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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"

3759 results found.

  1. LIGO/Virgo S190425z: COATLI Observations of Galaxies
  2. LIGO/Virgo S190426c: HAWC follow-up
  3. LIGO/Virgo S190425z: YAHPT Optical Observation
  4. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  5. LIGO/Virgo S190425z: KMTNet Observation
  6. LIGO/Virgo S190425z: Swope follow-up observations
  7. LIGO/Virgo S190425z: KPED Follow-Up Observations
  8. LIGO/Virgo S190425z: OVRO-LWA simultaneous low frequency radio observations of localization region
  9. LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
  10. LIGO/Virgo S190425z: Xinglong/Schmidt follow-up observations
  11. LIGO/Virgo S190408an: Gaia Photometric Alerts transient candidates
  12. LIGO/Virgo S190425z: Fermi GBM Observations
  13. LIGO/Virgo S190425z: Lick/KAIT Follow-Up Observations
  14. Fermi GRB190425.09 Global MASTER-Net observations report
  15. LIGO/Virgo S190421ar: TAROT-GRANDMA observation report.
  16. LIGO/Virgo S190421ar: Lick/KAIT Follow-Up Observations
  17. Fermi GRB190420.98 Global MASTER-Net observations report
  18. Fermi GRB190419.41 Global MASTER-Net observations report
  19. LIGO/Virgo S190412m: GOTO optical coverage - no notable counterparts
  20. LIGO/Virgo S190408an: MAXI/GSC Observations
  21. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  22. LIGO/Virgo S190408an: CALET Observations
  23. CORRECTED TARGET NAME: GRB 190408A: MAXI/GSC detection
  24. GRB 140408A: MAXI/GSC detection
  25. GRB 140404B: MAXI/GSC detection
  26. GRB 190331B: Swift observations of a ground-detected burst
  27. GRB 190326A: 2.2m CAHA telescope optical limit
  28. Swift Trigger 895479: Detection of GRO J2058+42
  29. Swift Trigger 895257: Detection of GRO J2058+42 in outburst
  30. GRB 190326A: Swift detection of a short burst
  31. SWIFT GRB190323.85 Global MASTER-Net observations report
  32. Swift Trigger 894268: Detection of GRO J2058+42 in outburst
  33. Fermi Trigger 574676902 / GRB 190319353: BALROG localization
  34. GRB190219A: MASTER Global Robotic Net optical observation
  35. GRB190211A: GROWTH-India detection of optical afterglow
  36. GRB 190211A: DOAO optical observation
  37. Trigger 888312: Swift detection of 4U 1901+03
  38. GRB 190204A: MAXI/GSC detection
  39. Swift Trigger 887541: Swift detection of Swift J1728.9-3613
  40. IPN Triangulation of GRB 190129B (long/extremely bright)
  41. Swift Trigger 886157: MASTER optical observation
  42. Trigger 885456: Swift detection of MAXI J1631-479
  43. GRB 190114C: RTT150 optical observations
  44. GRB 190114B: optical afterglow observations in Mondy and Abastumani observatories
  45. GRB 190114B: Mondy optical afterglow detection
  46. GRB 190114C: NOT optical counterpart and redshift
  47. Konus-Wind observation of GRB 190103A
  48. GRB 190109A: Swift-BAT refined analysis
  49. Trigger 882561: Swift detection of MAXI J1631-479
  50. GRB 181228A: Mondy and AbAO optical upper limits
  51. GRB 181228A: possible NOT optical detection
  52. GRB 181228A: Xinglong-2.16m optical upper limit
  53. FRB 181228: Global MASTER Net optical inspection
  54. GRB 181227A: Global MASTER Net oprtical inspection
  55. Swift Trigger 880127 is not a GRB
  56. GRB 181228A: TSHAO optical upper limit
  57. GRB 181228A: Fermi GBM observation
  58. GRB 181228A: Global MASTER Net OT detection
  59. GRB 181228A: REM NIR detection
  60. GRB 181126A: MeerKAT radio observation
  61. GRB 181126B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 564897175)
  62. Swift Trigger 874754 is likely not an astrophysical event
  63. GRB 181201A: Zeiss-1000/CrAO optical observations
  64. GRB 181201A: Swift-XRT afterglow detection
  65. Short-duration GRB 181121.4: MASTER-Tavrida possible OT detection near the PGC galaxy during large Fermi error box inspection
  66. GRB 181028A: CALET Gamma-Ray Burst Monitor detection
  67. GRB 181030A: Swift detection of a burst with a possible optical counterpart
  68. GRB 181028A: Fermi GBM observation
  69. GRB 181028A: Fermi-LAT detection
  70. GRB 181027A: Swift detection of a burst
  71. Swift Trigger 866757: is probably not a GRB
  72. GRB 181011A: MAXI/GSC detection
  73. GRB 181008A: Insight-HXMT/HE detection
  74. GRB 181002A: Swift detection of a burst
  75. GRB 180923A: MAXI/GSC detection
  76. GRB 180914B : continued TSHAO optical observations
  77. GRB 180914B: MASTER OT automatic dtection
  78. IceCube-180908A: CALET Gamma-Ray Burst Monitor upper limits
  79. GRB 180904A: BOOTES-2/TELMA early observations
  80. GRB 180904A: Swift detection of a burst
  81. GRB 180829A/MAXI J0406-019: MAXI/GSC detection
  82. GRB 180828A: Fermi GBM observation
  83. GRB 180818B: Fermi GBM observations
  84. Konus-Wind observation of GRB 180809B
  85. GRB 180809B: CALET Gamma-Ray Burst Monitor detection
  86. GRB 180809B: Swift detection of a burst with an optical afterglow
  87. GRB 180806.94: MASTER possible OT detection in Fermi GMB trigger 555287944 error box
  88. GRB 180805B: ESO/NTT optical observations
  89. GRB 180805B: Swift-BAT refined analysis (short GRB with extended emission)
  90. Fermi Trigger 554765006: MASTER optical inspection
  91. FRB 180725A: MASTER optical observations of the Fast Radio Burst error box
  92. GRB 180728B: Fermi GBM detection
  93. IPN Triangulation of GRB 180728B (short)
  94. GRB 180728A: VLT/X-shooter redshift of a nearby energetic GRB
  95. GRB 180728A: Fermi GBM observation
  96. GRB 180728A: MASTER OT (= new object) detection
  97. GRB 180727A: Swift detection of a burst
  98. GRB 180718B: Swift-XRT observations
  99. GRB 180720B: MASTER Global Net OT observations
  100. GRB 180721A: MITSuME Akeno optical upper limits

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