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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

22062 results found.

  1. IPN triangulation of GRB031024 (annulus)
  2. GRB030329: radio observations at RT-22 (CrAO)
  3. XRF 030824: additional observations at CFHT
  4. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  5. XRF 030723: Subaru Optical Observations
  6. XRF 030824: observations at CFHT
  7. GRB030913: Subaru Optical Observations
  8. GRB 030913: ROTSE-3c Optical Observations
  9. GRB030913, candidate afterglow observations
  10. GRB 030913, optical candidate
  11. GRB030913: AAVSO optical observations
  12. GRB 030913, BOOTES observations
  13. GRB030913 (=H2849): Confirmation of the Flight Localization
  14. GRB030913 (=H2849): TAROT Observations
  15. Magellan Observations of GRB030725 (=H2779)
  16. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  17. XRF030824: Optical observations
  18. IBAS detection of bursts from SGR 1806-20
  19. Radio Observations of SGR1806-20
  20. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  21. XRF030824: Second-epoch Palomar observations
  22. XRF030824: optical observations
  23. GRB030823: optical observations
  24. GRB030823: Palomar observations
  25. XRF030824: Palomar observations
  26. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  27. RAPTOR observations of GRB030823
  28. Lulin follow-up observations of GRB030823
  29. Summary of recent IPN and HETE detections of SGR bursts
  30. GRB 030817 = H2808 TAROT optical observations
  31. SGR 1808-20 (=H2802): A Possible new SGR
  32. GRB 021206 Optical Observations
  33. XRF 030723: Detection of a rebrightening in the optical afterglow
  34. GRB030725: Optical observations
  35. GRB021206 optical counterpart upper limit
  36. XRF030723: Re-analysis of ROTSE-III early images
  37. XRF030723 (=H2777): Second Epoch Magellan Observations
  38. GRB 030725: optical observations.
  39. GRB030725, optical transient observations
  40. XRF030723 Radio Observations
  41. XRF 030723: confirmation of fading optical counterpart
  42. XRF030723(=H2777): Chandra Observations
  43. XRF 030723: VLT spectra
  44. Magellan Observations of XRF030723 (=H2777)
  45. GRB030723: Upper limits from historical observations
  46. GRB030725, possible optical transient
  47. XRF030723: Palomar observations and proposed counterpart
  48. XRF030723: optical observations
  49. XRF030723 (= H2777): Chandra Observations Scheduled
  50. XRF030723, ROTSE-III Early Observations
  51. XRF030723, BVRcIc field photometry
  52. XRF 030723, optical observations
  53. XRF030723, optical observations
  54. XRF 030723, optical observations
  55. GRB030723, optical observations
  56. Konus-Wind detection of the bursts from SGR1806-20 region
  57. SGR 1806-20, submm observations
  58. RXTE PCA Observations of SGR1806-20 Region
  59. GRB030329: RTT150 optical observations
  60. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  61. GRB030329, optical observation in May
  62. GRB030418: R optical observations
  63. GRB 021206, Radio afterglow candidate
  64. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  65. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  66. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  67. GRB 030528: Optical Observations
  68. GRB 030528: tentative NIR counterpart
  69. GRB 030528, radio observations
  70. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  71. GRB030329, further radio observations at GMRT
  72. GRB030329, SPM optical observations
  73. GRB030528: Chandra TOO Planned
  74. GRB 030519B: optical observations.
  75. MASTER: optical observation GRB030601
  76. GRB030528(=H2724): Revised SXC Localization
  77. GRB 030329: optical observations
  78. GRB 030329/SN 2003dh: Jitter Episode
  79. GRB 030329: Correction to GCN 2254
  80. GRB 030329: Optical Observations
  81. GRB 030528: Optical observations at RIKEN
  82. GRB 030416: Optical Observations
  83. GRB 030329: optical photometry at various french observatories
  84. GRB030329, Optical observations
  85. GRB 030329/SN 2003dh: Possible increase in brightness
  86. GRB 030329: HST ACS Observations of the Host
  87. GRB 030329 Optical Observations
  88. GRB030329: XMM-Newton observation
  89. GRB 021004: HST observations
  90. GRB030324: Further Observations of the Candidate Optical Afterglow
  91. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  92. GRB 030418: Second Epoch Optical Observations with Magellan
  93. HETE GRB030329, correction to Rc Observations in Loiano
  94. GRB 030329: Optical limit (contemporaneous imaging)
  95. GRB 030501: final TAROT limits
  96. GRB030329: RTT150 optical observations
  97. GRB030329, BVRI photometry
  98. GRB030429: RTT150 optical observations, a possible host galaxy
  99. GRB030329: RTT150 optical observations and upper limit for a host
  100. GRB030501, optical observation

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