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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"

16174 results found.

  1. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  2. GRB 040323, a dark GRB ?
  3. GRB040223, improved XMM position
  4. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  5. MASTER: RXTE GRB040308 optical observation
  6. RXTE GRB040229 optical observation: no candidate
  7. GRB 040228 Optical observations
  8. GRB040228 : KISO optical follow-up observation
  9. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  10. GRB 040223 : Optical observation (non-detection)
  11. GRB031111, optical observations
  12. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  13. GRB040106: refined X-ray transient position
  14. SN 2003dh/GRB030329 late-time optical spectroscopy
  15. GRB040106, Radio Observations
  16. GRB040106, likely optical afterglow
  17. GRB040106: Second Epoch Optical Observations
  18. GRB 031220: Optical observations of Chandra X-ray sources
  19. GRB040106: optical observations with REM+ROSS
  20. GRB 040106: Optical observations
  21. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  22. GRB 031220 : Kyoto Optical Observation
  23. GRB 031220: Optical observation at Tokyo Tech
  24. GRB031220: ROTSE-IIIb Optical Limits
  25. GRB031220 : Optical Observation of Lulin Observatory
  26. GRB 031203 I-band monitoring
  27. GRB 031203: Discovery of a dust echo
  28. GRB 031203: SMARTS optical monitoring
  29. GRB 031203: Optical/IR Astrometry
  30. IPN/HETE localization of GRB031203B (=H2949; large error box)
  31. GRB031203 : Optical Observation of Lulin Observatory
  32. GRB031203: Optical Observations
  33. GRB 031203: Optical/IR SMARTS Observations
  34. GRB031111A, prompt optical observations
  35. GRB 031111B (= H2925) : Kyoto Optical Observation
  36. GRB 031111: Optical observations
  37. GRB 031111, optical observations
  38. SN 2003jd (SN/GRB?) -- X-ray Observations
  39. XRF031109 (=H2919): A very long XRF localized by HETE
  40. Lulin optical follow-up observations of GRB031026
  41. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  42. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  43. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  44. GRB031026 : KISO optical follow-up observation
  45. IPN detection of continued activity from SGR1806-20
  46. XRF 030723: Subaru Optical Observations
  47. XRF 030723: Detection of the likely host galaxy
  48. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  49. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  50. GRB030913: Subaru Optical Observations
  51. GRB 030913: ROTSE-3c Optical Observations
  52. GRB030913, candidate afterglow observations
  53. GRB 030913, optical candidate
  54. GRB030913: AAVSO optical observations
  55. GRB030913 (=H2849): Confirmation of the Flight Localization
  56. Magellan Observations of GRB030725 (=H2779)
  57. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  58. GRB 030913: Optical limit at RIKEN
  59. XRF030824: Optical observations
  60. IBAS detection of bursts from SGR 1806-20
  61. XRF030824: Second-epoch Palomar observations
  62. XRF030824: optical observations
  63. GRB030823: optical observations
  64. GRB030823: Palomar observations
  65. GRB030823: optical observation at Tokyo Tech
  66. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  67. IPN detection of continued activity from SGR1806-20
  68. GRB 030817 = H2808 TAROT optical observations
  69. SGR 1808-20 (=H2802): A Possible new SGR
  70. GRB 021206 Optical Observations
  71. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  72. XRF 030723: Detection of a rebrightening in the optical afterglow
  73. GRB030725: Optical observations
  74. XRF030723, BVRcIc field photometry update
  75. GRB021206 optical counterpart upper limit
  76. IPN triangulation of GRB030725 (=H2779; small error box)
  77. XRF030723 (=H2777): Second Epoch Magellan Observations
  78. GRB 030725: optical observations.
  79. GRB030725, optical transient observations
  80. XRF030723 Radio Observations
  81. XRF 030723: confirmation of fading optical counterpart
  82. XRF030723(=H2777): Chandra Observations
  83. Magellan Observations of XRF030723 (=H2777)
  84. GRB030723: Upper limits from historical observations
  85. GRB030725, possible optical transient
  86. XRF030723: Palomar observations and proposed counterpart
  87. GRB030725 (=H2779): A Bright GRB Localized by HETE
  88. XRF030723: optical observations
  89. XRF030723 (= H2777): Chandra Observations Scheduled
  90. XRF030723, BVRcIc field photometry
  91. XRF 030723, optical observations
  92. XRF030723, optical observations
  93. XRF 030723, optical observations
  94. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  95. GRB030723, optical observations
  96. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  97. GRB030329: Subaru Optical Spectroscopy
  98. GRB030329: RTT150 optical observations
  99. GRBlog: Compilation of all GCN Circ. data
  100. GRB030329, optical observation in May

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