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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"

15722 results found.

  1. GRB 030913, optical candidate
  2. GRB030913: AAVSO optical observations
  3. GRB030913 (=H2849): Confirmation of the Flight Localization
  4. Magellan Observations of GRB030725 (=H2779)
  5. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  6. GRB 030913: Optical limit at RIKEN
  7. XRF030824: Optical observations
  8. IBAS detection of bursts from SGR 1806-20
  9. XRF030824: Second-epoch Palomar observations
  10. XRF030824: optical observations
  11. GRB030823: optical observations
  12. GRB030823: Palomar observations
  13. GRB030823: optical observation at Tokyo Tech
  14. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  15. IPN detection of continued activity from SGR1806-20
  16. GRB 030817 = H2808 TAROT optical observations
  17. SGR 1808-20 (=H2802): A Possible new SGR
  18. GRB 021206 Optical Observations
  19. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  20. XRF 030723: Detection of a rebrightening in the optical afterglow
  21. GRB030725: Optical observations
  22. XRF030723, BVRcIc field photometry update
  23. GRB021206 optical counterpart upper limit
  24. IPN triangulation of GRB030725 (=H2779; small error box)
  25. XRF030723 (=H2777): Second Epoch Magellan Observations
  26. GRB 030725: optical observations.
  27. GRB030725, optical transient observations
  28. XRF030723 Radio Observations
  29. XRF 030723: confirmation of fading optical counterpart
  30. XRF030723(=H2777): Chandra Observations
  31. Magellan Observations of XRF030723 (=H2777)
  32. GRB030723: Upper limits from historical observations
  33. GRB030725, possible optical transient
  34. XRF030723: Palomar observations and proposed counterpart
  35. GRB030725 (=H2779): A Bright GRB Localized by HETE
  36. XRF030723: optical observations
  37. XRF030723 (= H2777): Chandra Observations Scheduled
  38. XRF030723, BVRcIc field photometry
  39. XRF 030723, optical observations
  40. XRF030723, optical observations
  41. XRF 030723, optical observations
  42. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  43. GRB030723, optical observations
  44. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  45. GRB030329: Subaru Optical Spectroscopy
  46. GRB030329: RTT150 optical observations
  47. GRBlog: Compilation of all GCN Circ. data
  48. GRB030329, optical observation in May
  49. GRB030418: R optical observations
  50. HETE detection of burst from SGR1806-20
  51. GRB 021206, Radio afterglow candidate
  52. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  53. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  54. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  55. GRB 030528: Optical Observations
  56. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  57. GRB030329, SPM optical observations
  58. GRB 030519B: optical observations.
  59. MASTER: optical observation GRB030601
  60. GRB030528(=H2724): Revised SXC Localization
  61. GRB 030329: optical observations
  62. GRB 030329/SN 2003dh: Jitter Episode
  63. GRB 030528, Teramo optical observation
  64. GRB 030528 Bisei optical observation
  65. GRB030528 (H2724): A long GRB localized by HETE
  66. GRB 030329: Optical Observations
  67. GRB 030528: Optical observations at RIKEN
  68. GRB 030528 (=H2724) Kyoto optical observation
  69. GRB 030416: Optical Observations
  70. GRB 030329: optical photometry at various french observatories
  71. GRB 030329: optical photometry at Belesta observatory (France)
  72. GRB030329, Optical observations
  73. GRB 030329: HST ACS Observations of the Host
  74. GRB 030329 Optical Observations
  75. GRB030329: XMM-Newton observation
  76. GRB030324: Further Observations of the Candidate Optical Afterglow
  77. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  78. GRB 030418: Second Epoch Optical Observations with Magellan
  79. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  80. GRB 030329: Optical limit (contemporaneous imaging)
  81. GRB030329: RTT150 optical observations
  82. GRB030329, BVRI photometry
  83. GRB030429, refiend optical brightness
  84. GRB 030329: Optical limit (contemporaneous photography)
  85. GRB030418, BVRcIc field photometry
  86. GRB030429, BVRcIc field photometry
  87. GRB030429: RTT150 optical obs., correction to GCN 2208
  88. GRB 030329: High-Resolution Spectroscopy of the Host
  89. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  90. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  91. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  92. GRB030429: RTT150 optical observations, a possible host galaxy
  93. GRB030329: RTT150 optical observations and upper limit for a host
  94. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  95. GRB030501, optical observation
  96. GRB030501 observation report
  97. GRB030329: RTT150 optical observations and upper limit for a host
  98. GRB 030429: Radio Observations
  99. GRB 030429: redshift from VLT spectroscopy
  100. GRB 030329 Optical Observations

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