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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').
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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"

12090 results found.

  1. GRB 030329: optical observations
  2. GRB030329 - Light curve flattening
  3. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  4. GRB 030329: visual observations
  5. GRB030328: X-ray Afterglow Observed with Chandra
  6. GRB 030329, R-band observations, supplement
  7. GRB030329:optical observations by MASTER
  8. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  9. RXTE detection of GRB 030329 afterglow
  10. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  11. GRB 030328: Finding chart
  12. GRB 030328: Optical afterglow candidate
  13. GRB030324, optical observations
  14. GRB030324, Optical Observations
  15. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  16. GRB 030324, optical observations
  17. IPN triangulation of GRB030317 (annulus)
  18. GRB 030227: Optical limit at RIKEN
  19. IPN triangulation of GRB030306 (single small error box)
  20. IPN triangulation of GRB030306 (two small error boxes)
  21. IPN triangulation of GRB030306 (intense; annulus only so far)
  22. GRB030226: Analysis of Chandra data
  23. GRB 030227: fading of candidate optical afterglow 'S1-A'
  24. GRB 030227, possible optical counterpart of XMM-Newton source
  25. GRB030227 - faint tentative OT candidate
  26. GRB 030227: Kyoto optical observation
  27. GRB030227 localized by INTEGRAL
  28. GRB 030226, optical observations
  29. GRB 030226 Optical Spectra and R,I,z' Imaging
  30. GRB030226: Candidate optical afterglow
  31. GRB 030217: Optical Observations at 4, 5, and 6 Days
  32. GRB030217: optical observations
  33. GRB030131: Kiso optical limit for corrected position
  34. GRB030131: Optical limits for corrected position
  35. GRB 030131: afterglow candidate
  36. GRB030131: Optical limit
  37. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  38. GRB 030115, simultaneous observations by BOOTES-1
  39. GRB030115: R-band counterpart of IR candidate
  40. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  41. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  42. GRB030115: R-band observations at Asiago
  43. GRB 030115: APO Optical Observations
  44. GRB 030115, no optical candidate
  45. IPN triangulation of GRB030102B (portion of annulus)
  46. GRB on 20030101 seen by SPI-ACS
  47. IPN triangulation of GRB021219
  48. GRB021219: a long GRB localized by INTEGRAL
  49. IPN detection of continued activity from SGR1806-20
  50. GRB 021201: Optical Observations
  51. GRB 021211: early break in light curve
  52. GRB021211: Optical observations in CrAO
  53. Chandra observation of the IPN error box of GRB021201 (short/hard)
  54. GRB 021211 Milagro GeV/TeV Observations
  55. GRB021211, OT at 108 s
  56. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  57. HETE 2493: Optical observations
  58. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  59. IPN detection of renewed activity from SGR1806-20
  60. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  61. IPN detection of continued SGR1900+14 activity
  62. Improved IPN error box for GRB021125
  63. GRB021125 : A long GRB localized by INTEGRAL
  64. IPN confirmation of the reactivation of SGR1900+14
  65. IPN detection of possible reactivation of SGR1900+14
  66. IPN triangulation of GRB021119 (annulus)
  67. GRB021112: Optical Observations
  68. GRB021113 (=H2449): A Long GRB Localized by HETE
  69. GRB021112 (=H2448): A Long GRB Localized by HETE
  70. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  71. SGR1900+14 activity, November 2-4, 2002
  72. Detection of activity from SGR 1900+14 with the RXTE/PCA
  73. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  74. GRB 021004: optical observations
  75. IPN triangulation of GRB021020 (smaller error box)
  76. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  77. IPN triangulation of GRB021020
  78. GRB 021016, optical observations
  79. GRB 021004: VRI observations at TNG: possible break
  80. GRB 021008, optical observations
  81. GRB021016(=H2397): A Long GRB Localized by HETE
  82. GRB021004: NIR and Optical observations
  83. GRB 021004: Optical measurement at OHP
  84. GRB 021004: optical spectroscopy
  85. GRB021004: BVRc photometry
  86. GRB 021004: Optical Photometry at 2.5 Days
  87. GRB 021004 radio observation
  88. GRB 021004: Optical Observations
  89. GRB 021004: Optical Photometry at 1.5 Days
  90. GRB021004, Optical Observations
  91. GRB 021004, optical observations
  92. GRB 021004, SPM optical observations
  93. GRB 021004: steepening of the optical decay slope
  94. XRF020903, BVRI field photometry
  95. GRB 020903: Optical observations at RIKEN
  96. XRF 020903: Supernova
  97. IPN triangulation of GRB020926 (two large error boxes)
  98. GRB020924 (ecliptic latitude-only localization)
  99. IPN triangulation of GRB020923 (two error boxes)
  100. Improved IPN position for GRB020918 (two large error boxes)

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