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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"

24361 results found.

  1. GRB030329: ROTSE network observes steepening of decay curve
  2. GRB 030329: Optical decay and synthesis
  3. GRB030329: optical spectroscopy with the TNG
  4. GRB 030329: Upper limit from 5.6 hours before trigger
  5. GRB030328: X-ray Afterglow Observed with Chandra
  6. GRB030329:optical observations by MASTER
  7. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  8. GRB 030328: Optical observations
  9. GRB030328: optical spectroscopy at TNG
  10. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  11. GRB030324, optical observations
  12. GRB030324, optical observations
  13. GRB 030324: TAROT optical observations
  14. GRB030323: V, R, I photometry
  15. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  16. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  17. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  18. VLT/FORS2 spectra of GRB 030323
  19. IPN triangulation of GRB030320
  20. Possible GRB 030320 localized by INTEGRAL
  21. GRB030226, addendum to GCN 1892
  22. IPN upper limit to a GRB associated with SN2003L
  23. GRB030226: Optical observations at Asiago
  24. IPN triangulation of GRB030306 (two small error boxes)
  25. IPN triangulation of GRB030306 (intense; annulus only so far)
  26. GRB 030226: Optical observations
  27. GRB030226: Analysis of Chandra data
  28. GRB 030227: Optical observations
  29. GRB030226, BVRc observations
  30. Chandra detection of the X-ray afterglow of GRB 030226
  31. GRB 030226, further optical/NIR imaging
  32. GRB 030226: Ic Observations
  33. GRB030227: Kiso optical upper limit
  34. GRB 030227 optical afterglow
  35. 030302: NOT A GRB
  36. 030228: NOT A GRB
  37. GRB 030226: Steep Decline
  38. GRB 030227: Confirmed Optical Afterglow (S1-A)
  39. GRB 030226: Optical observations
  40. GRB030227:Optical observations
  41. GRB 030227, possible optical counterpart of XMM-Newton source
  42. GRB030227: Kiso optical observations
  43. GRB 030226, optical light curve
  44. GRB030227: refined INTEGRAL position
  45. GRB030227 localized by INTEGRAL
  46. Possible break in the GRB 030226 light curve
  47. GRB 030226 : Predicted light curve
  48. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  49. GRB 030226 simultaneous optical observations
  50. Two absorption systems in GRB 030226
  51. GRB 030226 Optical Spectra and R,I,z' Imaging
  52. GRB: Non-Referencing of GCN Circulars.
  53. GRB 030131: marginal optical detection
  54. GRB 030204: Optical Observations
  55. GRB030131: Candidate Optical Afterglow
  56. GRB 030204, optical observations
  57. GRB 030131, optical observations
  58. GRB030131: Kiso optical limit for corrected position
  59. GRB030131: Optical limits for corrected position
  60. GRB 030115, late-time optical observations
  61. GRB030131: corrected INTEGRAL position
  62. GRB030131: Kiso Observations
  63. GRB 020819: Host galaxy at Radio Position
  64. IPN triangulation of GRB030131
  65. GRB030131: Optical limit
  66. GRB030131: refined position
  67. A long GRB detected by INTEGRAL
  68. IPN triangulation of GRB030119 (two large error boxes)
  69. IPN triangulation of GRB030117 (two large error boxes)
  70. Publicizing GRB Discoveries - A Message from NASA HQ
  71. GRB 030115, simultaneous observations by BOOTES-1
  72. GRB030115: R-band counterpart of IR candidate
  73. GRB 021211: R-band observations at late-time
  74. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  75. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  76. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  77. GRB 021211: VLT spectrum
  78. Information about where HETE will be pointing
  79. IPN triangulation of GRB030105 (large error box)
  80. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  81. VLT spectroscopy of the probable host of GRB 021211
  82. IPN triangulation of GRB030101 (two large error boxes)
  83. GRB021219, optical observations
  84. GRB021219, optical observation by MASTER
  85. XRF 020903 : HST observations
  86. GRB 021211: CTIO observations
  87. GRB021211: Measurement of Early Time Afterglow
  88. VLT spectrum of GRB 021211
  89. IPN triangulation of GRB021211B (two large error boxes)
  90. GRB 021211: early break in light curve
  91. GRB021204: Kiso Observations
  92. GRB 021211, R- and I-band observations
  93. GRB021211, OT at 108 s
  94. GRB021211 (HETE2493), OT at 143 sec
  95. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  96. GRB 021204: Optical Observations at RIKEN
  97. IPN detection of renewed activity from SGR1806-20
  98. GRB 021201: BOOTES simultaneous optical observations
  99. Radio Catalog of GRB Afterglows
  100. GRB021004, late time optical observations

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