  47. GRB 040827: UKIRT - 2nd epoch K-band imaging
  48. GRB 040827: 2nd epoch of Magellan K-band imaging
  49. GRB 040827: K imaging - no evidence of variability
  50. GRB 040827: Detection of NIR afterglow
  51. GRB040827 XMM-Newton observation
  52. GRB040825A: optical limit before GRB
  53. GRB 040825B: Optical observations
  54. GRB 040827 : Planned XMM-Newton observation
  55. GRB040825B, BVRcIc field photometry
  56. GRB040825A, BVRcIc field photometry
  57. GCN GRB OBSERBATION REPORT
  58. GRB 040825A,optical observations
  59. GRB040825A: optical observations
  60. GRB040825B: optical observations
  61. MASTER: GRB040825b optical observation
  62. GRB 040825: Optical observations
  63. XRF040812: possible afterglow second Chandra observation
  64. GRB 040812: Second epoch CXO Observations
  65. GRB040823,optical observation
  66. XRF040812: GMRT observations
  67. XRF 040812: optical observation at VLT
  68. GRB 040812: Optical counterparts of CXO sources
  69. XRF040812: possible afterglow
  70. CXO observation of GRB 040812
  71. GRB 040812: radio observations
  72. GRB040812, optical/IR observations
  73. GRB 040812: a long GRB detected by INTEGRAL
  74. XRF040701: Optical Observations at ESO
  75. GRB 040730, infrared observations
  76. GRB 040730: a long GRB detected with INTEGRAL
  77. Ongoing activity of SGR 1806-20
  78. GRB040624: optical monitoring at TNG
  79. XRF 040701 - optical observations of the decaying Chandra source
  80. XRF040701: Second-Epoch Chandra Observations
  81. XRF040701: VLA Observations
  82. XRF040701: First-Epoch Chandra Observations
  83. GRB040624, optical observations
  84. GRB040706:observation at University of Miyazaki
  85. Optical Observations of GRB040624
  86. GRB 040624: optical observations at TNG and VLT
  87. MASTER: GRB 040624 optical observation after 0,48d
  88. GRB 040624, optical observations
  89. GRB 040624 - A long GRB detected with INTEGRAL
  90. GRB 030329: Rebrightening of hyperluminal ejecta.
  91. IPN Summary of SGR1806-20 Activity in 2004
  92. SGR 1806-20: no IR variability of the proposed counterparts
  93. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  94. SGR 1806-20, potential NIR counterpart
  95. GRB 040606: Optical observations
  96. MASTER: HETE Alert 3274 optical observation
  97. Activivty of SGR 1806-20
  98. GRB 040511, very fast decay?
  99. GRB 030324: Detection and Color of Host Galaxy
  100. GRB 040511: NIR observations with REM

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