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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"

15981 results found.

  1. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  2. On Line Availability of Archival HETE Fregate Data and Lightcurves
  3. GRB040422: optical observations at Xinglong Observatory
  4. GRB040422: optical observations at CrAO
  5. GRB 040423 (=H3175): A Long GRB Localized by HETE
  6. GRB040422, optical observations at Loiano
  7. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  8. GRB 040422,optical observation
  9. GRB040422: optical and NIR observations at the VLT
  10. GRB 040403, deep optical observations
  11. MASTER: HETE Alert 3163, 3167 technical optical observation
  12. GRB 040403: Optical Observations
  13. GRB 040403 Optical Observations
  14. GRB 040403: Optical observations
  15. GRB 040403: optical observations
  16. GRB 040403: Optical Observations
  17. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  18. GRB 040323, a dark GRB ?
  19. GRB040223, improved XMM position
  20. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  21. MASTER: RXTE GRB040308 optical observation
  22. RXTE GRB040229 optical observation: no candidate
  23. GRB 040228 Optical observations
  24. GRB040228 : KISO optical follow-up observation
  25. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  26. GRB 040223 : Optical observation (non-detection)
  27. GRB031111, optical observations
  28. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  29. GRB040106: refined X-ray transient position
  30. SN 2003dh/GRB030329 late-time optical spectroscopy
  31. GRB040106, Radio Observations
  32. GRB040106, likely optical afterglow
  33. GRB040106: Second Epoch Optical Observations
  34. GRB 031220: Optical observations of Chandra X-ray sources
  35. GRB040106: optical observations with REM+ROSS
  36. GRB 040106: Optical observations
  37. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  38. GRB 031220 : Kyoto Optical Observation
  39. GRB 031220: Optical observation at Tokyo Tech
  40. GRB031220: ROTSE-IIIb Optical Limits
  41. GRB031220 : Optical Observation of Lulin Observatory
  42. GRB 031203: Discovery of a dust echo
  43. GRB 031203: SMARTS optical monitoring
  44. GRB 031203: Optical/IR Astrometry
  45. IPN/HETE localization of GRB031203B (=H2949; large error box)
  46. GRB031203 : Optical Observation of Lulin Observatory
  47. GRB031203: Optical Observations
  48. GRB 031203: Optical/IR SMARTS Observations
  49. GRB031111A, prompt optical observations
  50. GRB 031111B (= H2925) : Kyoto Optical Observation
  51. GRB 031111: Optical observations
  52. GRB 031111, optical observations
  53. SN 2003jd (SN/GRB?) -- X-ray Observations
  54. XRF031109 (=H2919): A very long XRF localized by HETE
  55. Lulin optical follow-up observations of GRB031026
  56. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  57. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  58. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  59. GRB031026 : KISO optical follow-up observation
  60. GRB030329: radio observations at RT-22 (CrAO)
  61. XRF 030723: Subaru Optical Observations
  62. XRF 030723: Detection of the likely host galaxy
  63. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  64. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  65. GRB030913: Subaru Optical Observations
  66. GRB 030913: ROTSE-3c Optical Observations
  67. GRB030913, candidate afterglow observations
  68. GRB 030913, optical candidate
  69. GRB030913: AAVSO optical observations
  70. GRB030913 (=H2849): Confirmation of the Flight Localization
  71. Magellan Observations of GRB030725 (=H2779)
  72. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  73. GRB 030913: Optical limit at RIKEN
  74. XRF030824: Optical observations
  75. XRF030824: Second-epoch Palomar observations
  76. XRF030824: optical observations
  77. GRB030823: optical observations
  78. GRB030823: Palomar observations
  79. GRB030823: optical observation at Tokyo Tech
  80. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  81. GRB 030817 = H2808 TAROT optical observations
  82. SGR 1808-20 (=H2802): A Possible new SGR
  83. GRB 021206 Optical Observations
  84. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  85. XRF 030723: Detection of a rebrightening in the optical afterglow
  86. GRB030725: Optical observations
  87. XRF030723, BVRcIc field photometry update
  88. GRB021206 optical counterpart upper limit
  89. IPN triangulation of GRB030725 (=H2779; small error box)
  90. XRF030723 (=H2777): Second Epoch Magellan Observations
  91. GRB 030725: optical observations.
  92. GRB030725, optical transient observations
  93. XRF030723 Radio Observations
  94. XRF 030723: confirmation of fading optical counterpart
  95. XRF030723(=H2777): Chandra Observations
  96. Magellan Observations of XRF030723 (=H2777)
  97. GRB030723: Upper limits from historical observations
  98. GRB030725, possible optical transient
  99. XRF030723: Palomar observations and proposed counterpart
  100. GRB030725 (=H2779): A Bright GRB Localized by HETE

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