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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"

20522 results found.

  1. IPN detection of continued activity from SGR1806-20
  2. GRB 030817 = H2808 TAROT optical observations
  3. SGR 1808-20 (=H2802): A Possible new SGR
  4. GRB 021206 Optical Observations
  5. XRF 030723: Detection of a rebrightening in the optical afterglow
  6. GRB030725: Optical observations
  7. GRB021206 optical counterpart upper limit
  8. XRF030723: Re-analysis of ROTSE-III early images
  9. XRF030723 (=H2777): Second Epoch Magellan Observations
  10. GRB 030725: optical observations.
  11. GRB030725, optical transient observations
  12. XRF030723 Radio Observations
  13. XRF 030723: confirmation of fading optical counterpart
  14. XRF030723(=H2777): Chandra Observations
  15. XRF 030723: VLT spectra
  16. Magellan Observations of XRF030723 (=H2777)
  17. GRB030723: Upper limits from historical observations
  18. GRB030725, possible optical transient
  19. XRF030723: Palomar observations and proposed counterpart
  20. XRF030723: optical observations
  21. XRF030723 (= H2777): Chandra Observations Scheduled
  22. XRF030723, ROTSE-III Early Observations
  23. XRF030723, BVRcIc field photometry
  24. XRF 030723, optical observations
  25. XRF030723, optical observations
  26. XRF 030723, optical observations
  27. GRB030723, optical observations
  28. Konus-Wind detection of the bursts from SGR1806-20 region
  29. SGR 1806-20, submm observations
  30. RXTE PCA Observations of SGR1806-20 Region
  31. GRB030329: RTT150 optical observations
  32. GRB030329, optical observation in May
  33. GRB030418: R optical observations
  34. GRB 021206, Radio afterglow candidate
  35. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  36. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  37. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  38. GRB 030528: Optical Observations
  39. GRB 030528, radio observations
  40. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  41. GRB030329, further radio observations at GMRT
  42. GRB030329, SPM optical observations
  43. GRB030528: Chandra TOO Planned
  44. GRB 030519B: optical observations.
  45. MASTER: optical observation GRB030601
  46. GRB 030329: optical observations
  47. GRB 030329/SN 2003dh: Jitter Episode
  48. GRB 030329: Optical Observations
  49. GRB 030528: Optical observations at RIKEN
  50. GRB 030416: Optical Observations
  51. GRB030329, Optical observations
  52. GRB 030329/SN 2003dh: Possible increase in brightness
  53. GRB 030329: HST ACS Observations of the Host
  54. GRB 030329 Optical Observations
  55. GRB030329: XMM-Newton observation
  56. GRB 021004: HST observations
  57. GRB030324: Further Observations of the Candidate Optical Afterglow
  58. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  59. GRB 030418: Second Epoch Optical Observations with Magellan
  60. HETE GRB030329, correction to Rc Observations in Loiano
  61. GRB030329: RTT150 optical observations
  62. GRB030329, BVRI photometry
  63. GRB 030329: High-Resolution Spectroscopy of the Host
  64. GRB030429: RTT150 optical observations, a possible host galaxy
  65. GRB030329: RTT150 optical observations and upper limit for a host
  66. GRB030501, optical observation
  67. GRB030329: RTT150 optical observations and upper limit for a host
  68. GRB 030429: Radio Observations
  69. GRB 030429: IR photometry with IRSF/SIRIUS
  70. GRB 030329 Optical Observations
  71. GRB030429: Optical Observations
  72. GRB 030501: TAROT possible candidate counterpart
  73. GRB 030429: confirmation of afterglow candidate
  74. GRB030429, possible optical counterpart
  75. GRB 030329 Oprical observations in Rozhen observatory
  76. GRB 030429: ROTSE-III observations
  77. GRB 030324: Radio Observations
  78. GRB030329 observed as a sudden ionospheric disturbance (SID)
  79. GRB030329, SPM optical observations (Correction)
  80. GRB030329, SPM optical observations
  81. GRB 030329, the review of the sky area in plate archive (1950-1998)
  82. Optical Observations of GRB 030418 with Magellan
  83. GRB 030329: optical spectropolarimetry at VLT
  84. GRB030329: optical polarization
  85. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  86. MASTER:optical observations GRB030418
  87. MASTER:optical observations probable GRB030414
  88. GRB030329: 444 AAVSO Measurements
  89. MASTER:optical observations GRB030416
  90. ROTSE-III prompt optical detections of GRB 030418
  91. GRB030418: Upper limits from recent and historical observations.
  92. GRB030418: Kiso near infrared observations
  93. GRB 030418: Optical afterglow
  94. GRB 030418: Optical afterglow candidate
  95. GRB030329: Optical Observations
  96. OT GRB 030329: early UBVRcIc spectral evolution
  97. GRB030329, UBVRI polarimetry, R-polarization
  98. GRB 030329: SARA Optical Observations
  99. OT GRB 030329: early spectrum
  100. GRB030329: VR Photometry at TNG

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