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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"

25101 results found.

  1. GRB 030328: optical observations
  2. GRB 030329: Optical afterglow fading
  3. GRB 030328: OT photometry
  4. GRB030328: optical spectroscopy at TNG
  5. GRB030328: optical photometry at the TNG
  6. VLT spectra of GRB 030328
  7. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  8. GRB 030328: Optical observations
  9. GRB030324 optical observation
  10. GRB030131, BVRcIc field photometry
  11. Possible GRB030323 localized by INTEGRAL
  12. GRB030323: Detection on 2003/03/24
  13. IPN triangulation of GRB030326 (single small error box)
  14. IPN triangulation of GRB030325 (two small error boxes)
  15. GRB030323: V, R, I photometry
  16. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  17. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  18. VLT/FORS2 spectra of GRB 030323
  19. GRB030323, optical observations
  20. GRB030324, BVRcIc field photometry
  21. GRB030323, BVRcIc field calibration
  22. IPN triangulation of GRB030320 (small error box)
  23. Possible GRB 030320 localized by INTEGRAL
  24. IPN triangulation of GRB030306 (single small error box - REVISED)
  25. IPN triangulation of GRB030306 (single small error box)
  26. IPN triangulation of GRB030306 (two small error boxes)
  27. GRB030226, BVRc observations
  28. Chandra detection of the X-ray afterglow of GRB 030226
  29. GRB030227: Kiso optical upper limit
  30. GRB030227, BVRcIc field photometry
  31. GRB030226, BVRcIc field calibration
  32. GRB 030228, optical observations
  33. GRB 030227: Confirmed Optical Afterglow (S1-A)
  34. GRB 030227: fading of candidate optical afterglow 'S1-A'
  35. GRB030227:Optical observations
  36. GRB 030227, possible optical counterpart of XMM-Newton source
  37. GRB030227 - faint tentative OT candidate
  38. GRB 030226, optical observations
  39. XMM-Newton observation of GRB030227
  40. GRB030227: Kiso optical observations
  41. GRB 030227: Kyoto optical observation
  42. GRB 030226, optical light curve
  43. GRB030227 localized by INTEGRAL
  44. GRB 030226 : Predicted light curve
  45. GRB030226: ESI spectroscopy
  46. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  47. GRB 030226 simultaneous optical observations
  48. GRB 030226, optical observations
  49. GRB030226: Optical decay index
  50. GRB 030226 Optical Spectra and R,I,z' Imaging
  51. GRB: Non-Referencing of GCN Circulars.
  52. IPN triangulation of GRB030217 (small error box)
  53. GRB 030131: marginal optical detection
  54. GRB 030204: Optical Observations
  55. GRB030204 field photometry
  56. GRB020819: Kiso R and I band observations
  57. GRB030131: Candidate Optical Afterglow
  58. IPN triangulation of GRB030204 (small error box)
  59. GRB 030131, optical observations
  60. GRB 030131: afterglow candidate
  61. GRB 030115, late-time optical observations
  62. GRB030131: corrected INTEGRAL position
  63. GRB 020819: Host galaxy at Radio Position
  64. IPN triangulation of GRB030131
  65. GRB 030131 optical observations
  66. GRB 030131 optical observations
  67. A long GRB detected by INTEGRAL
  68. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  69. GRB 030115, simultaneous observations by BOOTES-1
  70. GRB 030115: IR observations with IRSF/SIRIUS
  71. IPN triangulation of GRB030115C (large error box)
  72. GRB030115, afterglow candidate
  73. GRB 021211: R-band observations at late-time
  74. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  75. GRB 030115 : Possible IR counterpart
  76. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  77. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  78. GRB 030115: APO Optical Observations
  79. Information about where HETE will be pointing
  80. VLT spectroscopy of the probable host of GRB 021211
  81. IPN triangulation of GRB030101 (two large error boxes)
  82. GRB 021211: Probable Host and Underlying Supernova
  83. GRB 021112: Evidence for Another Dark Optical Afterglow
  84. GRB 021219: OSN optical observations
  85. GRB021219, optical observations
  86. GRB021219, optical observation by MASTER
  87. VLT spectra of GRB 021211 revisited
  88. GRB021219: a long GRB localized by INTEGRAL
  89. GRB021211: APO optical observations
  90. XRF 020903 : HST observations
  91. GRB 021201: Optical Observations
  92. GRB 021211: CTIO observations
  93. GRB021211, BVRI field photometry
  94. GRB021211: Optical observations in CrAO
  95. GRB 021211, optical observations
  96. GRB021211: Kiso Observations
  97. GRB 021201, optical observations
  98. GRB021211: Optical observations
  99. GRB 021201 (short/hard), NOT observations
  100. SUB-MM SEARCH FOR GRB 021211

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