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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"

11755 results found.

  1. AAVSO V & R observations of GRB030329
  2. GRB 030329: optical observations
  3. GRB030329 - Light curve flattening
  4. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  5. GRB 030329: visual observations
  6. GRB030328: X-ray Afterglow Observed with Chandra
  7. GRB 030329, R-band observations, supplement
  8. GRB030329:optical observations by MASTER
  9. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  10. RXTE detection of GRB 030329 afterglow
  11. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  12. GRB 030328: Finding chart
  13. GRB 030328: Optical afterglow candidate
  14. GRB030324, optical observations
  15. GRB030324, Optical Observations
  16. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  17. GRB 030324, optical observations
  18. IPN triangulation of GRB030317 (annulus)
  19. GRB 030227: Optical limit at RIKEN
  20. IPN triangulation of GRB030306 (single small error box)
  21. IPN triangulation of GRB030306 (two small error boxes)
  22. IPN triangulation of GRB030306 (intense; annulus only so far)
  23. GRB030226: Analysis of Chandra data
  24. GRB 030227: fading of candidate optical afterglow 'S1-A'
  25. GRB 030227, possible optical counterpart of XMM-Newton source
  26. GRB030227 - faint tentative OT candidate
  27. GRB 030227: Kyoto optical observation
  28. GRB030227 localized by INTEGRAL
  29. GRB 030226, optical observations
  30. GRB 030226 Optical Spectra and R,I,z' Imaging
  31. GRB030226: Candidate optical afterglow
  32. GRB 030217: Optical Observations at 4, 5, and 6 Days
  33. GRB030217: optical observations
  34. GRB030131: Kiso optical limit for corrected position
  35. GRB030131: Optical limits for corrected position
  36. GRB 030131: afterglow candidate
  37. GRB030131: Optical limit
  38. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  39. GRB 030115, simultaneous observations by BOOTES-1
  40. GRB030115: R-band counterpart of IR candidate
  41. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  42. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  43. GRB 030115, no optical candidate
  44. IPN triangulation of GRB030102B (portion of annulus)
  45. GRB on 20030101 seen by SPI-ACS
  46. GRB021219: a long GRB localized by INTEGRAL
  47. IPN detection of continued activity from SGR1806-20
  48. GRB 021201: Optical Observations
  49. GRB 021211: early break in light curve
  50. GRB021211: Optical observations in CrAO
  51. Chandra observation of the IPN error box of GRB021201 (short/hard)
  52. GRB 021211 Milagro GeV/TeV Observations
  53. GRB021211, OT at 108 s
  54. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  55. HETE 2493: Optical observations
  56. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  57. IPN detection of renewed activity from SGR1806-20
  58. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  59. Improved IPN error box for GRB021125
  60. GRB021125 : A long GRB localized by INTEGRAL
  61. IPN confirmation of the reactivation of SGR1900+14
  62. IPN triangulation of GRB021119 (annulus)
  63. GRB021112: Optical Observations
  64. GRB021113 (=H2449): A Long GRB Localized by HETE
  65. GRB021112 (=H2448): A Long GRB Localized by HETE
  66. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  67. GRB 021004: optical observations
  68. IPN triangulation of GRB021020 (smaller error box)
  69. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  70. IPN triangulation of GRB021020
  71. GRB 021016, optical observations
  72. GRB 021004: VRI observations at TNG: possible break
  73. GRB 021008, optical observations
  74. GRB021016(=H2397): A Long GRB Localized by HETE
  75. GRB021004: NIR and Optical observations
  76. GRB 021004: Optical measurement at OHP
  77. GRB 021004: optical spectroscopy
  78. GRB021004: BVRc photometry
  79. GRB 021004: Optical Photometry at 2.5 Days
  80. GRB 021004 radio observation
  81. GRB 021004: Optical Observations
  82. GRB 021004: Optical Photometry at 1.5 Days
  83. GRB021004, Optical Observations
  84. GRB 021004, optical observations
  85. GRB 021004, SPM optical observations
  86. GRB 021004: steepening of the optical decay slope
  87. XRF020903, BVRI field photometry
  88. GRB 020903: Optical observations at RIKEN
  89. XRF 020903: Supernova
  90. IPN triangulation of GRB020926 (two large error boxes)
  91. GRB020924 (ecliptic latitude-only localization)
  92. IPN triangulation of GRB020923 (two error boxes)
  93. Improved IPN position for GRB020918 (two large error boxes)
  94. IPN triangulation of GRB020911 (2 large error boxes)
  95. INTEGRAL GRBs added to GCN
  96. GRB020812: optical observation
  97. Second epoch K band imaging of GRB 020819
  98. GRB 020812: early time optical observation at Ouda Station
  99. GRB020813: Magellan BVRI Photometry
  100. GRB 020819 : OT candidate - confirmation of non variability

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