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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"

20514 results found.

  1. GRB030323: V, R, I photometry
  2. GRB 030324 (HETE #2641): Optical observations
  3. GRB030324, Optical Observations
  4. GRB030323: Upper limits from recent and historical observations.
  5. GRB030323, optical observations
  6. GRB030324, BVRcIc field photometry
  7. GRB030323, possible optical counterpart
  8. GRB030323, BVRcIc field calibration
  9. GRB 030324 optical observations
  10. GRB 030320: Optical Observations
  11. GRB 030324, optical observations
  12. GRB030226, addendum to GCN 1892
  13. GRB 030226 Optical observations
  14. GRB030226: Optical observations at Asiago
  15. GRB 030226: Optical observations
  16. GRB 030227: Optical observations
  17. GRB030226, BVRc observations
  18. GRB 030226, further optical/NIR imaging
  19. GRB030227, optical observations
  20. GRB 030226: Ic Observations
  21. GRB 030228, optical observations
  22. GRB 030226: Steep Decline
  23. GRB 030227: Confirmed Optical Afterglow (S1-A)
  24. GRB 030226: R band polarimetric observations
  25. GRB 030226: Optical observations
  26. GRB030227:Optical observations
  27. GRB 20030226: Upper limits from recent and historical observations
  28. GRB 030227, possible optical counterpart of XMM-Newton source
  29. GRB 030226, optical observations
  30. GRB030227: Kiso optical observations
  31. GRB 030226, optical light curve
  32. GRB030226: optical observation
  33. GRB030226: ESI spectroscopy
  34. GRB 030226 simultaneous optical observations
  35. GRB 030226, optical observations
  36. GRB030226: optical observations and refined redshift
  37. GRB030226: Optical decay index
  38. GRB 030226, optical observations
  39. GRB030226: Candidate optical afterglow
  40. GRB 030217: Optical Observations at 4, 5, and 6 Days
  41. GRB030217: optical observations
  42. GRB030115, WSRT radio observations - correction to GCN 1864
  43. GRB 030131: marginal optical detection
  44. GRB030115, WSRT radio observations
  45. GRB 030204: Optical Observations
  46. GRB020819: Kiso R and I band observations
  47. GRB030131: Candidate Optical Afterglow
  48. GRB 030115: Optical Observations
  49. GRB 030204, optical observations
  50. GRB 030131, optical observations
  51. GRB030131: Optical limits for corrected position
  52. GRB 030115, late-time optical observations
  53. GRB030131: Kiso Observations
  54. GRB 020819: Host galaxy at Radio Position
  55. GRB 020819: afterglow candidate
  56. GRB030131: Optical limit
  57. GRB 030131 optical observations
  58. GRB 030131 optical observations
  59. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  60. Type Ic SN2003L (SN/GRB?) Radio Observations
  61. GRB030115 submm upper limit
  62. GRB 030115: Further IR observations with IRSF/SIRIUS
  63. GRB 030115: Radio detection of IR candidate
  64. GRB 030115, simultaneous observations by BOOTES-1
  65. GRB 030115: IR observations with IRSF/SIRIUS
  66. GRB 021211: R-band observations at late-time
  67. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  68. GRB 030115 : Possible IR counterpart
  69. GRB 030115: Radio Observations
  70. GRB030115: R-band observations at Asiago
  71. GRB030115: TAROT optical observations
  72. GRB 030115: APO Optical Observations
  73. GRB 030115, no optical candidate
  74. GRB 030115, optical observations
  75. GRB 030115, optical candidate
  76. Information about where HETE will be pointing
  77. VLT spectroscopy of the probable host of GRB 021211
  78. GRB 021211: Probable Host and Underlying Supernova
  79. GRB021211, radio observations
  80. GRB 021219: OSN optical observations
  81. GRB021219: Radio Observations
  82. GRB021219, optical observations
  83. IPN triangulation of GRB021219
  84. VLT spectra of GRB 021211 revisited
  85. GRB021211: APO optical observations
  86. IPN detection of continued activity from SGR1806-20
  87. XRF 020903 : HST observations
  88. GRB 021201: Optical Observations
  89. GRB 021211, optical observations
  90. GRB 021211: CTIO observations
  91. GRB 021211: early break in light curve
  92. GRB021211: Optical observations in CrAO
  93. GRB 021211, IR observations
  94. GRB 021211, optical observations
  95. GRB 021211: Optical Observations
  96. GRB021211: Kiso Observations
  97. GRB021204: Kiso Observations
  98. GRB 021201, optical observations
  99. GRB 021211: Radio Observations
  100. GRB021211: Optical observations

Advanced

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