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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"

16236 results found.

  1. SDSS 0.5m PT observations of GRB030329
  2. GRB030329: final R-band light curve by MASTER
  3. GRB030329, new UBVRcIc field photometry
  4. GRB 030329 , SPM optical observations
  5. GRB030329: Optical observations at Teramo
  6. GRB 030329: Radio observations at GMRT
  7. GRB 030329: Additional Mt. Laguna Optical Observations
  8. GRB 030329: Observations with ANDICAM
  9. GRB 030329: optical observations
  10. GRB 030324: Optical and NIR Observations
  11. GRB030329: R band light curve by MASTER
  12. GRB030329 - Light curve flattening
  13. GRB 030324, optical search
  14. GRB030329 - near contemporaneous optical limits from CONCAM
  15. GRB 030329, optical observations
  16. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  17. GRB030329, BVRcIc field photometry
  18. GRB030329, SPM optical observations
  19. GRB030329 optical observations
  20. GRB 030329: Optical pre-Imaging
  21. GRB 030329: Upper limit from 5.6 hours before trigger
  22. GRB030328: X-ray Afterglow Observed with Chandra
  23. GRB 030329, R-band observations
  24. GRB030329: Upper limits from recent and historical observations.
  25. GRB 030329: Optical Afterglow Observations
  26. GRB 030329: precise position from Kyoto images
  27. GRB 030328: optical observations
  28. GRB 030329: Optical afterglow fading
  29. GRB 030328: OT photometry
  30. GRB030328: optical photometry at the TNG
  31. GRB 030328: Optical observations
  32. GRB 030328: Finding chart
  33. GRB 030328: Optical afterglow candidate
  34. GRB030324 optical observation
  35. GRB030131, BVRcIc field photometry
  36. Possible GRB030323 localized by INTEGRAL
  37. GRB030323: Detection on 2003/03/24
  38. IPN triangulation of GRB030325 (single small error box)
  39. IPN triangulation of GRB030325 (two small error boxes)
  40. GRB030323: V, R, I photometry
  41. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  42. VLT/FORS2 spectra of GRB 030323
  43. GRB030323, optical observations
  44. GRB030324, BVRcIc field photometry
  45. GRB030323, BVRcIc field calibration
  46. Possible GRB 030320 localized by INTEGRAL
  47. GRB030226, BVRc observations
  48. Chandra detection of the X-ray afterglow of GRB 030226
  49. GRB030227: Kiso optical upper limit
  50. GRB030227, BVRcIc field photometry
  51. GRB030226, BVRcIc field calibration
  52. GRB 030228, optical observations
  53. GRB 030227: Confirmed Optical Afterglow (S1-A)
  54. GRB 030226: Optical observations
  55. GRB 030227: fading of candidate optical afterglow 'S1-A'
  56. GRB030227:Optical observations
  57. GRB 20030226: Upper limits from recent and historical observations
  58. GRB 030227, possible optical counterpart of XMM-Newton source
  59. XMM-Newton observation of GRB030227
  60. GRB030227: Kiso optical observations
  61. GRB 030227: Kyoto optical observation
  62. GRB030227 localized by INTEGRAL
  63. GRB030226: ESI spectroscopy
  64. GRB 030226 simultaneous optical observations
  65. GRB 030226, optical observations
  66. GRB030226: Optical decay index
  67. GRB 030226: Optical afterglow
  68. GRB 030131: marginal optical detection
  69. GRB 030204: Optical Observations
  70. GRB030204 field photometry
  71. GRB020819: Kiso R and I band observations
  72. GRB030131: Candidate Optical Afterglow
  73. GRB 030131, optical observations
  74. GRB 030131: afterglow candidate
  75. GRB 030115, late-time optical observations
  76. GRB 020819: Host galaxy at Radio Position
  77. GRB 030131 optical observations
  78. GRB 030131 optical observations
  79. A long GRB detected by INTEGRAL
  80. GRB 030115, simultaneous observations by BOOTES-1
  81. GRB 030115: IR observations with IRSF/SIRIUS
  82. GRB030115, afterglow candidate
  83. GRB 021211: R-band observations at late-time
  84. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  85. GRB 030115 : Possible IR counterpart
  86. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  87. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  88. GRB 030115: APO Optical Observations
  89. VLT spectroscopy of the probable host of GRB 021211
  90. GRB 021211: Probable Host and Underlying Supernova
  91. GRB 021112: Evidence for Another Dark Optical Afterglow
  92. GRB 021219: OSN optical observations
  93. GRB021219, optical observations
  94. GRB021219, optical observation by MASTER
  95. GRB021219: a long GRB localized by INTEGRAL
  96. GRB021211: APO optical observations
  97. XRF 020903 : HST observations
  98. GRB 021201: Optical Observations
  99. GRB 021211: CTIO observations
  100. GRB021211, BVRI field photometry

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