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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"

24671 results found.

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

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