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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"

20966 results found.

  1. GRB 030204, optical observations
  2. GRB 030131, optical observations
  3. GRB030131: Optical limits for corrected position
  4. GRB 030115, late-time optical observations
  5. GRB030131: Kiso Observations
  6. GRB 020819: Host galaxy at Radio Position
  7. GRB 020819: afterglow candidate
  8. GRB030131: Optical limit
  9. GRB 030131 optical observations
  10. GRB 030131 optical observations
  11. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  12. Type Ic SN2003L (SN/GRB?) Radio Observations
  13. GRB030115 submm upper limit
  14. GRB 030115: Further IR observations with IRSF/SIRIUS
  15. GRB 030115: Radio detection of IR candidate
  16. GRB 030115, simultaneous observations by BOOTES-1
  17. GRB 030115: IR observations with IRSF/SIRIUS
  18. GRB 021211: R-band observations at late-time
  19. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  20. GRB 030115 : Possible IR counterpart
  21. GRB 030115: Radio Observations
  22. GRB030115: R-band observations at Asiago
  23. GRB030115: TAROT optical observations
  24. GRB 030115: APO Optical Observations
  25. GRB 030115, no optical candidate
  26. GRB 030115, optical observations
  27. GRB 030115, optical candidate
  28. Information about where HETE will be pointing
  29. VLT spectroscopy of the probable host of GRB 021211
  30. GRB 021211: Probable Host and Underlying Supernova
  31. GRB021211, radio observations
  32. GRB 021219: OSN optical observations
  33. GRB021219: Radio Observations
  34. GRB021219, optical observations
  35. IPN triangulation of GRB021219
  36. VLT spectra of GRB 021211 revisited
  37. GRB021211: APO optical observations
  38. IPN detection of continued activity from SGR1806-20
  39. XRF 020903 : HST observations
  40. GRB 021201: Optical Observations
  41. GRB 021211, optical observations
  42. GRB 021211: CTIO observations
  43. GRB 021211: early break in light curve
  44. GRB021211: Optical observations in CrAO
  45. GRB 021211, IR observations
  46. GRB 021211, optical observations
  47. GRB 021211: Optical Observations
  48. GRB021211: Kiso Observations
  49. GRB021204: Kiso Observations
  50. GRB 021201, optical observations
  51. GRB 021211: Radio Observations
  52. GRB021211: Optical observations
  53. GRB 021201 (short/hard), NOT observations
  54. SUB-MM SEARCH FOR GRB 021211
  55. GRB 021211 Milagro GeV/TeV Observations
  56. GRB 021211, R- and I-band observations
  57. GRB021211 - Upper limits from recent and historical observations
  58. GRB021211, OT at 108 s
  59. GRB 021204: I-band Observations
  60. HETE 2493: Optical observations
  61. HETE 2493: Optical observations
  62. HETE 2493: Optical candidate
  63. GRB 021204: Optical Observations at RIKEN
  64. GRB 021125: Radio Observations
  65. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  66. GRB 021201, Radio Observations
  67. GRB 021201: Optical Observations
  68. GRB 021201: BOOTES simultaneous optical observations
  69. GRB021004, late time optical observations
  70. IPN detection of continued SGR1900+14 activity
  71. GRB021113, SPI ACS observation
  72. GRB021113: optical observations at Bisei
  73. GRB 021113: Evidence for a Dark Optical Afterglow
  74. GRB 021112, Radio Observations
  75. GRB 021112: Variable Source in R-band search
  76. GRB021112: Optical Observations
  77. GRB021113: Kiso Observations
  78. GRB 021113: Optical observations
  79. GRB 021112: RAPTOR Observations
  80. GRB 021113: Optical Observations
  81. GRB 021113: Optical Observations
  82. GRB 021112: Optical Observations
  83. GRB 021112: R-band search
  84. GRB 021016: Optical Observations
  85. GRB021004: Near infrared spectroscopy
  86. GRB021104: Optical Observations
  87. GRB021104: Optical observations
  88. GRB021104: optical observations
  89. Detection of activity from SGR 1900+14 with the RXTE/PCA
  90. GRB021004, late-time optical observations
  91. GRB 021004: optical observations
  92. GRB021004: Optical Observations
  93. GRB 020813; likely host galaxy.
  94. GRB 021008, radio observations
  95. GRB 021016, optical observations
  96. GRB 021004: VRI observations at TNG: possible break
  97. GRB021016, optical observations
  98. GRB 021008, optical observations
  99. GRB021004: Optical Observations
  100. GRB021004: High-resolution optical spectroscopy

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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