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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"

16162 results found.

  1. GRB040106: refined X-ray transient position
  2. SN 2003dh/GRB030329 late-time optical spectroscopy
  3. GRB040106, Radio Observations
  4. GRB040106, likely optical afterglow
  5. GRB040106: Second Epoch Optical Observations
  6. GRB 031220: Optical observations of Chandra X-ray sources
  7. GRB040106: optical observations with REM+ROSS
  8. GRB 040106: Optical observations
  9. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  10. GRB 031220 : Kyoto Optical Observation
  11. GRB 031220: Optical observation at Tokyo Tech
  12. GRB031220: ROTSE-IIIb Optical Limits
  13. GRB031220 : Optical Observation of Lulin Observatory
  14. GRB 031203 I-band monitoring
  15. GRB 031203: Discovery of a dust echo
  16. GRB 031203: SMARTS optical monitoring
  17. GRB 031203: Optical/IR Astrometry
  18. IPN/HETE localization of GRB031203B (=H2949; large error box)
  19. GRB031203 : Optical Observation of Lulin Observatory
  20. GRB031203: Optical Observations
  21. GRB 031203: Optical/IR SMARTS Observations
  22. GRB031111A, prompt optical observations
  23. GRB 031111B (= H2925) : Kyoto Optical Observation
  24. GRB 031111: Optical observations
  25. GRB 031111, optical observations
  26. SN 2003jd (SN/GRB?) -- X-ray Observations
  27. XRF031109 (=H2919): A very long XRF localized by HETE
  28. Lulin optical follow-up observations of GRB031026
  29. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  30. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  31. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  32. GRB031026 : KISO optical follow-up observation
  33. IPN detection of continued activity from SGR1806-20
  34. XRF 030723: Subaru Optical Observations
  35. XRF 030723: Detection of the likely host galaxy
  36. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  37. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  38. GRB030913: Subaru Optical Observations
  39. GRB 030913: ROTSE-3c Optical Observations
  40. GRB030913, candidate afterglow observations
  41. GRB 030913, optical candidate
  42. GRB030913: AAVSO optical observations
  43. GRB030913 (=H2849): Confirmation of the Flight Localization
  44. Magellan Observations of GRB030725 (=H2779)
  45. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  46. GRB 030913: Optical limit at RIKEN
  47. XRF030824: Optical observations
  48. IBAS detection of bursts from SGR 1806-20
  49. XRF030824: Second-epoch Palomar observations
  50. XRF030824: optical observations
  51. GRB030823: optical observations
  52. GRB030823: Palomar observations
  53. GRB030823: optical observation at Tokyo Tech
  54. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  55. IPN detection of continued activity from SGR1806-20
  56. GRB 030817 = H2808 TAROT optical observations
  57. SGR 1808-20 (=H2802): A Possible new SGR
  58. GRB 021206 Optical Observations
  59. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  60. XRF 030723: Detection of a rebrightening in the optical afterglow
  61. GRB030725: Optical observations
  62. XRF030723, BVRcIc field photometry update
  63. GRB021206 optical counterpart upper limit
  64. IPN triangulation of GRB030725 (=H2779; small error box)
  65. XRF030723 (=H2777): Second Epoch Magellan Observations
  66. GRB 030725: optical observations.
  67. GRB030725, optical transient observations
  68. XRF030723 Radio Observations
  69. XRF 030723: confirmation of fading optical counterpart
  70. XRF030723(=H2777): Chandra Observations
  71. Magellan Observations of XRF030723 (=H2777)
  72. GRB030723: Upper limits from historical observations
  73. GRB030725, possible optical transient
  74. XRF030723: Palomar observations and proposed counterpart
  75. GRB030725 (=H2779): A Bright GRB Localized by HETE
  76. XRF030723: optical observations
  77. XRF030723 (= H2777): Chandra Observations Scheduled
  78. XRF030723, BVRcIc field photometry
  79. XRF 030723, optical observations
  80. XRF030723, optical observations
  81. XRF 030723, optical observations
  82. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  83. GRB030723, optical observations
  84. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  85. GRB030329: Subaru Optical Spectroscopy
  86. GRB030329: RTT150 optical observations
  87. GRBlog: Compilation of all GCN Circ. data
  88. GRB030329, optical observation in May
  89. GRB030418: R optical observations
  90. HETE detection of burst from SGR1806-20
  91. GRB 021206, Radio afterglow candidate
  92. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  93. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  94. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  95. GRB 030528: Optical Observations
  96. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  97. GRB030329, SPM optical observations
  98. GRB 030519B: optical observations.
  99. MASTER: optical observation GRB030601
  100. GRB030528(=H2724): Revised SXC Localization

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