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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

20506 results found.

  1. GRB 251122A / EP251122a: LCO optical upper limits
  2. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  3. GRB 251122A/EP251122a: SVOM/C-GFT upper limit
  4. GRB 251122A / EP251122a: SVOM detection of a long burst
  5. EP251122a: Einstein Probe detection of an X-ray transient
  6. EP251118a: Continued Optical Detection with Kinder observations
  7. LIGO/Virgo/KAGRA S251105aj: SVOM/ECLAIRs detection of a high-energy transient SVOM J2320.0-2901 through targeted search
  8. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  9. EP251118a: Xinglong-2.16m optical observation
  10. EP251118A: 1.3m DFOT optical afterglow detection
  11. GRB 251118A: Swift/UVOT Detection
  12. EP251118a / GRB 251118C: SAO RAS optical observations
  13. GRB 251118A: Swift-XRT afterglow detection
  14. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  15. EP251118a: Optical detection with Kinder observations
  16. LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
  17. EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
  18. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  19. EP251118A / GRB 251118C : MASTER optical counterpart observations
  20. GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
  21. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  22. EP251118a: VLT near-infrared observation
  23. GRB 251116D: SVOM/GRM observation of a long GRB
  24. GRB 251119A: SVOM detection of a possible burst
  25. EP251118a: NOT spectroscopic redshift of z = 1.216
  26. EP251118a: NOT candidate optical counterpart
  27. EP251118a: Einstein Probe detected of a fast X-ray transient
  28. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  29. GRB 251116C: SVOM/ECLAIRs refined analysis
  30. GRB 251116B: SVOM/ECLAIRs refined analysis
  31. GRB 251115A: Swift-XRT observations
  32. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  33. GRB 251117A: SVOM/GRM observation of a short burst
  34. GRB 251117A: Fermi-LAT detection
  35. LIGO/Virgo/KAGRA S251117dq: Identification of a GW compact binary merger candidate
  36. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  37. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  38. EP251023a: Assy AZT-20 optical observations
  39. EP251023a: UAFO and AbAO optical observations
  40. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  41. GRB 251025B: further Mondy optical observations
  42. GRB 251111A: Mondy optical upper limit
  43. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  44. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  45. GRB 251116B: LCO optical upper limits
  46. GRB 251116C: LCO optical upper limits
  47. IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
  48. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  49. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  50. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  51. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  52. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  53. GRB 251113A: AstroSat CZTI detection
  54. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  55. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  56. The EP-WXT trigger 01709248221 is likely a flaring star
  57. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  58. GRB 251111A: SVOM/ECLAIRs refined analysis
  59. GRB 251025B: SVOM/ECLAIRs refined analysis
  60. GRB 251112A: Swift/UVOT Upper Limits
  61. GRB 251108C: AstroSat CZTI detection
  62. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  63. Swift Trigger 1413695: a possible GRB 251112A
  64. GRB251111A: 1.3m DFOT optical upper limit
  65. GRB 251111A: Swift-XRT afterglow detection
  66. GRB 251111A: SVOM/VT optical observations with X-band data
  67. GRB 251111A: SVOM/VT optical observations with VHF data
  68. GRB 251111A: LCO optical observation
  69. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  70. GRB 251106A: Swift/UVOT Upper Limits
  71. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  72. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  73. IceCube-Cascade 251107A: Upper limits from a search for additional neutrino events in IceCube
  74. LIGO/Virgo/KAGRA S251108fi: Identification of a GW compact binary merger candidate
  75. GRB 251102B: SVOM/GRM observation
  76. LIGO/Virgo/KAGRA S251108dn: Identification of a GW compact binary merger candidate
  77. The EP-WXT trigger 01709248051 is likely a flaring star
  78. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
  79. GRB 251106A: Swift-XRT afterglow detection
  80. GRB 251106A: Kilonova-Catcher optical upper limit
  81. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  82. GRB 251106A: MASTER optical observations
  83. GRB 251103B: AstroSat CZTI detection
  84. EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart
  85. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  86. GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  87. GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
  88. GRB 251103B: Swift/UVOT Upper Limits
  89. LIGO/Virgo/KAGRA S251105aj: Identification of a GW compact binary merger candidate
  90. GRB 251103A: WFST optical observations
  91. GRB 251103A: OHP/T193 optical observations
  92. GRB 251103A: Xinglong 2.16m optical detection
  93. GRB 251103A: KAIT optical observations
  94. GRB 251103B: Nanshan/HMT optical upper limit
  95. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  96. GRB 251103B: MITSuME Akeno optical upper limits
  97. LIGO/Virgo/KAGRA S251103f: Identification of a GW compact binary merger candidate
  98. EP251102a: NIR observations with WINTER
  99. GRB 251103A: J-band detection with WINTER
  100. GRB 251103B: GROWTH-India Telescope optical upper limits

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