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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"

6667 results found.

  1. GRB 031203: IR REM Observations
  2. GRB 031203 XMM-Newton observation
  3. IPN/HETE localization of GRB031109 (=H2917; large error box)
  4. GRB 031111: Optical observations
  5. Lulin optical follow-up observations of GRB031026
  6. GRB031026 : KISO optical follow-up observation
  7. XRF 030824: additional observations at CFHT
  8. XRF 030824: observations at CFHT
  9. Magellan Observations of GRB030725 (=H2779)
  10. XRF030723: Palomar observations and proposed counterpart
  11. XRF 030723, optical observations
  12. Konus-Wind detection of the bursts from SGR1806-20 region
  13. GRB030329: second XMM-Newton observation
  14. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  15. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  16. GRB 030528: tentative NIR counterpart
  17. GRB 030416: Optical Observations
  18. GRB 030329: Optical limit (contemporaneous photography)
  19. GRB 030429: IR photometry with IRSF/SIRIUS
  20. GRB030501: TAROT candidate afterglow present in archival images
  21. GRB 030429: confirmation of afterglow candidate
  22. GRB 030329 Oprical observations in Rozhen observatory
  23. GRB030418: Kiso near infrared observations
  24. IPN triangulation of GRB030410 (annulus)
  25. GRB030329: Near Infrared Observations at Gunma
  26. GRB 030329 Optical observations
  27. GRB 030329, BVRI photometry
  28. GRB030329: Optical observations
  29. GRB030329, optical observation
  30. GRB030329, optical observation
  31. GRB 030329, BRI photometry
  32. GRB 030329: fading X-ray afterglow with RXTE
  33. GRB 030324: Optical and NIR Observations
  34. GRB030329: R and B observations
  35. GRB 030329: OT B and R photometry, decline rate
  36. GRB030329: Upper limits from recent and historical observations.
  37. GRB 030328: optical observations
  38. GRB 030328: OT photometry
  39. GRB030323: Detection on 2003/03/24
  40. GRB 030320: Optical Observations
  41. GRB 030324, optical observations
  42. GRB030226, addendum to GCN 1892
  43. GRB 030226 Optical observations
  44. GRB 030226: Ic Observations
  45. XMM-Newton observation of GRB030227
  46. GRB 030226: Confirmed decay index
  47. GRB030217: optical observations
  48. GRB 030204: Optical Observations
  49. GRB020819: Kiso R and I band observations
  50. GRB 030204, optical observations
  51. GRB030131: Kiso optical limit for corrected position
  52. GRB030131: Kiso Observations
  53. GRB 030115: Further IR observations with IRSF/SIRIUS
  54. GRB 030115: IR observations with IRSF/SIRIUS
  55. GRB 021219: OSN optical observations
  56. GRB021211: Kiso Observations
  57. GRB021204: Kiso Observations
  58. Chandra observation of the IPN error box of GRB021201 (short/hard)
  59. GRB021113: Kiso Observations
  60. Detection of activity from SGR 1900+14 with the RXTE/PCA
  61. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  62. GRB021004: High-resolution optical spectroscopy
  63. XRF 020903 spectrum
  64. GRB 021004 redshift
  65. HETE fluences for GRB021004
  66. GRB 021004: Optical Observations
  67. GRB021004: Optical Spectroscopy
  68. XRF 020903: Correction to GCN 1560
  69. XRF 020903: VRI observations
  70. GRB020812: optical observations
  71. GRB 020813 multiband optical observations
  72. GRB/XRF 020427, detection of an underlying system with the VLT
  73. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  74. SGR-like Bursts from the AXP 1E 2259+586
  75. GRB 020531/Candidate Redshift
  76. GRB 020418, optical/near-IR observations
  77. GRB 020603, R-band observation
  78. GRB020531, optical observations
  79. HST detection of the likely host galaxy of GRB 020124
  80. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  81. GRB 020418: Optical observations
  82. GRB 020321: Candidate X-ray Counterparts
  83. GRB 020331: Candidate Optical Afterglow
  84. GRB 020331: NIR Observations
  85. GRB 020322: Optical Sources and Improved Astrometry
  86. GRB 020317: Optical observations
  87. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  88. GRB 020127, I-band observations starting 3.14-hr after the event
  89. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  90. GRB optical counterpart candidate in GCN 1217 is M dwarf
  91. GRB 011121: NIR observations, host galaxy?
  92. GRB 011121: Detection of Bright IR Counterpart
  93. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  94. GRB001109, Host Galaxy Spectroscopic Observations
  95. SGR1806-20: Localization by HETE
  96. SGR 1900+14 : RXTE observations
  97. GRB 010222: Keck Spectroscopy
  98. GRB 010222, Decay Slope Confirmed
  99. Redshift of the Optical Transient of GRB010222
  100. GRB010220, Radio and Optical Observations

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