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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"

20963 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. Optical observations of field of GRB040912
  6. HETE 3557: Optical observations
  7. GRB 040827 - Radio Observations
  8. GRB040825A: Optical observations
  9. GRB040825A: Optical observations
  10. GRB 040827: optical and NIR observations at the VLT
  11. GRB 040827: 2nd epoch of Magellan K-band imaging
  12. GRB 040827: Detection of NIR afterglow
  13. GRB 040827: Possible detection of optical afterglow
  14. GRB 040827: RTT150 optical observations
  15. GRB 040825B: Optical observations
  16. GRB040827 optical observations
  17. GRB 040825A,optical observations
  18. GRB040825A: optical observations
  19. GRB040825B: optical observations
  20. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  21. GRB 040825A: Optical observations.
  22. GRB040825B: Correction to GCN 2657
  23. GRB 040825: Optical observations
  24. GRB 040812: Second epoch CXO Observations
  25. XRF040812: GMRT observations
  26. XRF 040812: optical observation at VLT
  27. GRB 040812: Optical counterparts of CXO sources
  28. GRB 040812: Keck and LCO optical observations
  29. GRB 040812: Keck and LCO observations
  30. GRB 040812: radio observations
  31. GRB040812, optical/IR observations
  32. GRB 040810: Optical observations of a limited region
  33. XRF040701: Optical Observations at ESO
  34. GRB 040730, infrared observations
  35. GRB 040730: Optical observations
  36. GRB040624: optical monitoring at TNG
  37. XRF 040701 - optical observations of the decaying Chandra source
  38. XRF040701: Second-Epoch Chandra Observations
  39. XRF040701: VLA Observations
  40. XRF040701: Magellan Spectroscopy of Chandra Source #2 Associated Galaxy
  41. XRF040701: First-Epoch Chandra Observations
  42. GRB040709 J,H-band observations
  43. GRB040624, optical observations
  44. XRF 040701, optical observations
  45. GRB 040624: optical observations
  46. Optical Observations of GRB040624
  47. GRB 040624: optical observations at TNG and VLT
  48. GRB 040624: R-band observations
  49. GRB 040624, optical observations
  50. GRB 030329: Rebrightening of hyperluminal ejecta.
  51. GRB040511: Retraction of redshift identification
  52. SGR 1806-20: no IR variability of the proposed counterparts
  53. SGR 1806-20, potential NIR counterpart
  54. GRB 040606: Optical observations
  55. GRB 040511: NIR observations with REM
  56. GRB 040511: Second Epoch Optical Observations
  57. GRB 040511: Optical observations
  58. GRB 040511: Optical Observations
  59. GRB040511: Optical Observations
  60. GRB040511: Optical Observations
  61. GRB040422: optical observations at Xinglong Observatory
  62. GRB040422: optical observations at CrAO
  63. GRB040422, optical observations at Loiano
  64. GRB040422: optical and NIR observations at the VLT
  65. GRB 040403, deep optical observations
  66. GRB 040403: Optical Observations
  67. GRB 040403 Optical Observations
  68. GRB 040403: Optical observations
  69. GRB 040403: optical observations
  70. GRB 040403: Optical Observations
  71. GRB040323: NIR Observations and Variable Object
  72. GRB 040228 Optical observations
  73. GRB 040223: Deep NIR NTT observations
  74. GRB 040223 : Optical observation (non-detection)
  75. GRB 040223, VLA observations
  76. GRB 040223: REM IJK Observations
  77. GRB031111, optical observations
  78. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  79. GRB031203: Chandra Observations
  80. GRB040106, follow-up radio observations
  81. GRB040106, Radio Observations
  82. GRB040106, likely optical afterglow
  83. GRB040106: Second Epoch Optical Observations
  84. GRB 031220: Optical observations of Chandra X-ray sources
  85. GRB040106: optical observations with REM+ROSS
  86. GRB 040106: Optical observations
  87. GRB031220: Palomar Observations
  88. GRB 031203 I-band monitoring
  89. GRB 2974 follow-up observations
  90. GRB 031203: SMARTS optical monitoring
  91. XMM-Newton Observations of GRB031203: Preliminary Images
  92. GRB 031203: Variable Radio Source
  93. GRB 031203: Magellan spectrum of possible GRB host
  94. GRB 031203: Deep NIR NTT & VLT observations
  95. GRB 031203: Radio detection
  96. GRB 031203: Further reports on December 4 observations
  97. GRB 031203: IR NTTobservations do not confirm REM detection
  98. GRB 031203: Apparent Spectral Break
  99. GRB 031203: IR REM Observations
  100. GRB031203: Optical Observations

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