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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"

26362 results found.

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

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