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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"

18335 results found.

  1. GRB030329: final R-band light curve by MASTER
  2. GRB030329, new UBVRcIc field photometry
  3. GRB 030329 , SPM optical observations
  4. GRB030329: Optical observations at Teramo
  5. GRB 030329: Radio observations at GMRT
  6. GRB 030329: Additional Mt. Laguna Optical Observations
  7. GRB 030329: Observations with ANDICAM
  8. GRB 030329: optical observations
  9. GRB 030324: Optical and NIR Observations
  10. GRB030329: R band light curve by MASTER
  11. GRB030329 - Light curve flattening
  12. GRB 030324, optical search
  13. GRB030329 - near contemporaneous optical limits from CONCAM
  14. GRB 030329, optical observations
  15. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  16. GRB030329, BVRcIc field photometry
  17. GRB030329, SPM optical observations
  18. GRB030329 optical observations
  19. GRB 030329: Optical pre-Imaging
  20. GRB 030329: Upper limit from 5.6 hours before trigger
  21. GRB030328: X-ray Afterglow Observed with Chandra
  22. GRB 030329, R-band observations
  23. GRB030329: Upper limits from recent and historical observations.
  24. GRB 030329: Optical Afterglow Observations
  25. GRB 030329: precise position from Kyoto images
  26. GRB 030328: optical observations
  27. GRB 030329: Optical afterglow fading
  28. GRB 030328: OT photometry
  29. GRB030328: optical photometry at the TNG
  30. GRB 030328: Optical observations
  31. GRB 030328: Finding chart
  32. GRB 030328: Optical afterglow candidate
  33. GRB030324 optical observation
  34. GRB030131, BVRcIc field photometry
  35. Possible GRB030323 localized by INTEGRAL
  36. GRB030323: Detection on 2003/03/24
  37. IPN triangulation of GRB030325 (single small error box)
  38. IPN triangulation of GRB030325 (two small error boxes)
  39. GRB030323: V, R, I photometry
  40. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  41. VLT/FORS2 spectra of GRB 030323
  42. GRB030323, optical observations
  43. GRB030324, BVRcIc field photometry
  44. GRB030323, BVRcIc field calibration
  45. Possible GRB 030320 localized by INTEGRAL
  46. GRB030226, BVRc observations
  47. Chandra detection of the X-ray afterglow of GRB 030226
  48. GRB030227: Kiso optical upper limit
  49. GRB030227, BVRcIc field photometry
  50. GRB030226, BVRcIc field calibration
  51. GRB 030228, optical observations
  52. GRB 030227: Confirmed Optical Afterglow (S1-A)
  53. GRB 030226: Optical observations
  54. GRB 030227: fading of candidate optical afterglow 'S1-A'
  55. GRB030227:Optical observations
  56. GRB 20030226: Upper limits from recent and historical observations
  57. GRB 030227, possible optical counterpart of XMM-Newton source
  58. XMM-Newton observation of GRB030227
  59. GRB030227: Kiso optical observations
  60. GRB 030227: Kyoto optical observation
  61. GRB030227 localized by INTEGRAL
  62. GRB030226: ESI spectroscopy
  63. GRB 030226 simultaneous optical observations
  64. GRB 030226, optical observations
  65. GRB030226: Optical decay index
  66. GRB 030226: Optical afterglow
  67. GRB 030131: marginal optical detection
  68. GRB 030204: Optical Observations
  69. GRB030204 field photometry
  70. GRB020819: Kiso R and I band observations
  71. GRB030131: Candidate Optical Afterglow
  72. GRB 030131, optical observations
  73. GRB 030131: afterglow candidate
  74. GRB 030115, late-time optical observations
  75. GRB 020819: Host galaxy at Radio Position
  76. GRB 030131 optical observations
  77. GRB 030131 optical observations
  78. A long GRB detected by INTEGRAL
  79. GRB 030115, simultaneous observations by BOOTES-1
  80. GRB 030115: IR observations with IRSF/SIRIUS
  81. GRB030115, afterglow candidate
  82. GRB 021211: R-band observations at late-time
  83. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  84. GRB 030115 : Possible IR counterpart
  85. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  86. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  87. GRB 030115: APO Optical Observations
  88. VLT spectroscopy of the probable host of GRB 021211
  89. GRB 021211: Probable Host and Underlying Supernova
  90. GRB 021112: Evidence for Another Dark Optical Afterglow
  91. GRB 021219: OSN optical observations
  92. GRB021219, optical observations
  93. GRB021219, optical observation by MASTER
  94. GRB021219: a long GRB localized by INTEGRAL
  95. GRB021211: APO optical observations
  96. XRF 020903 : HST observations
  97. GRB 021201: Optical Observations
  98. GRB 021211: CTIO observations
  99. GRB021211, BVRI field photometry
  100. GRB021211: Optical observations in CrAO

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