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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28062 results found.

  1. GRB030227: Kiso optical observations
  2. GRB 030227: Kyoto optical observation
  3. GRB 030226, optical light curve
  4. GRB030227 localized by INTEGRAL
  5. GRB 030226 : Predicted light curve
  6. GRB030226: ESI spectroscopy
  7. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  8. GRB 030226 simultaneous optical observations
  9. GRB 030226, optical observations
  10. GRB030226: Optical decay index
  11. GRB 030226 Optical Spectra and R,I,z' Imaging
  12. GRB: Non-Referencing of GCN Circulars.
  13. IPN triangulation of GRB030217 (small error box)
  14. GRB 030131: marginal optical detection
  15. GRB 030204: Optical Observations
  16. GRB030204 field photometry
  17. GRB020819: Kiso R and I band observations
  18. GRB030131: Candidate Optical Afterglow
  19. IPN triangulation of GRB030204 (small error box)
  20. GRB 030131, optical observations
  21. GRB 030131: afterglow candidate
  22. GRB 030115, late-time optical observations
  23. GRB030131: corrected INTEGRAL position
  24. GRB 020819: Host galaxy at Radio Position
  25. IPN triangulation of GRB030131
  26. GRB 030131 optical observations
  27. GRB 030131 optical observations
  28. A long GRB detected by INTEGRAL
  29. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  30. GRB 030115, simultaneous observations by BOOTES-1
  31. GRB 030115: IR observations with IRSF/SIRIUS
  32. IPN triangulation of GRB030115C (large error box)
  33. GRB030115, afterglow candidate
  34. GRB 021211: R-band observations at late-time
  35. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  36. GRB 030115 : Possible IR counterpart
  37. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  38. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  39. GRB 030115: APO Optical Observations
  40. Information about where HETE will be pointing
  41. VLT spectroscopy of the probable host of GRB 021211
  42. IPN triangulation of GRB030101 (two large error boxes)
  43. GRB 021211: Probable Host and Underlying Supernova
  44. GRB 021112: Evidence for Another Dark Optical Afterglow
  45. GRB 021219: OSN optical observations
  46. GRB021219, optical observations
  47. GRB021219, optical observation by MASTER
  48. VLT spectra of GRB 021211 revisited
  49. GRB021219: a long GRB localized by INTEGRAL
  50. GRB021211: APO optical observations
  51. XRF 020903 : HST observations
  52. GRB 021201: Optical Observations
  53. GRB 021211: CTIO observations
  54. GRB021211, BVRI field photometry
  55. GRB021211: Optical observations in CrAO
  56. GRB 021211, optical observations
  57. GRB021211: Kiso Observations
  58. GRB 021201, optical observations
  59. GRB021211: Optical observations
  60. GRB 021201 (short/hard), NOT observations
  61. SUB-MM SEARCH FOR GRB 021211
  62. Chandra observation of the IPN error box of GRB021201 (short/hard)
  63. GRB 021211, R- and I-band observations
  64. GRB021211 - Upper limits from recent and historical observations
  65. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  66. IPN triangulation of GRB021206 (small error box)
  67. IPN triangulation of GRB021205 (large error box)
  68. GRB021201, BVRcIc field photometry
  69. GRB 021201: BOOTES simultaneous optical observations
  70. IPN triangulation of GRB021201 (short/hard burst, small error box)
  71. GRB021004, late time optical observations
  72. GRB021004 Chandra Observation
  73. IPN detection of continued SGR1900+14 activity
  74. Improved IPN error box for GRB021125
  75. IPN BURST POSITION
  76. IPN triangulation of GRB021125 (INTEGRAL BURST)
  77. GRB021125 : A long GRB localized by INTEGRAL
  78. IPN confirmation of the reactivation of SGR1900+14
  79. GRB021113, SPI ACS observation
  80. GRB 021112: Afterglow or Variable Star?
  81. GRB021113: optical observations at Bisei
  82. GRB 021113: Evidence for a Dark Optical Afterglow
  83. GRB021112, BVRI field photometry
  84. GRB 021112: Variable Source in R-band search
  85. GRB021112: Optical Observations
  86. IPN triangulation of GRB021113 (=H2449; annulus)
  87. GRB 021113: Optical observations
  88. GRB 021112: RAPTOR Observations
  89. GRB021113 (=H2449): A Long GRB Localized by HETE
  90. GRB021112 (=H2448): A Long GRB Localized by HETE
  91. GRB 021016: Optical Observations
  92. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  93. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  94. SGR1900+14 activity, November 2-4, 2002
  95. GRB021104: optical observations
  96. Detection of activity from SGR 1900+14 with the RXTE/PCA
  97. IPN triangulation of GRB021027 (single large error box)
  98. IPN triangulation of GRB021027 (two large error boxes)
  99. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  100. GRB 021004: optical observations

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